2,280 research outputs found
Is "Better Data" Better than "Better Data Miners"? (On the Benefits of Tuning SMOTE for Defect Prediction)
We report and fix an important systematic error in prior studies that ranked
classifiers for software analytics. Those studies did not (a) assess
classifiers on multiple criteria and they did not (b) study how variations in
the data affect the results. Hence, this paper applies (a) multi-criteria tests
while (b) fixing the weaker regions of the training data (using SMOTUNED, which
is a self-tuning version of SMOTE). This approach leads to dramatically large
increases in software defect predictions. When applied in a 5*5
cross-validation study for 3,681 JAVA classes (containing over a million lines
of code) from open source systems, SMOTUNED increased AUC and recall by 60% and
20% respectively. These improvements are independent of the classifier used to
predict for quality. Same kind of pattern (improvement) was observed when a
comparative analysis of SMOTE and SMOTUNED was done against the most recent
class imbalance technique. In conclusion, for software analytic tasks like
defect prediction, (1) data pre-processing can be more important than
classifier choice, (2) ranking studies are incomplete without such
pre-processing, and (3) SMOTUNED is a promising candidate for pre-processing.Comment: 10 pages + 2 references. Accepted to International Conference of
Software Engineering (ICSE), 201
Systematics of Microhylid Frogs, Genus Oreophryne, from the North Coast Region of New Guinea
Fig. 4. Regression of internarial span on snoutÂvent length in two samples of Oreophryne biroi from Papua New Guinea. Squares, specimens from Madang Prov.; crosses, specimens from East Sepik Prov.Published as part of <i>ZWEIFEL, RICHARD G., MENZIES, JAMES I. & PRICE, DAVID, 2003, Systematics of Microhylid Frogs, Genus Oreophryne, from the North Coast Region of New Guinea, pp. 1-32 in American Museum Novitates 3415</i> on page 10, DOI: 10.1206/0003-0082(2003)415<0001:SOMFGO>2.0.CO;2, <a href="http://zenodo.org/record/10111440">http://zenodo.org/record/10111440</a>
Green waste compost reduces nitrous oxide emissions from feedlot manure applied to soil
Australia produces in excess of 1 million tonnes of feedlot manure (FLM) annually. Application of FLM to grain cropping and grazing soils could provide a valuable nutrient resource. However, because of high nutrient concentration, especially of N (>2%), FLM has the potential for environmental pollution, for example, N pollution to the water bodies and NO emission to the atmosphere. Therefore, controlling N supply from FLM is essential for the judicious utilisation of FLM in the field as well as reducing NO emission to the atmosphere. We utilised the low N concentration green waste compost (GWC, about 3 million tonnes produced annually) as a potential management tool to assess its effectiveness in regulating N release from FLM and controlling the rates of NO emission from field application when both FLM and GWC were applied together to sorghum (Sorghum bicolor Moench) grown on a Vertisol. We measured NO emission rates during the sorghum crop and clean fallowing over one-year period in the field. Annual soil NO emissions were 5.0 kg NO ha from urea applied at 150 kg N ha, 5.1 and 5.5 kg NO ha from FLM applied at 10 and 20 t ha respectively, 2.2 kg NO ha from GWC applied at 10 t ha, 4.3 kg NO ha from FLM and GWC applied together at 10 t ha each, and 3.3 kg NO ha from the unamended soil. Thus, we found that GWC application reduced NO emissions below those from an unamended soil while annual emission rate from FLM approached that from fertiliser N application (âŒ0.7% NO emission factor). A mixture of FLM + GWC applied at 10 t ha each reduced NO emission factor by 64% (the emission factor was 0.22%), most likely by reducing the amount of mineral N in the soil because soil NH-N and NO-N and the rate of NO emission were significantly correlated in this soil. Since the global warming potential of NO is 298 times that of CO, even a small reduction in NO emission from GWC application has a significant and positive impact on reducing global warming
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A near-infrared study of AGB and red giant stars in the Leo I dSph galaxy
A near-infrared imaging study of the evolved stellar populations in the dwarf
spheroidal galaxy Leo I is presented. Based on JHK observations obtained with
the WFCAM wide-field array at the UKIRT telescope, we build a near-infrared
photometric catalogue of red giant branch (RGB) and asymptotic giant branch
(AGB) stars in Leo I over a 13.5 arcmin square area. The V-K colours of RGB
stars, obtained by combining the new data with existing optical observations,
allow us to derive a distribution of global metallicity [M/H] with average
[M/H] = -1.51 (uncorrected) or [M/H] = -1.24 +/- 0.05 (int) +/- 0.15 (syst)
after correction for the mean age of Leo I stars. This is consistent with the
results from spectroscopy once stellar ages are taken into account. Using a
near-infrared two-colour diagram, we discriminate between carbon- and
oxygen-rich AGB stars and obtain a clean separation from Milky Way foreground
stars. We reveal a concentration of C-type AGB stars relative to the red giant
stars in the inner region of the galaxy, which implies a radial gradient in the
intermediate-age (1-3 Gyr) stellar populations. The numbers and luminosities of
the observed carbon- and oxygen-rich AGB stars are compared with those
predicted by evolutionary models including the thermally-pulsing AGB phase, to
provide new constraints to the models for low-metallicity stars. We find an
excess in the predicted number of C stars fainter than the RGB tip, associated
to a paucity of brighter ones. The number of O-rich AGB stars is roughly
consistent with the models, yet their predicted luminosity function is extended
to brighter luminosity. It appears likely that the adopted evolutionary models
overestimate the C star lifetime and underestimate their K-band luminosity.Comment: MNRAS, accepte
PI(5)P regulates autophagosome biogenesis.
Phosphatidylinositol 3-phosphate (PI(3)P), the product of class III PI3K VPS34, recruits specific autophagic effectors, like WIPI2, during the initial steps of autophagosome biogenesis and thereby regulates canonical autophagy. However, mammalian cells can produce autophagosomes through enigmatic noncanonical VPS34-independent pathways. Here we show that PI(5)P can regulate autophagy via PI(3)P effectors and thereby identify a mechanistic explanation for forms of noncanonical autophagy. PI(5)P synthesis by the phosphatidylinositol 5-kinase PIKfyve was required for autophagosome biogenesis, and it increased levels of PI(5)P, stimulated autophagy, and reduced the levels of autophagic substrates. Inactivation of VPS34 impaired recruitment of WIPI2 and DFCP1 to autophagic precursors, reduced ATG5-ATG12 conjugation, and compromised autophagosome formation. However, these phenotypes were rescued by PI(5)P in VPS34-inactivated cells. These findings provide a mechanistic framework for alternative VPS34-independent autophagy-initiating pathways, like glucose starvation, and unravel a cytoplasmic function for PI(5)P, which previously has been linked predominantly to nuclear roles.We are grateful for funding from a Wellcome Trust Principal Research Fellowship (095317/Z/11/Z to D.C.R.), a Wellcome Trust Strategic Award (100140/Z/ 12/Z), the NIHR Biomedical Research Centre in Dementia at Addenbrookeâs Hospital, an MRC Confidence in Concepts grant (D.C.R.), and a FEBS Long- Term Fellowship (A.A.).This article was originally published in Molecular Cell (M Vicinanza, VI Korolchuk, A Ashkenazi, C Puri, FM Menzies, JH Clarke, DC Rubinsztein, Molecular Cell 2015, 57, 219-234
Geochemical and isotopic insights into the assembly, evolution and disruption of a magmatic plumbing system before and after a cataclysmic caldera-collapse eruption at Ischia volcano (Italy)
New geochemical and isotopic data on volcanic rocks spanning the period ~75â50 ka BP on Ischia volcano, Italy, shed light on the evolution of the magmatic system before and after the catastrophic, caldera-forming Monte Epomeo Green Tuff (MEGT) eruption. Volcanic activity during this period was influenced by a large, composite and differentiating magmatic system, replenished several times with isotopically distinct magmas of deep provenance. Chemical and isotopic variations highlight that the pre-MEGT eruptions were fed by trachytic/phonolitic magmas from an isotopically zoned reservoir that were poorly enriched in radiogenic Sr and became progressively less radiogenic with time. Just prior to the MEGT eruption, the magmatic system was recharged by an isotopically distinct magma, relatively more enriched in radiogenic Sr with respect to the previously erupted magmas. This second magma initially fed several SubPlinian explosive eruptions and later supplied the climactic, phonolitic-to-trachytic MEGT eruption(s). Isotopic data, together with erupted volume estimations obtained for MEGT eruption(s), indicate that >5â10 km3 of this relatively enriched magma had accumulated in the Ischia plumbing system. Geochemical modelling indicates that it accumulated at shallow depths (4â6 km), over a period of ca. 20 ka. After the MEGT eruption, volcanic activity was fed by a new batch of less differentiated (trachyte-latite) magma that was slightly less enriched in radiogenic Sr. The geochemical and SrâNd-isotopic variations through time reflect the upward flux of isotopically distinct magma batches, variably contaminated by Hercynian crust at 8â12 km depth. The deep-sourced latitic to trachytic magmas stalled at shallow depths (4â6 km depth), differentiated to phonolite through crystal fractionation and assimilation of a feldspar-rich mush, or ascended directly to the surface and erupted
Palliative care in UK prisons: practical and emotional challenges for staff and fellow prisoners
Despite falling crime rates in England and Wales over the past 20 years, the number of prisoners has doubled. People over the age of 50 constitute the fastest growing section of the prison population, and increasing numbers of older prisoners are dying in custody. This article discusses some of the issues raised by these changing demographics and draws on preliminary findings from a study underway in North West England. It describes the context behind the rise in the numbers of older prisoners; explores the particular needs of this growing population; and discusses some of the practical and emotional challenges for prison officers, health care staff, and fellow prisoners who are involved in caring for dying prisoners in a custodial environment
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