75 research outputs found
Certification (and) Marks – Understanding Usage and Practices Among Standards Organizations
In addition to creating technical standards that describe how different products or services interoperate, many standards development organizations (SDOs) also perform testing services that are designed to ensure that products that ostensibly comply with a standard actually work together. SDOs frequently call this process “certification,” and authorize implementers that pass the testing process to use a logo or similar mark. Certification marks are a type of trademark that would seem to be tailor-made for this process. Our empirical analysis shows that SDOs use certification marks only relatively rarely, however. This dissonance is striking, providing insight into both the remarkably sophisticated practices of many SDOs in connection with compliance and interoperability testing and into potential weaknesses of the certification mark legal regime. The empirical data presented in the paper is intended to serve as a foundational platform for further work analysing the law and policy of certification marks and the practices of SDOs in connection with interoperability testing and certification
Near-infrared observations of type Ia supernovae: The best known standard candle for cosmology
We present an analysis of the Hubble diagram for 12 Type Ia supernovae (SNe
Ia) observed in the near-infrared J and H bands. We select SNe exclusively from
the redshift range 0.03 < z < 0.09 to reduce uncertainties coming from peculiar
velocities while remaining in a cosmologically well-understood region. All of
the SNe in our sample exhibit no spectral or B-band light-curve peculiarities
and lie in the B-band stretch range of 0.8-1.15. Our results suggest that SNe
Ia observed in the near-infrared (NIR) are the best known standard candles. We
fit previously determined NIR light-curve templates to new high-precision data
to derive peak magnitudes and to determine the scatter about the Hubble line.
Photometry of the 12 SNe is presented in the natural system. Using a standard
cosmology of (H_0, Omega_m, Lambda) = (70,0.27,0.73) we find a median J-band
absolute magnitude of M_J = -18.39 with a scatter of 0.116 and a median H-band
absolute magnitude of M_H = -18.36 with a scatter of 0.085. The scatter in the
H band is the smallest yet measured. We search for correlations between
residuals in the J- and H-band Hubble diagrams and SN properties, such as SN
colour, B-band stretch and the projected distance from host-galaxy centre. The
only significant correlation is between the J-band Hubble residual and the J-H
pseudo-colour. We also examine how the scatter changes when fewer points in the
near-infrared are used to constrain the light curve. With a single point in the
H band taken anywhere from 10 days before to 15 days after B-band maximum light
and a prior on the date of H-band maximum set from the date of B-band maximum,
we find that we can measure distances to an accuracy of 6%. The precision of
SNe Ia in the NIR provides new opportunities for precision measurements of both
the expansion history of the universe and peculiar velocities of nearby
galaxies.Comment: 6 pages, 2 figures. Accepted for publication in MNRA
NTT and NOT spectroscopy of SDSS-II supernovae
Context. The SDSS-II Supernova Survey, conducted between 2005 and 2007, was
designed to detect a large number of Type Ia supernovae (SNe Ia) around z~0.2,
the redshift "gap" between low-z and high-z SN searches. The survey has
provided multi-band photometric lightcurves for variable targets, and SN
candidates were scheduled for spectroscopic observations, primarily to provide
SN classification and accurate redshifts. We present SN spectra obtained in
2006 and 2007 using the NTT and the NOT. Aims. We provide an atlas of SN
spectra in the range z =0.03-0.32 that complements the well-sampled lightcurves
from SDSS-II in the forthcoming three-year SDSS SN cosmology analysis. The
sample can, for example, be used for spectral studies of SNe Ia, which are
critical for understanding potential systematic effects when SNe are used to
determine cosmological distances. Methods. The spectra were reduced in a
uniform manner, and special care was taken in estimating the uncertainties for
the different processing steps. Host-galaxy light was subtracted when possible
and the SN type fitted using the SuperNova IDentification code (SNID). We also
present comparisons between spectral and photometric dating using SALT
lightcurve fits to the photometry from SDSS-II, as well as the global
distribution of our sample in terms of the lightcurve parameters: stretch and
colour. Results. We report new spectroscopic data from 141 SNe Ia, mainly
between -9 and +15 days from lightcurve maximum, including a few cases of
multi-epoch observations. This homogeneous, host-galaxy subtracted, SN Ia
spectroscopic sample is among the largest such data sets and unique in its
redshift interval. The sample includes two potential SN 1991T-like SNe (SN
2006on and SN 2007ni) and one potential SN 2002cx-like SN (SN 2007ie). In
addition, the new compilation includes spectra from 23 confirmed Type II and 8
Type Ib/c SNe.Comment: Accepted for publication in A&
Rates and properties of type Ia supernovae as a function of mass and star-formation in their host galaxies
(ABRIDGED) We show that Type Ia supernovae (SNe Ia) are formed within both
very young and old stellar populations, with observed rates that depend on the
stellar mass and mean star-formation rates (SFRs) of their host galaxies.
Models where the SN Ia rate depends solely on host galaxy stellar mass are
ruled out with 99% confidence. Our analysis is based on 100
spectroscopically-confirmed SNe Ia, plus 24 photometrically-classified events,
all from the Supernova Legacy Survey (SNLS) and distributed over 0.2<z<0.75.
Using multi-band photometry, we estimate stellar masses and SFRs for the SN Ia
host galaxies by fitting their broad-band spectral energy distributions with
the galaxy spectral synthesis code, PEGASE.2. We show that the SN Ia rate per
unit mass is proportional to the specific SFR of the parent galaxies -- more
vigorously star-forming galaxies host more SNe Ia per unit stellar mass,
broadly equivalent to the trend of increasing SN Ia rate in later-type galaxies
seen in the local universe. Following earlier suggestions for a simple
"two-component" model approximating the SN Ia rate, we find bivariate linear
dependencies of the SN Ia rate on both the stellar masses and the mean SFRs of
the host systems. We also demonstrate a dependence of distant SN Ia light-curve
shapes on star-formation in the host galaxy, similar to trends observed
locally. Passive galaxies, with no star-formation, preferentially host
faster-declining/dimmer SNe Ia, while slower-declining/brighter events are only
found in systems with ongoing star-formation. We model the light-curve width
distribution in star-forming galaxies as the sum of a young component, and an
old component taken from the distribution in non-star-forming galaxies.Comment: Accepted for publication in Ap
The p38 alpha Stress Kinase Suppresses Aneuploidy Tolerance by Inhibiting Hif-1 alpha
Deviating from the normal karyotype dramatically changes gene dosage, in turn decreasing the robustness of biological networks. Consequently, aneuploidy is poorly tolerated by normal somatic cells and acts as a barrier to transformation. Paradoxically, however, karyotype heterogeneity drives tumor evolution and the emergence of therapeutic drug resistance. To better understand how cancer cells tolerate aneuploidy, we focused on the p38 stress response kinase. We show here that p38-deficient cells upregulate glycolysis and avoid post-mitotic apoptosis, leading to the emergence of aneuploid subclones. We also show that p38 deficiency upregulates the hypoxia-inducible transcription factor Hif-1 alpha and that inhibiting Hif-1 alpha restores apoptosis in p38-deficent cells. Because hypoxia and aneuploidy are both barriers to tumor progression, the ability of Hif-1 alpha to promote cell survival following chromosome missegregation raises the possibility that aneuploidy tolerance coevolves with adaptation to hypoxia
World Society of Emergency Surgery (WSES) guidelines for management of skin and soft tissue infections
Peer reviewe
Evaluation of appendicitis risk prediction models in adults with suspected appendicitis
Background
Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis.
Methods
A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis).
Results
Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent).
Conclusion
Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified
Feasibility of preoperative chemotherapy for locally advanced, operable colon cancer: The pilot phase of a randomised controlled trial
Summary:
Background Preoperative (neoadjuvant) chemotherapy and radiotherapy are more eff ective than similar postoperative
treatment for oesophageal, gastric, and rectal cancers, perhaps because of more eff ective micrometastasis eradication
and reduced risk of incomplete excision and tumour cell shedding during surgery. The FOxTROT trial aims to
investigate the feasibility, safety, and effi cacy of preoperative chemotherapy for colon cancer.
Methods In the pilot stage of this randomised controlled trial, 150 patients with radiologically staged locally advanced
(T3 with ≥5 mm invasion beyond the muscularis propria or T4) tumours from 35 UK centres were randomly
assigned (2:1) to preoperative (three cycles of OxMdG [oxaliplatin 85 mg/m², l-folinic acid 175 mg, fl uorouracil
400 mg/m² bolus, then 2400 mg/m² by 46 h infusion] repeated at 2-weekly intervals followed by surgery and a
further nine cycles of OxMdG) or standard postoperative chemotherapy (12 cycles of OxMdG). Patients with KRAS
wild-type tumours were randomly assigned (1:1) to receive panitumumab (6 mg/kg; every 2 weeks with the fi rst
6 weeks of chemotherapy) or not. Treatment allocation was through a central randomisation service using a
minimised randomisation procedure including age, radiological T and N stage, site of tumour, and presence of
defunctioning colostomy as stratifi cation variables. Primary outcome measures of the pilot phase were feasibility,
safety, and tolerance of preoperative therapy, and accuracy of radiological staging. Analysis was by intention to treat.
This trial is registered, number ISRCTN 87163246.
Findings 96% (95 of 99) of patients started and 89% (85 of 95) completed preoperative chemotherapy with grade 3–4
gastrointestinal toxicity in 7% (seven of 94) of patients. All 99 tumours in the preoperative group were resected, with
no signifi cant diff erences in postoperative morbidity between the preoperative and control groups: 14% (14 of 99)
versus 12% (six of 51) had complications prolonging hospital stay (p=0·81). 98% (50 of 51) of postoperative
chemotherapy patients had T3 or more advanced tumours confi rmed at post-resection pathology compared with 91%
(90 of 99) of patients following preoperative chemotherapy (p=0·10). Preoperative therapy resulted in signifi cant
downstaging of TNM5 compared with the postoperative group (p=0·04), including two pathological complete
responses, apical node involvement (1% [one of 98] vs 20% [ten of 50], p<0·0001), resection margin involvement (4%
[ four of 99] vs 20% [ten of 50], p=0·002), and blinded centrally scored tumour regression grading: 31% (29 of 94) vs 2%
(one of 46) moderate or greater regression (p=0·0001).
Interpretation Preoperative chemotherapy for radiologically staged, locally advanced operable primary colon cancer is
feasible with acceptable toxicity and perioperative morbidity. Proceeding to the phase 3 trial, to establish whether the
encouraging pathological responses seen with preoperative therapy translates into improved long-term oncological
outcome, is appropriate
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Evaluation of state taxes and tax incentives and their impact on the development of geothermal energy in western states
The economic impact of existing and prospective state taxes and tax incentives on direct thermal applications of geothermal energy are evaluated. Study area is twelve western states which have existing and potential geothermal activities. Economic models representing the geothermal producer and business enterprise phases of four industrial/commercial uses of geothermal energy are synthesized and then placed in the existing tax structures of each state for evaluation. The four enterprises are a commercial greenhouse (low temperature process heat), apartment complex (low temperature space heat), food processor (moderate temperature process heat), and small scale energy system (electrical and direct thermal energy for a small industrial park). The effects of the state taxations on net profits and tax revenues are determined. Tax incentives to accelerate geothermal development are also examined. The magnitudes of total state and local tax collections vary considerably from state to state, which implies that geothermal producers and energy-using businesses may be selective in expanding or locating their geothermal operations
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