ABSTRACT
We searched for an isotropic stochastic gravitational wave background in the second data release of the International Pulsar Timing Array, a global collaboration synthesizing decadal-length ...pulsar-timing campaigns in North America, Europe, and Australia. In our reference search for a power-law strain spectrum of the form $h_c = A(f/1\, \mathrm{yr}^{-1})^{\alpha }$, we found strong evidence for a spectrally similar low-frequency stochastic process of amplitude $A = 3.8^{+6.3}_{-2.5}\times 10^{-15}$ and spectral index α = −0.5 ± 0.5, where the uncertainties represent 95 per cent credible regions, using information from the auto- and cross-correlation terms between the pulsars in the array. For a spectral index of α = −2/3, as expected from a population of inspiralling supermassive black hole binaries, the recovered amplitude is $A = 2.8^{+1.2}_{-0.8}\times 10^{-15}$. None the less, no significant evidence of the Hellings–Downs correlations that would indicate a gravitational-wave origin was found. We also analysed the constituent data from the individual pulsar timing arrays in a consistent way, and clearly demonstrate that the combined international data set is more sensitive. Furthermore, we demonstrate that this combined data set produces comparable constraints to recent single-array data sets which have more data than the constituent parts of the combination. Future international data releases will deliver increased sensitivity to gravitational wave radiation, and significantly increase the detection probability.
The observation of the recent electron neutrino appearance in a muon neutrino beam and the high-precision measurement of the mixing angle
$\theta _{13}$
have led to a re-evaluation of the physics ...potential of the T2K long-baseline neutrino oscillation experiment. Sensitivities are explored for CP violation in neutrinos, non-maximal
$\sin ^22\theta _{23}$
, the octant of
$\theta _{23}$
, and the mass hierarchy, in addition to the measurements of
$\delta _{{\rm CP}}$
,
$\sin ^2\theta _{23}$
, and
$\Delta m^2_{32}$
, for various combinations of
$\nu$
-mode and
$\bar {\nu }$
-mode data-taking.
With an exposure of
$7.8\times 10^{21}$
protons-on-target, T2K can achieve 1
$\sigma$
resolution of 0.050 (0.054) on
$\sin ^2\theta _{23}$
and
$0.040\ (0.045)\times 10^{-3}\,\rm {eV}^2$
on
$\Delta m^2_{32}$
for 100% (50%) neutrino beam mode running assuming
$\sin ^2\theta _{23}=0.5$
and
$\Delta m^2_{32} = 2.4\times 10^{-3}\,\hbox {eV}^2$
. T2K will have sensitivity to the CP-violating phase
$\delta _{\rm {CP}}$
at 90% C.L. or better over a significant range. For example, if
$\sin ^22\theta _{23}$
is maximal (i.e.
$\theta _{23}=45^\circ$
) the range is
$-115^\circ \lt \delta _{\rm {CP}}\lt -60^\circ$
for normal hierarchy and
$+50^\circ \lt \delta _{\rm {CP}}\lt +130^\circ$
for inverted hierarchy. When T2K data is combined with data from the NO
$\nu$
A experiment, the region of oscillation parameter space where there is sensitivity to observe a non-zero
$\delta _{{\rm CP}}$
is substantially increased compared to if each experiment is analyzed alone.
Background
Screening data from the Anti-Amyloid Treatment in Asymptomatic Alzheimer’s Disease (A4) and Longitudinal Evaluation of Amyloid Risk and Neurodegeneration (LEARN) studies provide a unique ...opportunity to compare magnetic resonance imaging (MRI) findings such as amyloid-related imaging abnormalities (ARIA) in cognitively unimpaired elderly with and without elevated cerebral amyloid.
Objectives
To compare screening MRI findings, such as ARIA, in the cognitively unimpaired potential participants of a clinical trial with and without elevated cerebral amyloid.
Design
Cross-sectional analysis of structural MRI findings in screening data from the A4 and LEARN studies.
Setting
The A4 Study is a multi-center international clinical trial. The LEARN Study is a multi center observational study in the United States.
Participants
Clinically normal older adults (65–85 years) with elevated cerebral amyloid (Aβ+; n = 1250, A4) and without elevated cerebral amyloid (Aβ-; n = 538, LEARN).
Measurements
Participants underwent florbetapir positron emission tomography for Aβ+/- classification. A centrally read 3T MRI to assess for study eligibility was conducted on study qualified MRI scanners.
Results
No ARIA-effusions (ARIA-E) was detected on screening MRI in the Aβ+ or Aβ- cohorts. At least one ARIA-H (microhemorrhages MCH or superficial siderosis SS) was present in 18% of the Aβ+ cohort compared with 8% in Aβ- (P < 0.001). In the Aβ+ cohort, approximately 2% of screening MRIs demonstrated MCH ≥4 compared with 0% in Aβ-. The presence of two apolipoprotein E ε4 (APOEε4) alleles (vs no ε4 alleles) in the Aβ+ cohort increased the odds for presence of MCH (odds ratio OR = 2.03; 95% CI, 1.23 to 3.27, P = 0.004). Cortical infarctions (4% vs 0%) and subcortical infarctions (10% vs 1%) were observed at statistically significantly higher prevalence in the Aβ+ cohort compared with Aβ- (P < 0.001). Females showed reduced odds of MCH in the Aβ+ cohort by a factor of 0.63 (95% CI, 0.47 to 0.84, P = 0.002).
Conclusions
ARIA-E is rare in cognitively unimpaired Aβ+ and Aβ- populations prior to anti-amyloid drug intervention. ARIA-H in Aβ+ was greater than in Aβ- populations.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Patients with resected colorectal cancer are at risk for recurrent cancer and metachronous neoplasms in the colon. This joint update of guidelines by the American Cancer Society (ACS) and US ...Multi‐Society Task Force on Colorectal Cancer addresses only the use of endoscopy in the surveillance of these patients. Patients with endoscopically resected Stage I colorectal cancer, surgically resected Stage II and III cancers, and Stage IV cancer resected for cure (isolated hepatic or pulmonary metastasis) are candidates for endoscopic surveillance. The colorectum should be carefully cleared of synchronous neoplasia in the perioperative period. In nonobstructed colons, colonoscopy should be performed preoperatively. In obstructed colons, double contrast barium enema or computed tomography colonography should be done preoperatively, and colonoscopy should be performed 3 to 6 months after surgery. These steps complete the process of clearing synchronous disease. After clearing for synchronous disease, another colonoscopy should be performed in 1 year to look for metachronous lesions. This recommendation is based on reports of a high incidence of apparently metachronous second cancers in the first 2 years after resection. If the examination at 1 year is normal, then the interval before the next subsequent examination should be 3 years. If that colonoscopy is normal, then the interval before the next subsequent examination should be 5 years. Shorter intervals may be indicated by associated adenoma findings (see Postpolypectomy Surveillance Guideline). Shorter intervals are also indicated if the patient's age, family history, or tumor testing indicate definite or probable hereditary nonpolyposis colorectal cancer. Patients undergoing low anterior resection of rectal cancer generally have higher rates of local cancer recurrence, compared with those with colon cancer. Although effectiveness is not proven, performance of endoscopic ultrasound or flexible sigmoidoscopy at 3‐ to 6‐month intervals for the first 2 years after resection can be considered for the purpose of detecting a surgically curable recurrence of the original rectal cancer.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Over 40 years ago, the dacetine ant
Strumigenys arizonica
was discovered in a nest of the fungus-growing ant
Trachymyrmex arizonensis
at Madera Canyon in the Santa Rita Mountains of the southwestern ...United States. This discovery suggested that the two species form compound nests, but this hypothesis has not been investigated. Here, we characterize this symbiosis through an analysis of collection records supplemented by recent field and laboratory observations. Our observations show that
S. arizonica
and
T. arizonensis
form compound nests that are a type of commensalistic symbiosis. Individuals of
S. arizonica
forage in galleries and tunnels of
T. arizonensis
nests but do not steal fungus or brood. Instead, individuals of
S. arizonica
hunt collembolans in the internal refuse piles of
T. arizonensis
nests. Interestingly,
S. arizonica
was never found independent of its host
T. arizonensis
over a significant portion of the geographic range of
T. arizonensis
. These results suggest a tight but asymmetric association where compound nesting is obligate for
S. arizonica
and facultative for
T. arizonensis
.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
► Extended survival of several organisms under simulated Mars-like conditions. ► Majority of cell loss attributed to desiccation and oxidation related stresses. ► Desiccation and radio-tolerant ...organisms show significantly longer lifetimes. ► Amino acid oxidation controlled by the diffusion-limited formation of peroxide.
Recent orbital and landed missions have provided substantial evidence for ancient liquid water on the martian surface as well as evidence of more recent sedimentary deposits formed by water and/or ice. These observations raise serious questions regarding an independent origin and evolution of life on Mars. Future missions seek to identify signs of extinct martian biota in the form of biomarkers or morphological characteristics, but the inherent danger of spacecraft-borne terrestrial life makes the possibility of forward contamination a serious threat not only to the life detection experiments, but also to any extant martian ecosystem. A variety of cold and desiccation-tolerant organisms were exposed to 40
days of simulated martian surface conditions while embedded within several centimeters of regolith simulant in order to ascertain the plausibility of such organisms’ survival as a function of environmental parameters and burial depth. Relevant amino acid biomarkers associated with terrestrial life were also analyzed in order to understand the feasibility of detecting chemical evidence for previous biological activity. Results indicate that stresses due to desiccation and oxidation were the primary deterrent to organism survival, and that the effects of UV-associated damage, diurnal temperature variations, and reactive atmospheric species were minimal. Organisms with resistance to desiccation and radiation environments showed increased levels of survival after the experiment compared to organisms characterized as psychrotolerant. Amino acid analysis indicated the presence of an oxidation mechanism that migrated downward through the samples during the course of the experiment and likely represents the formation of various oxidizing species at mineral surfaces as water vapor diffused through the regolith. Current sterilization protocols may specifically select for organisms best adapted to survival at the martian surface, namely species that show tolerance to radical-induced oxidative damage and low water activity environments. Additionally, any hypothetical martian ecosystems may have evolved similar physiological traits that allow sporadic metabolism during periods of increased water activity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Summary
Purpose: The aim of this study was to evaluate if men with varying degrees of bother from a similar number of nocturia episodes differ with respect to self‐rated sleep characteristics and ...fatigue.
Materials and methods: As part of the baseline assessments during a nocturia treatment trial, 55 participants reported frequency and bother of nocturia using the AUA Symptom Inventory and completed 7‐day sleep diaries prior to treatment. Participants who reported moderate nocturia (either two or three episodes nightly) were further grouped into categories of LOW (nocturia is no problem or a very small problem) or HIGH bother (nocturia is a big problem). Information from the participant completed sleep diaries was ed, including information on daytime napping, total sleep time, mean time needed to return to sleep, nighttime ratings of fatigue, and daytime ratings of fatigue.
Results: Of the 55 individuals who completed the pilot study, 24 study participants reported two or three episodes of nocturia and had either HIGH (n = 11) or LOW (n = 13) bother. Participants categorised with HIGH bother were significantly more likely than those with LOW bother to report difficulty initiating sleep (47.7 ± 34.4 vs. 23.5 ± 13.6 min, p = 0.05), difficulty returning to sleep after an awakening (28.9 ± 16.1 vs. 15.4 ± 9.6 min, p = 0.03) and greater morning fatigue (3.3 ± 0.7 vs. 2.5 ± 1.0, p = 0.04 on a 7‐point scale).
Conclusions: Since bother related to nocturia is linked to sleep quality, interventions targeting fatigue and sleep maintenance may provide useful targets in the management of nocturia in men.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
OBJECTIVE
To determine predictors of systolic anterior motion and left ventricular outflow tract obstruction (SAM/LVOTO) after mitral valve repair (MVRep) in patients with myxomatous mitral valve ...disease.
BACKGROUND
Mechanisms for the development of SAM/LVOTO after MVRep have been described; however, predictors of this complication have not been explored. We hypothesize that pre-MVRep transesophageal echocardiography (TEE) can predict postrepair SAM/LVOTO.
METHODS
Using TEE, the lengths of the coapted anterior (AL) and posterior (PL) leaflets and the distance from the coaptation point to the septum (C-Sept) were measured before and after MVRep in 33 patients, including 11 who developed SAM/LVOTO (Group 1) and 22 who did not (Group 2).
RESULTS
Group 1 patients had smaller AL/PL ratios (0.99 vs. 1.95, p < 0.0001) and C-Sept distances (2.53 vs. 3.01 cm, p = 0.012) prior to MVRep than those in Group 2. Resolution of SAM/LVOTO was associated with increases in AL/PL ratio and C-Sept distance. This reflects a more anterior position of the coaptation point in those who developed SAM/LVOTO.
CONCLUSIONS
These data suggest that TEE analysis of the mitral apparatus can identify patients likely to develop SAM/LVOTO after MVRep for myxomatous valve disease. The findings are consistent with the concept that SAM of mitral leaflets is due to anterior malposition of slack mitral leaflet portions into the LVOT. The position of the coaptation point of the mitral leaflets is dynamic and a potential target and end point for surgical designs to prevent SAM/LVOTO post MVRep.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The ion mass spectrometer on Cassini detected enhanced ion flux near Saturn's main rings that is consistent with the presence of atomic and molecular oxygen ions in the thermal plasma. The ring ...“atmosphere” and “ionosphere” are likely produced by UV photosputtering of the icy rings and subsequent photoionization of O2. The identification of the O+ and O2+ ions is made using time‐of‐flight analysis and densities and temperatures are derived from the ion counting data. The ion temperatures over the main rings are a minimum near synchronous orbit and increase with radial distance from Saturn as expected from ion pick up in Saturn's magnetic field. The O2+ temperatures provide an estimate of the neutral O2 temperature over the main rings. The ion mass spectrometer also detected significant O2+ outside of the main rings, near the F ring. It is concluded that between the F and G rings, the heavy ion population most likely consists of an admixture of O2+ and water group ions O+, OH+, and H2O+.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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