130 research outputs found
Anomaly Cancelation in Field Theory and F-theory on a Circle
We study the manifestation of local gauge anomalies of four- and
six-dimensional field theories in the lower-dimensional Kaluza-Klein theory
obtained after circle compactification. We identify a convenient set of
transformations acting on the whole tower of massless and massive states and
investigate their action on the low-energy effective theories in the Coulomb
branch. The maps employ higher-dimensional large gauge transformations and
precisely yield the anomaly cancelation conditions when acting on the one-loop
induced Chern-Simons terms in the three- and five-dimensional effective theory.
The arising symmetries are argued to play a key role in the study of the
M-theory to F-theory limit on Calabi-Yau manifolds. For example, using the fact
that all fully resolved F-theory geometries inducing multiple Abelian gauge
groups or non-Abelian groups admit a certain set of symmetries, we are able to
generally show the cancelation of pure Abelian or pure non-Abelian anomalies in
these models.Comment: 48 pages, 2 figures; v2: typos corrected, comments on circle fluxes
adde
D3-brane Potentials from Fluxes in AdS/CFT
We give a comprehensive treatment of the scalar potential for a D3-brane in a
warped conifold region of a compactification with stabilized moduli. By
studying general ultraviolet perturbations in supergravity, we systematically
incorporate `compactification effects' sourced by supersymmetry breaking in the
compact space. Significant contributions to the D3-brane potential, including
the leading term in the infrared, arise from imaginary anti-self-dual (IASD)
fluxes. For an arbitrary Calabi-Yau cone, we determine the most general IASD
fluxes in terms of scalar harmonics, then compute the resulting D3-brane
potential. Specializing to the conifold, we identify the operator dual to each
mode of flux, and for chiral operators we confirm that the potential computed
in the gauge theory matches the gravity result. The effects of four-dimensional
curvature, including the leading D3-brane mass term, arise directly from the
ten-dimensional equations of motion. Furthermore, we show that gaugino
condensation on D7-branes provides a local source for IASD flux. This flux
precisely encodes the nonperturbative contributions to the D3-brane potential,
yielding a promising ten-dimensional representation of four-dimensional
nonperturbative effects. Our result encompasses all significant contributions
to the D3-brane potential discussed in the literature, and does so in the
single coherent framework of ten-dimensional supergravity. Moreover, we
identify new terms with irrational scaling dimensions that were inaccessible in
prior works. By decoupling gravity in a noncompact configuration, then
systematically reincorporating compactification effects as ultraviolet
perturbations, we have provided an approach in which Planck-suppressed
contributions to the D3-brane effective action can be computed.Comment: 70 page
Six-dimensional (1,0) effective action of F-theory via M-theory on Calabi-Yau threefolds
The six-dimensional effective action of F-theory compactified on a singular
elliptically fibred Calabi-Yau threefold is determined by using an M-theory
lift. The low-energy data are derived by comparing a circle reduction of a
general six-dimensional (1,0) gauged supergravity theory with the effective
action of M-theory on the resolved Calabi-Yau threefold. The derivation
includes six-dimensional tensor multiplets for which the (anti-) self-duality
constraints are imposed on the level of the five-dimensional action. The vector
sector of the reduced theory is encoded by a non-standard potential due to the
Green-Schwarz term in six dimensions. This Green-Schwarz term also contains
higher curvature couplings which are considered to establish the full map
between anomaly coefficients and geometry. F-/M-theory duality is exploited by
moving to the five-dimensional Coulomb branch after circle reduction and
integrating out massive vector multiplets and matter hypermultiplets. The
associated fermions then generate additional Chern-Simons couplings at
one-loop. Further couplings involving the graviphoton are induced by quantum
corrections due to excited Kaluza-Klein modes. On the M-theory side integrating
out massive fields corresponds to resolving the singularities of the Calabi-Yau
threefold, and yields intriguing relations between six-dimensional anomalies
and classical topology.Comment: 55 pages, v2: typos corrected, discussion of loop corrections
improve
Massive Abelian Gauge Symmetries and Fluxes in F-theory
F-theory compactified on a Calabi-Yau fourfold naturally describes
non-Abelian gauge symmetries through the singularity structure of the elliptic
fibration. In contrast Abelian symmetries are more difficult to study because
of their inherently global nature. We argue that in general F-theory
compactifications there are massive Abelian symmetries, such as the uplift of
the Abelian part of the U(N) gauge group on D7-branes, that arise from
non-Kahler resolutions of the dual M-theory setup. The four-dimensional
F-theory vacuum with vanishing expectation values for the gauge fields
corresponds to the Calabi-Yau limit. We propose that fluxes that are turned on
along these U(1)s are uplifted to non-harmonic four-form fluxes. We derive the
effective four-dimensional gauged supergravity resulting from F-theory
compactifications in the presence of the Abelian gauge factors including the
effects of possible fluxes on the gauging, tadpoles and matter spectrum.Comment: 49 page
Physiological and autonomic stress responses after prolonged sleep restriction and subsequent recovery sleep in healthy young men
Purpose Sleep restriction is increasingly common and associated with the development of health problems. We investigated how the neuroendocrine stress systems respond to prolonged sleep restriction and subsequent recovery sleep in healthy young men. Methods After two baseline (BL) nights of 8 h time in bed (TIB), TIB was restricted to 4 h per night for five nights (sleep restriction, SR, n = 15), followed by three recovery nights (REC) of 8 h TIB, representing a busy workweek and a recovery weekend. The control group (n = 8) had 8 h TIB throughout the experiment. A variety of autonomic cardiovascular parameters, together with salivary neuropeptide Y (NPY) and cortisol levels, were assessed. Results In the control group, none of the parameters changed. In the experimental group, heart rate increased from 60 +/- 1.8 beats per minute (bpm) at BL, to 63 +/- 1.1 bpm after SR and further to 65 +/- 1.8 bpm after REC. In addition, whole day low-frequency to-high frequency (LF/HF) power ratio of heart rate variability increased from 4.6 +/- 0.4 at BL to 6.0 +/- 0.6 after SR. Other parameters, including salivary NPY and cortisol levels, remained unaffected. Conclusions Increased heart rate and LF/HF power ratio are early signs of an increased sympathetic activity after prolonged sleep restriction. To reliably interpret the clinical significance of these early signs of physiological stress, a follow-up study would be needed to evaluate if the stress responses escalate and lead to more unfavourable reactions, such as elevated blood pressure and a subsequent elevated risk for cardiovascular health problems.Peer reviewe
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
Corrigendum to “Home infusion experience in patients with Pompe disease receiving avalglucosidase alfa during three clinical trials” [Molecular Genetics and Metabolism, 143 (2024) 108608] (Molecular Genetics and Metabolism (2024) 143(4), (S109671922400492X), (10.1016/j.ymgme.2024.108608))
\ua9 2024 The Author(s). The authors regret an important typographical error in the results text. The rate of infusion-associated reactions with home infusions vs clinic infusions (0.003 vs. 0.006, respectively) appears correctly in the abstract and Table 3 but was incorrectly entered as 0.006 vs 0.006 in Section 3.4 of the results. The authors apologise for any inconvenience caused
Home infusion experience in patients with Pompe disease receiving avalglucosidase alfa during three clinical trials
\ua9 2024 The AuthorsDuring three previously reported clinical trials of avalglucosidase alfa in patients with Pompe disease, 17 out of 142 participants were considered by the investigators to be appropriate candidates for home infusion. During their respective trials, these participants received a total of 419 avalglucosidase alfa infusions at home under healthcare professional supervision. They were clinically stable with no history of moderate or severe infusion-associated reactions within at least 12 months prior to starting home infusions. As of February 25, 2022, the 15 participants with late-onset Pompe disease (LOPD) had received between 2 and 48 home infusions and the 2 participants with infantile-onset Pompe disease (IOPD) had received 19 and 20 infusions. Adverse events occurred in 8 (53 %) participants with LOPD and neither of the participants with IOPD. Seven participants with LOPD had a total of 15 non-treatment-related, non-serious adverse events. One participant with LOPD experienced infusion-associated reactions of eyelid edema and flushing during the first home infusion; both were non-serious adverse events classified as grade 1 (mild). Home infusion was later resumed for this participant. Among LOPD participants, event rates for home infusions were comparable to those for clinic infusions: overall adverse events (0.028 vs 0.039 participants with events/infusion, respectively) and adverse events classified as infusion-associated reactions (0.003 vs. 0.006, respectively). No medication errors occurred during home infusion. These data suggest that infusion of avalglucosidase alfa at home is feasible and does not compromise safety for patients who have not experienced an infusion-associated reaction during the preceding 12 months of infusions in a clinical setting. Evaluation of real-world experience with avalglucosidase alfa home infusion in countries where it is already approved is ongoing
Cadmium body burden and increased blood pressure in middle-aged American Indians: the Strong Heart Study
Cadmium (Cd) is an environmental pollutant that has been associated with cardiovascular disease in populations, but the relationship of Cd with hypertension has been inconsistent. We studied the association between urinary Cd concentrations, a measure of total body burden, and blood pressure in American Indians, a US population with above national average Cd burden. Urinary Cd was measured using inductively coupled plasma mass spectrometry, and adjusted for urinary creatinine concentration. Among 3714 middle-aged American Indian participants of the Strong Heart Study (mean age 56 years, 41% male, 67% ever-smokers, 23% taking antihypertensive medications), urinary Cd ranged from 0.01 to 78.48 μg g creatinine (geometric mean=0.94 μg g) and it was correlated with smoking pack-year among ever-smokers (r=0.16, P<0.0001). Participants who were smokers were on average light-smokers (mean 10.8 pack-years), and urinary Cd was similarly elevated in light- and never-smokers (geometric means of 0.88 μg g creatinine for both categories). Log-transformed urinary Cd was significantly associated with higher systolic blood pressure in models adjusted for age, sex, geographic area, body mass index, smoking (ever vs never, and cumulative pack-years) and kidney function (mean blood pressure difference by lnCd concentration (β)=1.64, P=0.002). These associations were present among light- and never-smokers (β=2.03, P=0.002, n=2627), although not significant among never-smokers (β=1.22, P=0.18, n=1260). Cd was also associated with diastolic blood pressure among light- and never-smokers (β=0.94, P=0.004). These findings suggest that there is a relationship between Cd body burden and increased blood pressure in American Indians, a population with increased cardiovascular disease risk.This research is supported by the NHLBI HL123677-02 to NF and the NIEHS training grant (ES007141-32) to PB. MTP was supported by the Strategic Action for Research in Health sciences [CP12/03080], which is an initiatives from Carlos III Health Institute Madrid and the Spanish Ministry of Economy and Competitiveness and are co-funded with European Funds for Regional Development (FEDER)
- …
