The mitochondrion is a complex organelle that serves essential roles in energy transduction, ATP production, and a myriad of cellular signaling events. A finely tuned regulatory network orchestrates ...the biogenesis, maintenance, and turnover of mitochondria. The high-capacity mitochondrial system in the heart is regulated in a dynamic way to generate and consume enormous amounts of ATP in order to support the constant pumping function in the context of changing energy demands. This review describes the regulatory circuitry and downstream events involved in mitochondrial biogenesis and its coordination with mitochondrial dynamics in developing and diseased hearts.
Axion dark matter in a 3 − 3 − 1 model Montero, J. C.; Romero Castellanos, Ana R.; Sánchez-Vega, B. L.
Physical review. D,
03/2018, Letnik:
97, Številka:
6
Journal Article
Recenzirano
Odprti dostop
Slightly extending a right-handed neutrino version of the 3−3−1 model, we show that it is not only possible to solve the strong CP problem but also to give the total dark matter abundance reported by ...the Planck collaboration. Specifically, we consider the possibility of introducing a 3−3−1 scalar singlet to implement a gravity stable Peccei-Quinn mechanism in this model. Remarkably, for allowed regions of the parameter space, the arising axions with masses ma≈meV can both make up the total dark matter relic density through nonthermal production mechanisms and be very close to the region to be explored by the IAXO helioscope.
Significant evidence indicates that the failing heart is energy starved. During the development of heart failure, the capacity of the heart to utilize fatty acids, the chief fuel, is diminished. ...Identification of alternate pathways for myocardial fuel oxidation could unveil novel strategies to treat heart failure.
Quantitative mitochondrial proteomics was used to identify energy metabolic derangements that occur during the development of cardiac hypertrophy and heart failure in well-defined mouse models. As expected, the amounts of proteins involved in fatty acid utilization were downregulated in myocardial samples from the failing heart. Conversely, expression of β-hydroxybutyrate dehydrogenase 1, a key enzyme in the ketone oxidation pathway, was increased in the heart failure samples. Studies of relative oxidation in an isolated heart preparation using ex vivo nuclear magnetic resonance combined with targeted quantitative myocardial metabolomic profiling using mass spectrometry revealed that the hypertrophied and failing heart shifts to oxidizing ketone bodies as a fuel source in the context of reduced capacity to oxidize fatty acids. Distinct myocardial metabolomic signatures of ketone oxidation were identified.
These results indicate that the hypertrophied and failing heart shifts to ketone bodies as a significant fuel source for oxidative ATP production. Specific metabolite biosignatures of in vivo cardiac ketone utilization were identified. Future studies aimed at determining whether this fuel shift is adaptive or maladaptive could unveil new therapeutic strategies for heart failure.
The concentrations of As, Cd, Cu, Pb and Zn were measured in muscle tissue of Coryphaena hippurus captured in the southern Gulf of California to determine inter-annual variations and their relation ...with environmental parameters for the period 2006–2015; additionally, health risk to consumers was assessed according to levels of studied elements and rate of fish consumption in northwest Mexico. During 2014 and 2015 the levels of As, Cd, Cu, and Zn were significantly lower than the rest of the years; in the case of As, it was also significantly lower in 2010. Oceanic Niño Index was negatively correlated with Zn concentrations in fish, while sea surface temperature was negatively correlated with Zn, Pb and Cd concentrations in dolphinfish. The simultaneous occurrence of the analyzed elements in muscle of dolphinfish indicated that health effects on consumers are not likely to occur; nevertheless, fishermen with elevated fish consumption might be at risk.
•Levels of Cd, Cu, and Zn were significantly lower during 2014 and 2015.•Cu correlated negatively with fork length and weight of fish.•Zn in fish correlated negatively with Oceanic Niño Index.•Hazard quotients for As and Cd were more elevated than the rest of the elements.
We propose an extension of the Standard Model (SM) based on the SU(3)C ⊗ SU(3)L ⊗ U(1)X (3-3-1) gauge symmetry and scale invariance. Maintaining the main features of the so-called 3-3-1 models, such ...as the cancellation of gauge anomalies related to the number of chiral fermion generations, this model exhibits a very compact scalar sector. Only two scalar triplets and one singlet are necessary and sufficient to break the symmetries dynamically via the Coleman-Weinberg mechanism. With the introduction of an Abelian discrete symmetry and assuming a natural hierarchy among the vacuum expectation values of the neutral scalar fields, we show that all particles in the model can get phenomenologically consistent masses. In particular, most of the standard fermion masses are generated via a seesaw mechanism involving some extra heavy fermions introduced for consistency. This mechanism provides a partial solution for the fermion mass hierarchy problem in the SM. Furthermore, the simplicity of the scalar sector allows us to analytically find the conditions for the potential stability up to one-loop level and show how they can be easily satisfied. Some of the new particles, such as the scalars H, H± and all the non-SM vector bosons, are predicted to get masses around the TeV scale and, therefore, could be produced at the high-luminosity LHC. Finally, we show that the model features a residual symmetry, which leads to the stability of a heavy neutral particle; the latter is expected to show up in experiments as missing energy.
A
bstract
The
μτ
-reflection symmetry is a simple symmetry capable of predicting all the unknown CP phases of the lepton sector and the atmospheric angle but too simple to predict the absolute ...neutrino mass scale or the mass ordering. We show that by combining it with a discrete abelian symmetry in a nontrivial way we can additionally enforce a texture-zero and obtain a highly predictive scenario where the lightest neutrino mass is fixed to be in the few meV range for two normal ordering (NO) solutions or in the tens of meV in one inverted ordering (IO) solution. The rate for neutrinoless double beta decay is predicted to be negligible for NO or have effective mass
m
ββ
≈ 14-29 meV for IO, right in the region to be probed in future experiments.
In this work we present a common framework for neutrino masses and dark matter. Specifically, we work with a local B - L extension of the standard model which has three right-handed neutrinos, n(Ri), ...and some extra scalars, Phi, phi(i), besides the standard model fields. The n(Ri)'s have nonstandard B - L quantum numbers and thus these couple to different scalars. This model has the attractive property that an almost automatic Z(2) symmetry acting only on a fermionic field, n(R3), is present. Taking advantage of this Z(2) symmetry, we study both the neutrino mass generation via a natural seesaw mechanism at low energy and the possibility of n(R3) being a dark matter candidate. For this last purpose, we study its relic abundance and its compatibility with the current direct detection experiments.
We present a framework linking axionlike particles (ALPs) to neutrino masses through the minimal inverse seesaw (ISS) mechanism in order to explain the dark matter (DM) puzzle. Specifically, we ...explore three minimal ISS cases where mass scales are generated through gravity-induced operators involving a scalar field hosting ALPs. In all of these cases, we find gravity-stable models that provide the observed DM relic density and, simultaneously, are consistent with the phenomenology of neutrinos and ALPs. Remarkably, in one of the ISS cases, the DM can be made of ALPs and sterile neutrinos. Furthermore, other considered ISS cases have ALPs with parameters that are within the reach of proposed ALP experiments.
In the framework of a 3-3-1 model with right-handed neutrinos and three scalar triplets we consider different spontaneous symmetry breaking patterns seeking for a non-linear realization of accidental ...symmetries of the model, which will produce physical Nambu–Goldstone (NG) bosons in the neutral scalar spectrum. We make a detailed study of the safety of the model concerning the NG boson emission in energy-loss processes which could affect the standard evolution of astrophysical objects. We consider the model with a
Z
2
symmetry, conventionally used in the literature, finding that in all of the symmetry breaking patterns the model is excluded. Additionally, looking for solutions for that problem, we introduce soft
Z
2
-breaking terms in the scalar potential in order to remove the extra accidental symmetries and at the same time maintain the model as simple as possible. We find that there is only one soft
Z
2
-breaking term that enables us to get rid of the problematic NG bosons.
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