The fuzzy 4-hyperboloid Hn4H^4_n and higher-spin in Yang-Mills matrix models

We consider the $SO(4,1)$-covariant fuzzy hyperboloid $H^4_n$ as a solution of Yang-Mills matrix models, and study the resulting higher-spin gauge theory. The degrees of freedom can be identified with functions on classical $H^4$ taking values in a higher-spin algebra associated to $\mathfrak{so}(4,1)$, truncated at spin $n$. We develop a suitable calculus to classify the higher-spin modes, and show that the tangential modes are stable. The metric fluctuations encode one of the spin 2 modes, however they do not propagate in the classical matrix model. Gravity is argued to arise upon taking into account induced gravity terms. This formalism can be applied to the cosmological FLRW space-time solutions of [1], which arise as projections of $H^4_n$. We establish a one-to-one correspondence between the tangential fluctuations of these spaces.Comment: V2: 51+ 17 pages, 1 figure, minor corrections, accepted in Nucl.Phys.

Intersecting branes, Higgs sector, and chirality from N=4\mathcal{N}=4 SYM with soft SUSY breaking

We consider $SU(N)$ $\mathcal{N}=4$ super Yang-Mills with cubic and quadratic soft SUSY breaking potential, such that the global $SU(4)_R$ is broken to $SU(3)$ or further. As shown recently, this set-up supports a rich set of non-trivial vacua with the geometry of self-intersecting $SU(3)$ branes in 6 extra dimensions. The zero modes on these branes can be interpreted as 3 generations of bosonic and chiral fermionic strings connecting the branes at their intersections. Here, we uncover a large class of exact solutions consisting of branes connected by Higgs condensates, leading to Yukawa couplings between the chiral fermionic zero modes. Under certain decoupling conditions, the backreaction of the Higgs on the branes vanishes exactly. The resulting physics is that of a spontaneously broken chiral gauge theory on branes with fluxes. In particular, we identify combined brane plus Higgs configurations which lead to gauge fields that couple to chiral fermions at low energy. This turns out to be quite close to the Standard Model and its constructions via branes in string theory. As a by-product, we construct a $G_2$-brane solution corresponding to a squashed fuzzy coadjoint orbit of $G_2$.Comment: v2: 56 pages,2 appendices, 34 figures, typos corrected, matches JHEP versio

Resting state functional connectivity in early blind humans

Task-based neuroimaging studies in early blind humans (EB) have demonstrated heightened visual cortex responses to non-visual paradigms. Several prior functional connectivity studies in EB have shown altered connections consistent with these task-based results. But these studies generally did not consider behavioral adaptations to lifelong blindness typically observed in EB. Enhanced cognitive abilities shown in EB include greater serial recall and attention to memory. Here, we address the question of the extent to which brain intrinsic activity in EB reflects such adaptations. We performed a resting-state functional magnetic resonance imaging study contrasting 14 EB with 14 age/gender matched normally sighted controls (NS). A principal finding was markedly greater functional connectivity in EB between visual cortex and regions typically associated with memory and cognitive control of attention. In contrast, correlations between visual cortex and non-deprived sensory cortices were significantly lower in EB. Thus, the available data, including that obtained in prior task-based and resting state fMRI studies, as well as the present results, indicate that visual cortex in EB becomes more heavily incorporated into functional systems instantiating episodic recall and attention to non-visual events. Moreover, EB appear to show a reduction in interactions between visual and non-deprived sensory cortices, possibly reflecting suppression of inter-sensory distracting activity

Association of Novel and Highly Diverse Acid-Tolerant Denitrifiers with N2O Fluxes of an Acidic Fen

Wetlands are sources of denitriflcation-derived nitrous oxide (N 2O). Thus, the denitrifler community of an N2O-emitting fen (pH 4.7 to 5.2) was investigated. N2O was produced and consumed to subatmospheric concentrations in unsupplemented anoxic soil microcosms. Total cell counts and most probable numbers of denitriflers approximated 10 11 cells · gDW-1 (where DW is dry weight) and 108 cells • gDW-1, respectively, in both 0- to 10-cm and 30- to 40-cm depths. Despite this uniformity, depth-related maximum reaction rate (vma-) values for denitriflcation in anoxic microcosms ranged from 1 to 24 and - 19 to - 105 nmol N2O h-1 • gDW-1, with maximal values occurring in the upper soil layers. Denitriflcation was enhanced by substrates that might be formed via fermentation in anoxic microzones of soil. N2O approximated 40% of total nitrogenous gases produced at in situ pH, which was likewise the optimal pH for denitriflcation. Gene libraries of narG and nosZ (encoding nitrate reductase and nitrous oxide reductase, respectively) from fen soil DNA yielded 15 and 18 species-level operational taxonomie units, respectively, many of which displayed phylogenetic novelty and were not closely related to cultured organisms. Although statistical analyses of narG and nosZ sequences indicated that the upper 20 cm of soil contained the highest denitrifler diversity and species richness, terminal restriction fragment length polymorphism analyses of narG and nosZ revealed only minor differences in denitrifler community composition from a soil depth of 0 to 40 cm. The collective data indicate that the regional fen harbors novel, highly diverse, acid-tolerant denitrifler communities capable of complete denitriflcation and consumption of atmospheric N2O at in situ pH. Copyright © 2010, American Society for Microbiology. All Rights Reserved

A polyclad turbellarian from oysters in the Gulf of California

Muitos platielmintes da cavidade inalante de Ostrea angelica no Golfo da California representam uma nova especie, Zygantroplana ups, spec. nov

Genome-Derived Criteria for Assigning Environmental narG and nosZ Sequences to Operational Taxonomic Units of Nitrate Reducers

Ninety percent of cultured bacterial nitrate reducers with a 16S rRNA gene similarity of ≥97% had a narG or nosZ similarity of ≥67% or ≥80%, respectively, suggesting that 67% and 80% could be used as standardized, conservative threshold similarity values for narG and nosZ, respectively (i.e., any two sequences that are less similar than the threshold similarity value have a very high probability of belonging to different species), for estimating species-level operational taxonomic units. Genus-level tree topologies of narG and nosZ were generally similar to those of the corresponding 16S rRNA genes. Although some genomes contained multiple copies of narG, recent horizontal gene transfer of narG was not apparent. Copyright © 2009, American Society for Microbiology. All Rights Reserved

Emitter Location by a Time Difference Hyperbolic Net

Electrical Engineerin

Central role of carotid body chemoreceptors in disordered breathing and cardiorenal dysfunction in chronic heart failure.

Oscillatory breathing (OB) patterns are observed in pre-term infants, patients with cardio-renal impairment, and in otherwise healthy humans exposed to high altitude. Enhanced carotid body (CB) chemoreflex sensitivity is common to all of these populations and is thought to contribute to these abnormal patterns by destabilizing the respiratory control system. OB patterns in chronic heart failure (CHF) patients are associated with greater levels of tonic and chemoreflex-evoked sympathetic nerve activity (SNA), which is associated with greater morbidity and poor prognosis. Enhanced chemoreflex drive may contribute to tonic elevations in SNA by strengthening the relationship between respiratory and sympathetic neural outflow. Elimination of CB afferents in experimental models of CHF has been shown to reduce OB, respiratory-sympathetic coupling, and renal SNA, and to improve autonomic balance in the heart. The CB chemoreceptors may play an important role in progression of CHF by contributing to respiratory instability and OB, which in turn further exacerbates tonic and chemoreflex-evoked increases in SNA to the heart and kidney