13,546 research outputs found
TAXOMETRICS CLASSIFICATION (HIERARCHICAL AND ORDINATION) OF AQUATIC AND SEMI-AQUATIC MOSSES: A PRELIMINARY MODEL TO BRYODIVERSITY MANAGEMENT
Bryodiversity is naturally serving the ecosystems sustainably. It serves the environments by preventing natural disaster (flooding), maintaining the quality of the water body and filter or treats the pollutants naturally. Efficient bryodiversity management is needed for environmental cost cutting and have a cost-effective management strategy. To achieve this, cluster and principal component analyses (PCA) were manipulated to produce the linkage distance between the OTUs and identify the important groups of characters, respectively. In return, it becomes a guideline for bryoflora and environmental managements. In this study, 23 OTUs and 156 characters were analyzed. The output from the reliability and item analysis showed that the data set is highly reliable (Cronbach’s alpha = 0.9627). From the cluster analysis, it showed that 5 clustered groups (manageable units) could be derived from the produced phenogram. This is based on the nearest neighbour amalgation rule and Euclidean distances. As for the principal component analysis, three factors were derived and explained 75.1064% of the variation with 56.0485%(PC1), 11.7346%(PC2) and 7.3233%(PC3), respectively. The ordination showed that 5 manageable units were derived from PC1 and 3 manageable units for PC2 and PC3, respectively. In conclusion, conservation should precede any biodiversity management plans.  Keywords: aquatic mosses, semi-aquatic mosses, cluster analysis, principal component analysis (PCA), classification Â
Discovery of a wide companion near the deuterium burning mass limit in the Upper Scorpius association
We present the discovery of a companion near the deuterium burning mass limit
located at a very wide distance, at an angular separation of 4.6+/-0.1 arcsec
(projected distance of ~ 670 AU) from UScoCTIO108, a brown dwarf of the very
young Upper Scorpius association. Optical and near-infrared photometry and
spectroscopy confirm the cool nature of both objects, with spectral types of M7
and M9.5, respectively, and that they are bona fide members of the association,
showing low gravity and features of youth. Their masses, estimated from the
comparison of their bolometric luminosities and theoretical models for the age
range of the association, are 60+/-20 and 14^{+2}_{-8} MJup, respectively. The
existence of this object around a brown dwarf at this wide orbit suggests that
the companion is unlikely to have formed in a disk based on current planet
formation models. Because this system is rather weakly bound, they did not
probably form through dynamical ejection of stellar embryos.Comment: 10 pages, including 4 figures and 2 table
Active galactic nuclei synapses: X-ray versus optical classifications using artificial neural networks
(Abridged) Many classes of active galactic nuclei (AGN) have been defined
entirely throughout optical wavelengths while the X-ray spectra have been very
useful to investigate their inner regions. However, optical and X-ray results
show many discrepancies that have not been fully understood yet. The aim of
this paper is to study the "synapses" between the X-ray and optical
classifications.
For the first time, the new EFLUXER task allowed us to analyse broad band
X-ray spectra of emission line nuclei (ELN) without any prior spectral fitting
using artificial neural networks (ANNs). Our sample comprises 162 XMM-Newton/pn
spectra of 90 local ELN in the Palomar sample. It includes starbursts (SB),
transition objects (T2), LINERs (L1.8 and L2), and Seyferts (S1, S1.8, and S2).
The ANNs are 90% efficient at classifying the trained classes S1, S1.8, and
SB. The S1 and S1.8 classes show a wide range of S1- and S1.8-like components.
We suggest that this is related to a large degree of obscuration at X-rays. The
S1, S1.8, S2, L1.8, L2/T2/SB-AGN (SB with indications of AGN), and SB classes
have similar average X-ray spectra within each class, but these average spectra
can be distinguished from class to class. The S2 (L1.8) class is linked to the
S1.8 (S1) class with larger SB-like component than the S1.8 (S1) class. The L2,
T2, and SB-AGN classes conform a class in the X-rays similar to the S2 class
albeit with larger fractions of SB-like component. This SB-like component is
the contribution of the star-formation in the host galaxy, which is large when
the AGN is weak. An AGN-like component seems to be present in the vast majority
of the ELN, attending to the non-negligible fraction of S1-like or S1.8-like
component. This trained ANN could be used to infer optical properties from
X-ray spectra in surveys like eRosita.Comment: 15 pages, 7 figures, accepted for publication in A&A. Appendix B only
in the full version of the paper here:
https://dl.dropboxusercontent.com/u/3484086/AGNSynapsis_OGM_online.pd
Showcasing a Barren Plateau Theory Beyond the Dynamical Lie Algebra
Barren plateaus have emerged as a pivotal challenge for variational quantum
computing. Our understanding of this phenomenon underwent a transformative
shift with the recent introduction of a Lie algebraic theory capable of
explaining most sources of barren plateaus. However, this theory requires
either initial states or observables that lie in the circuit's Lie algebra.
Focusing on parametrized matchgate circuits, in this work we are able to go
beyond this assumption and provide an exact formula for the loss function
variance that is valid for arbitrary input states and measurements. Our results
reveal that new phenomena emerge when the Lie algebra constraint is relaxed.
For instance, we find that the variance does not necessarily vanish inversely
with the Lie algebra's dimension. Instead, this measure of expressiveness is
replaced by a generalized expressiveness quantity: The dimension of the Lie
group modules. By characterizing the operators in these modules as products of
Majorana operators, we can introduce a precise notion of generalized globality
and show that measuring generalized-global operators leads to barren plateaus.
Our work also provides operational meaning to the generalized entanglement as
we connect it with known fermionic entanglement measures, and show that it
satisfies a monogamy relation. Finally, while parameterized matchgate circuits
are not efficiently simulable in general, our results suggest that the
structure allowing for trainability may also lead to classical simulability.Comment: 5+26 pages, 2+1 figure
Parallel-in-time quantum simulation via Page and Wootters quantum time
In the past few decades, researchers have created a veritable zoo of quantum
algorithm by drawing inspiration from classical computing, information theory,
and even from physical phenomena. Here we present quantum algorithms for
parallel-in-time simulations that are inspired by the Page and Wooters
formalism. In this framework, and thus in our algorithms, the classical
time-variable of quantum mechanics is promoted to the quantum realm by
introducing a Hilbert space of "clock" qubits which are then entangled with the
"system" qubits. We show that our algorithms can compute temporal properties
over different times of many-body systems by only using clock
qubits. As such, we achieve an exponential trade-off between time and spatial
complexities. In addition, we rigorously prove that the entanglement created
between the system qubits and the clock qubits has operational meaning, as it
encodes valuable information about the system's dynamics. We also provide a
circuit depth estimation of all the protocols, showing an exponential advantage
in computation times over traditional sequential in time algorithms. In
particular, for the case when the dynamics are determined by the Aubry-Andre
model, we present a hybrid method for which our algorithms have a depth that
only scales as . As a by product we can relate the
previous schemes to the problem of equilibration of an isolated quantum system,
thus indicating that our framework enable a new dimension for studying
dynamical properties of many-body systems.Comment: 19+15 pages, 18+1 figure
Treatment of a Complex Distal Triceps Tendon Rupture With a New Technique: A Case Report
Introduction: The distal triceps tendon rupture is an uncommon injury. The acute treatment is well-defined, but when a delayed diagnosis is made or when a tendon retraction is present the alternatives or reconstruction are limited and sometimes complex.
Case Presentation: In this case, we report on a 28-year-old man who presented with a chronic disruption of the distal triceps tendon with a gap of approximately 15 cm. The patient was diagnosed in another center with an inveterate breakage of the distal triceps tendon and was initially treated with an Achilles allograft that was complicated by a wound infection and required more than ten surgeries. Nearly 22 months after the initial trauma, and 12 months after the first surgery, we performed a reconstruction with an Achilles tendon allograft using the new technique of distal attachment. At the 12-month follow-up the patient presented a joint balance from -5º to 110º and presented with no pain.
Conclusions: The use of an Achilles tendon allograft provides excellent results in complex distal triceps tendon ruptures. We report the use of a new technique to anchor a distal Achilles allograft
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Amphotericin forms an extramembranous and fungicidal sterol sponge.
For over 50 years, amphotericin has remained the powerful but highly toxic last line of defense in treating life-threatening fungal infections in humans with minimal development of microbial resistance. Understanding how this small molecule kills yeast is thus critical for guiding development of derivatives with an improved therapeutic index and other resistance-refractory antimicrobial agents. In the widely accepted ion channel model for its mechanism of cytocidal action, amphotericin forms aggregates inside lipid bilayers that permeabilize and kill cells. In contrast, we report that amphotericin exists primarily in the form of large, extramembranous aggregates that kill yeast by extracting ergosterol from lipid bilayers. These findings reveal that extraction of a polyfunctional lipid underlies the resistance-refractory antimicrobial action of amphotericin and suggests a roadmap for separating its cytocidal and membrane-permeabilizing activities. This new mechanistic understanding is also guiding development of what are to our knowledge the first derivatives of amphotericin that kill yeast but not human cells
Characterization of organic packing materials in the removal of ammonia gas in automated biofilters
A fully-automated pilot-scale biofilter filled with coconut fiber as packing material was investigatedfor treatment of ammonia-containing off-gas streams. Coconut fiber was completely characterized forphysical and chemical parameters and biological activity. Biofilter performance was assessed in a pilot-scale unit in a set of continuous experiments varying the inlet ammonia concentration in a range of 45 to240 ppmv at a gas contact time of 36 seconds. Samples taken along the bed height as well as inlet and outletammonia concentrations were used to determine a maximum elimination capacity of 12 g NH3m?3h?1ata 80% removal efficiency. Some features related to nitrification inhibition encountered in the experimentsare also discussed.Peer ReviewedPostprint (published version
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