The Quark-Mass Dependence of Two-Nucleon Systems

We explore the quark-mass dependence of two-nucleon systems. Allowed regions for the scattering lengths in the 1S0 and 3S1 channels as functions of the light-quark masses are determined from the current uncertainty in strong-interaction parameters that appear at next-to-leading order in the effective field theory. Where experimental constraints are absent, as is the case for the quark-mass dependent four-nucleon operators, we use naive dimensional analysis. We find it likely that there is no bound state in the 1S0 channel in the chiral limit. However, given the present uncertainties in strong-interaction parameters it is unclear whether the deuteron is bound or unbound in the chiral limit.Comment: 12 pages LaTeX, 6 ps figs, comments adde

Variation of Fundamental Couplings and Nuclear Forces

The dependence of the nuclear force on standard model parameters plays an important role in bounding time and space variations of fundamental couplings over cosmological time scales. We discuss the quark-mass dependence of deuteron and di-neutron binding in a systematic chiral expansion. The leading quark-mass dependence of the nuclear force arises from one-pion exchange and from local quark-mass dependent four-nucleon operators with coefficients that are presently unknown. By varying these coefficients while leaving nuclear observables at the physical values of the quark masses invariant, we find scenarios where two-nucleon physics depends both weakly and strongly on the quark masses. While the determination of these coefficients is an exciting future opportunity for lattice QCD, we conclude that, at present, bounds on time and space variations of fundamental parameters from the two-nucleon sector are much weaker than previously claimed. This brings into question the reliability of coupling-constant bounds derived from more complex nuclei and nuclear processes.Comment: 16 pages LaTeX, 4 eps figs, 12 ps fig

Systematic Literature Review on the LDAP Protocol As a Centralized Mechanism for the Authentication of Users in Multiple Systems

The protocol LDAP (Lightweight Directory Access Protocol) allows centralized identity authentication, where the information of the directory is faster and easier to read. This article carries out a systematic literature review (SLR) according to what is proposed in the article by Bárbara Kitchenham [1], aimed to identify different methods for users’ authentication in multiple systems using LDAP protocol, an analysis of criteria is carried out about different studies published in five digital libraries (Scopus, IEEEXplorer, Scientific.net, Google Scholar, DBLP), and two academic magazines (Revista Energía of UNL, Revista Científica of UTB), making relevant conclusions of the use of four mechanisms for the authentication of users of multiple systems such as: Languaje PHP, SSO (Single sign-on), IAM (Identity and Access Management), and T-RBAC (Access control based on roles and tasks), predominantly the use of the PHP language for its administrative tools for managing LDAP servers.     Keywords: LDAP, authentication, user management, systematic literature review, securit

Correction: Ordoñez, et al.; DNA methylation of enhancer elements in myeloid neoplasms: think outside the promoters? Cancers 2019, 11, 1424

The authors would like to make a correction to their published pape

On the Rollout of Network Slicing in Carrier Networks: A Technology Radar

Network slicing is a powerful paradigm for network operators to support use cases with widely diverse requirements atop a common infrastructure. As 5G standards are completed, and commercial solutions mature, operators need to start thinking about how to integrate network slicing capabilities in their assets, so that customer-facing solutions can be made available in their portfolio. This integration is, however, not an easy task, due to the heterogeneity of assets that typically exist in carrier networks. In this regard, 5G commercial networks may consist of a number of domains, each with a different technological pace, and built out of products from multiple vendors, including legacy network devices and functions. These multi-technology, multi-vendor and brownfield features constitute a challenge for the operator, which is required to deploy and operate slices across all these domains in order to satisfy the end-to-end nature of the services hosted by these slices. In this context, the only realistic option for operators is to introduce slicing capabilities progressively, following a phased approach in their roll-out. The purpose of this paper is to precisely help designing this kind of plan, by means of a technology radar. The radar identifies a set of solutions enabling network slicing on the individual domains, and classifies these solutions into four rings, each corresponding to a different timeline: (i) as-is ring, covering today’s slicing solutions; (ii) deploy ring, corresponding to solutions available in the short term; (iii) test ring, considering medium-term solutions; and (iv) explore ring, with solutions expected in the long run. This classification is done based on the technical availability of the solutions, together with the foreseen market demands. The value of this radar lies in its ability to provide a complete view of the slicing landscape with one single snapshot, by linking solutions to information that operators may use for decision making in their individual go-to-market strategies.H2020 European Projects 5G-VINNI (grant agreement No. 815279) and 5G-CLARITY (grant agreement No. 871428)Spanish national project TRUE-5G (PID2019-108713RB-C53

Loss of genes implicated in gastric function during platypus evolution

Several genes implicated in food digestion have been deleted or inactivated in platypus. This loss perhaps explains the anatomical and physiological differences in the gastrointestinal tract between monotremes and other vertebrates and provides insights into platypus genome evolution

Pions in the Pionless Effective Field Theory

We show that processes involving pions that remain very near their mass-shell can be reliably computed in the pionless effective field theory, with the pion integrated in as a heavy field. As an application, we compute the pion-deuteron scattering amplitude near threshold to next-to-leading order in the momentum expansion. This amplitude is formally dominated by an infrared logarithm of the form log(gamma/mpi), where gamma is the deuteron binding momentum, and mpi is the mass of the pion. The coefficient of this logarithm is determined by the S-wave pion-nucleon scattering lengths.Comment: 10 pages LaTeX, 4 eps fig

Analyzing Explosive Volcanic Deposits From Satellite‐Based Radar Backscatter, Volcán de Fuego, 2018

Satellite radar backscatter has the potential to provide useful information about the progression of volcanic eruptions when optical, ground-based, or radar phase-based measurements are limited. However, backscatter changes are complex and challenging to interpret: explosive deposits produce different signals depending on pre-existing ground cover, radar parameters and eruption characteristics. We use high temporal- and spatial-resolution backscatter imagery to examine the emplacement and alteration of pyroclastic density currents (PDCs), lahar and ash deposits from the June 2018 eruption of Volcán de Fuego, Guatemala, using observatory reports and rainfall gauge data to ground truth our observations. We use a temporally dense time series of backscatter data to reduce noise and extract deposit areas. We observe backscatter changes in six drainages, the largest deposit was 11.9-km-long that altered an area of 6.3 urn:x-wiley:21699313:media:jgrb55183:jgrb55183-math-0001 and had a thickness of 10.5 urn:x-wiley:21699313:media:jgrb55183:jgrb55183-math-00022 m in the lower sections as estimated from radar shadows. The 3 June eruption also produced backscatter signal over an area of 40 urn:x-wiley:21699313:media:jgrb55183:jgrb55183-math-0003, consistent with reported ashfall. We use transient patterns in backscatter time series to identify nine periods of high lahar activity in a single drainage system between June and October 2018. We find that the characterisation of subtle backscatter signals associated with explosive eruptions are best observed with (1) radiometric terrain calibration, (2) speckle correction, and (3) consideration of pre-existing scattering properties. Our observations demonstrate that SAR backscatter can capture the emplacement and subsequent alteration of a range of explosive deposits, allowing the progression of an explosive eruption to be monitored

Valor nutricional de forraje de Pízamo (Erythrina glauca) ensilado con diferentes niveles de melaza y harina de arroz

This investigation evaluated the silage of Erythrina glauca forage in its nutritional quality, to be used later on in the animal feeding of in Colombia. The Erythrina glauca silage, was pack in silage bag was added to forage three levels of molasses (10%, 15% and 20%), besides, was added 3% of flour of rice by treatment, being the other half of the forage without flour, the silaje, was analyzed in four times of maturation: 0, 30, 60 y 90 days; with three repetitions each one. The trial was randomized completely to the chance with a factorial arrangement of 3x4x2, being respectively for treatments, and times of maduration and addition of flour of rice: It was used variance analysis and test of Tukey. The evaluated variables were: Dry matter, protein, raw fiber, fat, non-nitrogenaus extract, ash, the fiber in the neuter detergent (NFD), fiber in the acid detergent (AFD) and degradation in the rumen of the dry matter (DDM). The content of matter of the silage increased (P<0.05) when the levels of molasses were increased and flour of rice was added, while the time of maturation did not influence (P>0.05) on the DM content. The protein content decreased (P<0.05) as it increases the time of maturation, but it is increased (P<0.05) when flour of rice is added. The raw fiber, the NFD and the AFD decreased (P<0.05) as the time of maturation was increased. The opposite happened to the DDM at the 72 hours, which was increased (P<0.05) as it increased the time of maturation. The DDM in the different hours of degradation was minimum, being observed an alike result (P>0.05) in each one of the evaluated hours (6, 12, 24, 48 and 72) The DDM was quick in the first 6 hours, until 39%. The increment in the following hours was: 2%, 8%, 11% and 13,7%, respectively, that which indicated that the degradation was slow after the 6 hours until the 72 hours, the fat and ashy didn't affect any treatment. Was concluded that the raw fiber, the NFD, AFD were affected the fermentation of the microorganisms, since they break the cellular walls, causing a decrease, that which allows a bigger degradation in the rumen.El objetivo de esta de investigación fue evaluar el ensilaje de forraje de Pízamo (Erythrina glauca) en su calidad nutricional, para ser utilizado posteriormente en la alimentación animal de en el Piedemonte Llanero de Colombia. Se preparó ensilaje de forraje de Pízamo, en silo-bolsa con tres niveles de melaza: 10%, 15% y 20%, se tomó la mitad del material picado al cual se le había aplicado los diferentes niveles de melaza y se le adicionó un 3% de harina de arroz por tratamiento, quedando la otra mitad del material sin harina, conformando así las diferentes alternativas del ensilaje, para ser analizados en cuatro tiempos de maduración: inicial, treinta, sesenta y noventa días; con tres repeticiones cada uno; conformando un diseño experimental completamente al azar con un arreglo factorial de 3X4X2, siendo respectivamente para tratamientos, tiempos y adición de harina de arroz: Se utilizó análisis de varianza y prueba de Tukey. Las variables evaluadas fueron: Materia seca, proteína, fibra cruda, grasa, extracto no nitrógenado (ENN), cenizas, fibra detergente neutro (FDN), fibra detergente ácido (FDA) y degradabilidad ruminal de la materia seca (DMS). El contenido de materia del ensilaje se aumentó (P<0.05) cuando se incrementaron los niveles de melaza y se adicionó harina de arroz, mientras que el tiempo de maduración no influyó (P>0.05) en el contenido de MS. El contenido de proteína se disminuye (P<0.05) a medida que aumenta el tiempo de maduración, pero se incrementa (P<0.05) cuando se adiciona harina de arroz. La fibra cruda, la FDN y la FDA se disminuyeron (P<0.05) a medida que se incrementaba el tiempo de maduración. Lo contrario sucedió con la DMS a las 72 horas, la cual se fue incrementado (P<0.05) a medida que se aumentaba el tiempo de maduración. La DMS en las diferentes horas de degradación fue mínima, observándose un comportamiento similar (P>0.05) en cada una de las horas evaluadas (6, 12, 24, 48 y 72). La DMS fue rápida en las primeras 6 horas, llegando a un 39%, promedio de todos los tratamientos, el incremento en las siguientes horas fue: 2%, 8%, 11% y 13, 7%, respectivamente, lo cual indica que la degradación fue lenta después de las 6 horas hasta las 72 horas. El contenido de grasa y cenizas no se afectó con ningún tratamiento. Se puede concluir que la fibra cruda, la FDN, FDA se afectan con la fermentación de los microorganismos, puesto que rompen las paredes celulares, ocasionando una disminución, lo cual permite una mayor degradabilidad en el rumen