2,778 research outputs found
The Radio Jet Associated with the Multiple V380 Ori System
The giant Herbig-Haro object 222 extends over 6 in the plane of the
sky, with a bow shock morphology. The identification of its exciting source has
remained uncertain over the years. A non-thermal radio source located at the
core of the shock structure was proposed to be the exciting source. However,
Very Large Array studies showed that the radio source has a clear morphology of
radio galaxy and a lack of flux variations or proper motions, favoring an
extragalactic origin. Recently, an optical-IR study proposed that this giant HH
object is driven by the multiple stellar system V380 Ori, located about 23
to the SE of HH 222. The exciting sources of HH systems are usually detected as
weak free-free emitters at centimeter wavelengths. Here we report the detection
of an elongated radio source associated with the Herbig Be star or with its
close infrared companion in the multiple V380 Ori system. This radio source has
the characteristics of a thermal radio jet and is aligned with the direction of
the giant outflow defined by HH~222 and its suggested counterpart to the SE,
HH~1041. We propose that this radio jet traces the origin of the large scale HH
outflow. Assuming that the jet arises from the Herbig Be star, the radio
luminosity is a few times smaller than the value expected from the
radio-bolometric correlation for radio jets, confirming that this is a more
evolved object than those used to establish the correlation.Comment: 13 pages, 3 figure
Ubiquitin plays an atypical role in GPCR-induced p38 MAP kinase activation on endosomes.
Protease-activated receptor 1 (PAR1) is a G protein-coupled receptor (GPCR) for thrombin and promotes inflammatory responses through multiple pathways including p38 mitogen-activated protein kinase signaling. The mechanisms that govern PAR1-induced p38 activation remain unclear. Here, we define an atypical ubiquitin-dependent pathway for p38 activation used by PAR1 that regulates endothelial barrier permeability. Activated PAR1 K63-linked ubiquitination is mediated by the NEDD4-2 E3 ubiquitin ligase and initiated recruitment of transforming growth factor-β-activated protein kinase-1 binding protein-2 (TAB2). The ubiquitin-binding domain of TAB2 was essential for recruitment to PAR1-containing endosomes. TAB2 associated with TAB1, which induced p38 activation independent of MKK3 and MKK6. The P2Y1 purinergic GPCR also stimulated p38 activation via NEDD4-2-mediated ubiquitination and TAB1-TAB2. TAB1-TAB2-dependent p38 activation was critical for PAR1-promoted endothelial barrier permeability in vitro, and p38 signaling was required for PAR1-induced vascular leakage in vivo. These studies define an atypical ubiquitin-mediated signaling pathway used by a subset of GPCRs that regulates endosomal p38 signaling and endothelial barrier disruption
The Non-thermal Radio Jet Toward the NGC 2264 Star Formation Region
We report sensitive VLA 3.6 cm radio observations toward the head of the Cone
nebula in NGC 2264, made in 2006. The purpose of these observations was to
study a non-thermal radio jet recently discovered, that appears to emanate from
the head of the Cone nebula. The jet is highly polarized, with well-defined
knots, and one-sided. The comparison of our images with 1995 archive data
indicates no evidence of proper motions nor polarization changes. We find
reliable flux density variations in only one knot, which we tentatively
identify as the core of a quasar or radio galaxy. An extragalactic location
seems to be the best explanation for this jet.Comment: 12 pages, 5 figure
Surface morphologies of Ti and Ti-Al-V bombarded by 1.0-MeV Au+ Ions
Ion implantation is known to enhance the mechanical properties of biomaterials such as, e.g., the wear resistance of orthopedic joints. Increasing the surface area of implants may likewise improve their integration with, e.g., bone tissue, which requires surface features with sizes in the micron range. Ion implantation of biocompatible metals has recently been demonstrated to induce surface ripples with wavelengths of a few microns. However, the physical mechanisms controlling the formation and characteristics of these patterns are yet to be understood. We bombard Ti and Ti-6Al-4V surfaces with 1.0-MeV Au+ ions. Analysis by scanning electron and atomic force microscopies shows the formation of surface ripples with typical dimensions in the micron range, with potential indeed for biomedical applications. Under the present specific experimental conditions, the ripple properties are seen to strongly depend on the fluence of the implanted ions while being weakly dependent on the target material. Moreover, by examining experiments performed for incidence angle values theta = 8 degrees, 23 degrees, 49 degrees, and 67 degrees, we confirm the existence of a threshold incidence angle for (ripple) pattern formation. Surface indentation is also used to study surface features under additional values of., agreeing with our single-angle experiments.This work was financially supported by Dirección General de Asuntos del Personal
Académico-UNAM under Contracts No. Programa de
Apoyo a Proyectos de Investigación e Innovación Tecnológica IN110116 and No. IN111717, and by
CONACYT under Contract No. 222485. L. R. d. l. V. is
supported by the Programa de Estancias Sabáticas
Nacionales del Consejo Nacional de Ciencia y
TecnologÃa (CONACyT). R. C. acknowledges the kind
hospitality and support of the Instituto de FÃsica at
UNAM while part of this work was being carried out, as
well as partial support from Ministerio de EconomÃa y
Competitividad/Fondo Europeo de Desarrollo Regional
(Spain/European Union) through Grants No. FIS2012-
38866-C05-01 and No. FIS2015-66020-C2-1-P
The biodiversity of freshwater Crustaceans revealed by taxonomy and mitochondrial DNA barcodes
Cytochrome oxidase subunit I (COI) barcode sequences in this file were obtained from specimens collected by plankton net in western Lake Erie in 2012 & 2013, along with later specimens collected at various locations and times, including some collected in Belize in 2015. Methods and other details about these sequences are described in a paper by the same authors in a submitted publication (2021: URL to be given here when published). The right columns below contain additional notes on lengths of sequences, GenBank accession ID (when obtained), and annotation as to whether the sequence represents a new barcode for its genus or species taxon. According to our experience, a DNA identity of \u3e96.5% with previous GenBank barcodes is a reliable range for determining a species level barcode for that morpho species; a DNA identity of 90.5% to 96.5% with previous barcodes is sufficient to identify genus. DNA identities within these ranges are considered to be barcode confirmations. Conversely, DNA identities outside of these ranges are considered to be new barcodes for that species or genus, respectively. Contradictions with previous GenBank sequences are discussed in the manuscript. The submitted manuscript includes the highest percentage identity to a previous sequence in GenBank as determined by BLASTN in June2021. The FASTA file name given here begins with a Ram Lab ID number-location and date of collection with format varying somewhat between various collections/collectors but generally including several (usually three) location letters (e.g., BHL stands for Blue Heron Lagoon) and the date usually in a 6-character format of MMDDYY, and optionally a sample number for that date either preceding the location letters or following the date. Collection location abbreviations include the following: All sequences starting with PM, Toledo Harbor in western Lake Erie; LMUSK, Lake Muskoday, Belle Isle, Detroit; SCL, Saint Clair River; BHL, Blue Heron Lagoon, Belle Isle; LE, LakeErie; LSC, Lake St.Clair; MMLE; Metzgers Marsh, LakeErie; MM, Metzgers Marsh; LP, Leonard Preserve, Manchester, Michigan; HR, Huron River Drive, Ypsilanti, Michigan; LCL, Little Cedar Lake, Orion, MI; HLE, Harbor Lake Erie; LHLE, Lorain Harbor Lake Erie; BZEB1P, Cenote in Shipstern Reserve, Corozal, Belize, Central America
Ewe Daily-Weight Gain Grazing \u3ci\u3eLeucaena leucocephala-Megathyrsus maximus\u3c/i\u3e CV Mombasa Silvopastoral System and Tropical Native Unimproved Range
Silvopastoral systems are a viable option to increase livestock productivity, The silvopastoral arrangement of Leucaena leucocephala associated with Megathyrsus maximus CV Mombasa (LMS) is successfully cultivated in tropical environments.. The objective of the study was to determine ewe daily-weight gain grazing LMS and a tropical unimproved native range. Two LMS were tested: high and low leucaena densities, 4700 and 2383 plants/ha, respectively. Grazing was rotational, lasted 150 d (rainy season) at equivalent stocking rate of 59 ewes/ha/150 d. Experimental design was a completely random design with three replications, the experimental unit was a 192 m2 plot. Variables measured on plots were amount (dry matter basis), in vitro dry matter digestibility (IVDMD), and crude protein (CP) of forage on-offer, from mixed samples herbaceous and tree fodder. Weight and serum concentrations of Ca, P, K, Mg, Na, Zn, Cu, and Fe were measured in ewes, daily weight gain was calculated. On average forage on-offer and IVDMD concentration were 50 and 15% higher (p \u3c 0.05) in LMS than in native range, respectively, with no difference between LMS. CP concentration was 25% higher (p \u3c 0.05) in native range than both LMS, with no difference between them. LMS’s showed no difference (p \u3e 0.05) between them on ewe daily weight gain, on average 59.2 g, and were higher than native range where ewes showed a mean daily weight loss of 14.8 g. Serum concentrations of the 8 minerals measured were similar (p \u3e 0.05) across all ewes regardless the treatments. It was concluded that the Leucaena leucocephala-Megathyrsus maximus CV Mombasa silvopastoral system is an option to improve livestock productivity compared with unimproved native range due to higher forage on-offer
Ewe Daily-Weight Gain Grazing \u3ci\u3eLeucaena leucocephala-Megathyrsus maximus\u3c/i\u3e CV Mombasa Silvopastoral System and Tropical Native Unimproved Range
Silvopastoral systems are a viable option to increase livestock productivity, The silvopastoral arrangement of Leucaena leucocephala associated with Megathyrsus maximus CV Mombasa (LMS) is successfully cultivated in tropical environments.. The objective of the study was to determine ewe daily-weight gain grazing LMS and a tropical unimproved native range. Two LMS were tested: high and low leucaena densities, 4700 and 2383 plants/ha, respectively. Grazing was rotational, lasted 150 d (rainy season) at equivalent stocking rate of 59 ewes/ha/150 d. Experimental design was a completely random design with three replications, the experimental unit was a 192 m2 plot. Variables measured on plots were amount (dry matter basis), in vitro dry matter digestibility (IVDMD), and crude protein (CP) of forage on-offer, from mixed samples herbaceous and tree fodder. Weight and serum concentrations of Ca, P, K, Mg, Na, Zn, Cu, and Fe were measured in ewes, daily weight gain was calculated. On average forage on-offer and IVDMD concentration were 50 and 15% higher (p \u3c 0.05) in LMS than in native range, respectively, with no difference between LMS. CP concentration was 25% higher (p \u3c 0.05) in native range than both LMS, with no difference between them. LMS’s showed no difference (p \u3e 0.05) between them on ewe daily weight gain, on average 59.2 g, and were higher than native range where ewes showed a mean daily weight loss of 14.8 g. Serum concentrations of the 8 minerals measured were similar (p \u3e 0.05) across all ewes regardless the treatments. It was concluded that the Leucaena leucocephala-Megathyrsus maximus CV Mombasa silvopastoral system is an option to improve livestock productivity compared with unimproved native range due to higher forage on-offer
Defects and boundary layers in non-Euclidean plates
We investigate the behavior of non-Euclidean plates with constant negative
Gaussian curvature using the F\"oppl-von K\'arm\'an reduced theory of
elasticity. Motivated by recent experimental results, we focus on annuli with a
periodic profile. We prove rigorous upper and lower bounds for the elastic
energy that scales like the thickness squared. In particular we show that are
only two types of global minimizers -- deformations that remain flat and saddle
shaped deformations with isolated regions of stretching near the edge of the
annulus. We also show that there exist local minimizers with a periodic profile
that have additional boundary layers near their lines of inflection. These
additional boundary layers are a new phenomenon in thin elastic sheets and are
necessary to regularize jump discontinuities in the azimuthal curvature across
lines of inflection. We rigorously derive scaling laws for the width of these
boundary layers as a function of the thickness of the sheet
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