225 research outputs found
Educating Future Environmental Health Professionals
Future environmental health problems will require a new generation of educated and trained professionals. Efforts to enhance the environmental public health workforce have been promoted by several organizations. While progress has been measured by these organizations, many environmental health academic programs are experiencing budget reductions and lower enrollments. One of the reasons for this trend is the so-called higher education crisis. We argue that training is not equivalent to education in the environmental health sciences, albeit the two terms are often used interchangeably. Organizations involved with the education, training, and credentialing of environmental health professionals must work together to ensure the viability and effectiveness of environmental health academic programs
The differential effects of low birth weight and Western diet consumption upon early life hepatic fibrosis development in guinea pig
Key points: Postnatal intake of a high saturated fat/high sugar diet, the Western diet (WD), is a risk factor for liver fibrosis. Recently, adverse in utero conditions resulting in low birth weight (LBW) have also been associated with postnatal fibrosis development. We demonstrate that suboptimal in utero conditions resulting in LBW are associated with changes in hepatic profibrotic genes in conjunction with minimal liver fibrosis in young non-overweight adult guinea pigs. Our results also indicate that WD promotes liver steatosis, enhanced expression of hepatic genes and proteins of the proinflammatory, profibrotic, cell death and collagen deposition pathways in conjunction with mild hepatic fibrosis. Our data highlight that pathways responsible for the initiation of a profibrotic state and ultimately hepatic fibrosis appear different depending upon the insult, an in utero-induced LBW outcome or a postnatal WD exposure. Postnatal intake of an energy dense diet, the Western diet (WD), is a strong risk factor for liver fibrosis. Recently, adverse in utero conditions resulting in low birth weight (LBW) have also been associated with postnatal fibrosis development. We assessed the independent and possible synergistic effects of placental insufficiency-induced LBW and postnatal WD consumption on liver fibrosis in early adulthood, with a specific focus on changes in inflammation and apoptosis pathways in association with fibrogenesis. Male LBW (uterine artery ablation) and normal birth weight (NBW) guinea pig pups were fed either a control diet (CD) or WD from weaning to 150 days. Significant steatosis, mild lobular inflammation, apoptosis and mild stage 1 fibrosis (perisinusoidal or portal) were evident in WD-fed offspring (NBW/WD and LBW/WD). In LBW/CD versus NBW/CD offspring, increased transforming growth factor-beta 1 and matrix metallopeptidase mRNA and sma- and Mad-related protein 4 (SMAD4) were present in conjunction with minimal stage 1 portal fibrosis. Further, connective tissue growth factor mRNA was increased and miR-146a expression decreased in LBW offspring, irrespective of diet. Independent of birth weight, WD-fed offspring exhibited increased expression of fibrotic genes as well as elevated inflammatory and apoptotic markers. Moreover, the augmented expression of collagen, type III, alpha 1 and tumor necrosis factor-alpha was associated with increased recruitment of RNA polymerase II and enhanced histone acetylation (K9) to their respective promoters. These data support a role for both LBW and postnatal WD as factors contributing to hepatic fibrosis development in offspring through distinct pathways
Tactile Elevation Perception in Blind and Sighted Participants and Its Implications for Tactile Map Creation
Evidence for orbital ordering in LaCoO3
We present powder and single crystal X-ray diffraction data as evidence for a
monoclinic distortion in the low spin (S=0) and intermediate spin state (S=1)
of LaCoO3. The alternation of short and long bonds in the ab plane indicates
the presence of eg orbital ordering induced by a cooperative Jahn-Teller
distortion. We observe an increase of the Jahn-Teller distortion with
temperature in agreement with a thermally activated behavior of the Co3+ ions
from a low-spin ground state to an intermediate-spin excited state.Comment: Accepted to Phys. Rev.
Novel sources of Flavor Changed Neutral Currents in the model
Sources of Flavor Changed Neutral Currents (FCNC) naturally emerge from a
well motivated framework called 3-3-1 with right-handed neutrinos model,
for short, mediated by an extra neutral gauge boson .
Following previous works we calculate these sources and in addition we derive
new ones coming from CP-even and -odd neutral scalars which appear due to their
non-diagonal interactions with the physical standard quarks. Furthermore we
show that bounds related to the neutral mesons systems and may be significantly strengthened in the presence of these new
interactions allowing us to infer stronger constraints on the parameter space
of the model.Comment: Published version. 10 pages, 6 figure
(Sub)mm Interferometry Applications in Star Formation Research
This contribution gives an overview about various applications of (sub)mm
interferometry in star formation research. The topics covered are molecular
outflows, accretion disks, fragmentation and chemical properties of low- and
high-mass star-forming regions. A short outlook on the capabilities of ALMA is
given as well.Comment: 20 pages, 7 figures, in proceedings to "2nd European School on Jets
from Young Star: High Angular Resolution Observations". A high-resolution
version of the paper can be found at
http://www.mpia.de/homes/beuther/papers.htm
Dimensionless cosmology
Although it is well known that any consideration of the variations of
fundamental constants should be restricted to their dimensionless combinations,
the literature on variations of the gravitational constant is entirely
dimensionful. To illustrate applications of this to cosmology, we explicitly
give a dimensionless version of the parameters of the standard cosmological
model, and describe the physics of Big Bang Neucleosynthesis and recombination
in a dimensionless manner. The issue that appears to have been missed in many
studies is that in cosmology the strength of gravity is bound up in the
cosmological equations, and the epoch at which we live is a crucial part of the
model. We argue that it is useful to consider the hypothetical situation of
communicating with another civilization (with entirely different units),
comparing only dimensionless constants, in order to decide if we live in a
Universe governed by precisely the same physical laws. In this thought
experiment, we would also have to compare epochs, which can be defined by
giving the value of any {\it one} of the evolving cosmological parameters. By
setting things up carefully in this way one can avoid inconsistent results when
considering variable constants, caused by effectively fixing more than one
parameter today. We show examples of this effect by considering microwave
background anisotropies, being careful to maintain dimensionlessness
throughout. We present Fisher matrix calculations to estimate how well the fine
structure constants for electromagnetism and gravity can be determined with
future microwave background experiments. We highlight how one can be misled by
simply adding to the usual cosmological parameter set
Herschel observations of deuterated water towards Sgr B2(M)
Observations of HDO are an important complement for studies of water, because they give strong constraints on the formation processes – grain
surfaces versus energetic process in the gas phase, e.g. in shocks. The HIFI observations of multiple transitions of HDO in Sgr B2(M) presented
here allow the determination of the HDO abundance throughout the envelope, which has not been possible before with ground-based observations
only. The abundance structure has been modeled with the spherical Monte Carlo radiative transfer code RATRAN, which also takes radiative
pumping by continuum emission from dust into account. The modeling reveals that the abundance of HDO rises steeply with temperature from
a low abundance (2.5 × 10−11) in the outer envelope at temperatures below 100 K through a medium abundance (1.5 × 10−9) in the inner
envelope/outer core at temperatures between 100 and 200 K, and finally a high abundance ( 3.5 × 10−9) at temperatures above 200 K in the hot
core
Origin of the hot gas in low-mass protostars, Herschel-PACS spectroscopy of HH 46
Aims. “Water In Star-forming regions with Herschel” (WISH) is a Herschel key programme aimed at understanding the physical and chemical
structure of young stellar objects (YSOs) with a focus on water and related species.
Methods. The low-mass protostar HH 46 was observed with the Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space
Observatory to measure emission in H2O, CO, OH, [O i], and [C ii] lines located between 63 and 186 μm. The excitation and spatial distribution
of emission can disentangle the different heating mechanisms of YSOs, with better spatial resolution and sensitivity than previously possible.
Results. Far-IR line emission is detected at the position of the protostar and along the outflow axis. The OH emission is concentrated at the
central position, CO emission is bright at the central position and along the outflow, and H2O emission is concentrated in the outflow. In addition,
[O i] emission is seen in low-velocity gas, assumed to be related to the envelope, and is also seen shifted up to 170 km s−1 in both the red- and
blue-shifted jets. Envelope models are constructed based on previous observational constraints. They indicate that passive heating of a spherical
envelope by the protostellar luminosity cannot explain the high-excitation molecular gas detected with PACS, including CO lines with upper levels
at >2500 K above the ground state. Instead, warm CO and H2O emission is probably produced in the walls of an outflow-carved cavity in the
envelope, which are heated by UV photons and non-dissociative C-type shocks. The bright OH and [Oi] emission is attributed to J-type shocks in
dense gas close to the protostar. In the scenario described here, the combined cooling by far-IR lines within the central spatial pixel is estimated to
be 2 × 10−2 L, with 60–80% attributed to J- and C-type shocks produced by interactions between the jet and the envelope
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