615 research outputs found
Palouse Prairie: Ethics Behind the Loss of an Ecosystem
There is an ethical tradeoff between growing high-yield agricultural products and the integrity and goodness of an ecosystem. Why must we protect an ecosystem and prevent extinction of other organisms? One might claim that the human benefit gained from environmental destructions for the purpose of agriculture is more valuable than any life or structure that existed in the ecosystem. In the case of the Palouse Prairie in Eastern Washington, early white settlers in the area valued the monetary gains from agriculture more than any goodness of an intact ecosystem. Unlike the benefits gained from farming (which could be attained through more sustainable means), what is lost with the destruction of an ecosystem or the extinction of a species can never be restored. I will argue that humans are morally obligated to not destroy living lineages when altering a landscape. A brief case study of the Palouse Prairie will illustrate that the small-scale, land-altering decisions made by the few farmers of the Palouse have caused long-term harms for the current and future inhabitants of the ecosystem, and that humans ought to make reparations for those harms. Because evolution grants the potential for any lineage to advance and better its individuals, the processes of evolution must be respected in any ecosystem. Any lineage’s process of perpetuation must be morally considerable, as is any living organism’s will to live. To offer a practical guideline for land alteration, I conclude with the suggestion that all lineages of life receive freedom of environment, perpetuity, and adaptation
Evidence for a Mid-Atomic-Number Atmosphere in the Neutron Star 1E1207.4-5209
Recently Sanwal et al. (2002) reported the first clear detection of
absorption features in an isolated neutron star, 1E1207.4-5209. Remarkably
their spectral modeling demonstrates that the atmosphere cannot be Hydrogen.
They speculated that the neutron star atmosphere is indicative of ionized
Helium in an ultra-strong (~1.5x10^{14} G) magnetic field. We have applied our
recently developed atomic model (Mori & Hailey 2002) for strongly-magnetized
neutron star atmospheres to this problem. We find that this model, along with
some simp le atomic physics arguments, severely constrains the possible
composition of the atmosphere. In particular we find that the absorption
features are naturally associated with He-like Oxygen or Neon in a magnetic
field of ~10^{12} G, comparable to the magnetic field derived from the spin
parameters of the neutron star. This interpretation is consistent with the
relative line strengths and widths and is robust. Our model predicts possible
substructure in the spectral features, which has now been reported by
XMM-Newton (Mereghetti et al. 2002). However we show the Mereghetti et al.
claim that the atmosphere is Iron or some comparable high-Z element at ~
10^{12} G is easily ruled out by the Chandra and XMM-Newton data.Comment: 5 pages, AASTeX, Revised version. Accepted for publication in ApJ
Letter
A systematic review of behaviour change techniques used in interventions to increase physical activity among breast cancer survivors
BACKGROUND: Despite evidence that physical activity (PA) can help reduce recurrence and mortality, many breast cancer survivors are less active than recommended levels. The aim of this systematic review is to advance our understanding of which behaviour change techniques (BCTs) have been used in interventions promoting breast cancer survivors' PA and to evaluate their potential to increase PA. METHODS: A systematic search was conducted in five databases (Medline; PsycInfo; Embase; CINAHL and Scopus) for studies published between 2005 and 2019. Following a rigorous screening process, 27 studies were retained. These were reviewed and analysed for quality, coded for BCTs (k = 0.65) and interventions categorised according to their potential to increase PA using an established methodology. RESULTS: The majority of studies were moderate quality (64%). Demonstration on how to perform the behaviour was the most commonly used BCT (n = 23). Adding objects to the environment, (pedometer or accelerometer) was the BCT with the highest potential to increase PA. This was followed by, goal setting and self-monitoring of behaviour. A theory-based approach to evaluation was used in only 59% (n = 16) of the studies. CONCLUSIONS: The results of this review inform which BCTs have the potential to increase PA for breast cancer survivors and inform intervention development. Future research, is encouraged to properly report intervention procedures around dose and frequency of intervention components to allow for review and replication
Association between neighbourhood cohesion and physical activity trajectories during the COVID-19 pandemic using data from Understanding Society: The UK Household Longitudinal Study & COVID-19 sub-study
Neighbourhood cohesion is increasingly recognised as a key determinant of health and health-related behaviours. Positive association between social support and physical activity have been demonstrated on an interpersonal level, there is less evidence at group-level. This study aimed to examine the association between neighbourhood cohesion and physical activity trajectories during the COVID-19 pandemic. Hypothesizing that higher neighbourhood cohesion was a protective factor against reduced physical activity during the pandemic. Data from Understand Society (wave 9, Jan 2017–Dec 2019), and the COVID-19 sub-study (waves 1, 5, 7) was used. Participants (N = 14,475) had baseline data and at least one Covid physical activity measure. We used linear mixed models with a random intercept and slope at the individual level and an unstructured correlation matrix to examine the association between neighbourhood cohesion and physical activity during the follow-up period. We found a significant reduction in physical activity (-441 MET-min/wk, (CI 374.51 – 507.65, p < 0.001) through the COVID-19 pandemic, and that higher neighbourhood cohesion was related to higher physical activity after control for covariates. There was a significant difference between neighbourhood cohesion categories and change seen in PA during the 39-month follow-up period (difference in change between lowest and highest neighbourhood cohesion categories = 373 MET-min/wk, p = 0.036), higher neighbourhood cohesion had a protective effect. Strong relationships between public health and urban planning sectors are needed to build communities with structures in place to support a sense of community, social interaction and attraction to the neighbourhood. This will help long-term neighbourhood cohesion and support increased physical activity
Delphinapterus Leucas\u27 Spatial Use and Social Behavior: The Study of a Managed Care Environment
Little is known about belugas in managed care. Previous studies evaluated socio-sexual behavior in belugas across multiple facilities, but little data has been collected on their spatial use within a habitat (i.e., Hill, et al., 2015)
One-electron atomic-molecular ions containing Lithium in a strong magnetic field
The one-electron Li-containing Coulomb systems of atomic type and
molecular type , and are studied in
the presence of a strong magnetic field a.u. in the
non-relativistic framework. They are considered at the Born-Oppenheimer
approximation of zero order (infinitely massive centers) within the parallel
configuration (molecular axis parallel to the magnetic field). The variational
and Lagrange-mesh methods are employed in complement to each other. It is
demonstrated that the molecular systems , and
can exist for sufficiently strong magnetic fields a.u. and that can even be stable at
magnetic fields typical of magnetars.Comment: 22 pages, 9 figures, 4 table
Multi-wavelength observations of 2HWC J1928+177: dark accelerator or new TeV gamma-ray binary?
2HWC J1928+177 is a Galactic TeV gamma-ray source detected by the High
Altitude Water Cherenkov (HAWC) Observatory up to ~ 56 TeV. The HAWC source,
later confirmed by H.E.S.S., still remains unidentified as a dark accelerator
since there is no apparent supernova remnant or pulsar wind nebula detected in
the lower energy bands. The radio pulsar PSR J1928+1746, coinciding with the
HAWC source position, has no X-ray counterpart. Our SED modeling shows that
inverse Compton scattering in the putative pulsar wind nebula can account for
the TeV emission only if the unseen nebula is extended beyond r ~ 4 [arcmin].
Alternatively, TeV gamma rays may be produced by hadronic interactions between
relativistic protons from an undetected supernova remnant associated with the
radio pulsar and a nearby molecular cloud G52.9+0.1. NuSTAR and Chandra
observations detected a variable X-ray point source within the HAWC error
circle, potentially associated with a bright IR source. The X-ray spectra can
be fitted with an absorbed power-law model with cm and and exhibit
long-term X-ray flux variability over the last decade. If the X-ray source,
possibly associated with the IR source (likely an O star), is the counterpart
of the HAWC source, it may be a new TeV gamma-ray binary powered by collisions
between the pulsar wind and stellar wind. Follow-up X-ray observations are
warranted to search for diffuse X-ray emission and determine the nature of the
HAWC source.Comment: accepted to ApJ, 8 pages, 7 figure
NuSTAR + XMM-Newton monitoring of the neutron star transient AX J1745.6-2901
AX J1745.6-2901 is a high-inclination (eclipsing) transient neutron star (NS)
Low Mass X-ray Binary (LMXB) showcasing intense ionised Fe K absorption. We
present here the analysis of 11 XMM-Newton and 15 NuSTAR new data-sets
(obtained between 2013-2016), therefore tripling the number of observations of
AX J1745.6-2901 in outburst. Thanks to simultaneous XMM-Newton and NuSTAR
spectra, we greatly improve on the fitting of the X-ray continuum. During the
soft state the emission can be described by a disk black body (
keV and inner disc radius km), plus hot ( keV)
black body radiation with a small emitting radius ( km)
likely associated with the boundary layer or NS surface, plus a faint
Comptonisation component. Imprinted on the spectra are clear absorption
features created by both neutral and ionised matter. Additionally, positive
residuals suggestive of an emission Fe K disc line and consistent with
relativistic ionised reflection are present during the soft state, while such
residuals are not significant during the hard state. The hard state spectra are
characterised by a hard () power law, showing no evidence
for a high energy cut off ( keV) and implying a small optical
depth (). The new observations confirm the previously witnessed trend
of exhibiting strong Fe K absorption in the soft state, that significantly
weakens during the hard state. Optical (GROND) and radio (GMRT) observations
suggest for AX J1745.6-2901 a standard broad band SED as typically observed in
accreting neutron stars.Comment: Accepted for publication in MNRA
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