10,173 research outputs found
Discovery and Cosmological Implications of SPT-CL J2106-5844, the Most Massive Known Cluster at z>1
Using the South Pole Telescope (SPT), we have discovered the most massive known galaxy cluster at z>1, SPT-CL J2106-5844. In addition to producing a strong Sunyaev-Zel'dovich (SZ) effect signal, this system is a luminous X-ray source and its numerous constituent galaxies display spatial and color clustering, all indicating the presence of a massive galaxy cluster. Very Large Telescope and Magellan spectroscopy of 18 member galaxies shows that the cluster is at z = 1.132^(+0.002)_(ā0.003). Chandra observations obtained through a combined HRC-ACIS GTO program reveal an X-ray spectrum with an Fe K line redshifted by z = 1.18 Ā± 0.03. These redshifts are consistent with the galaxy colors found in optical, near-infrared, and mid-infrared imaging. SPT-CL J2106-5844 displays extreme X-ray properties for a cluster having a core-excluded temperature of T_X = 11.0^(+2.6)_(ā1.9) keV and a luminosity (within r _(500)) of LX (0.5-2.0 keV) = (13.9 Ā± 1.0) Ć 10_(44) erg s^(ā1). The combined mass estimate from measurements of the SZ effect and X-ray data is M_(200) = (1.27 Ā± 0.21) Ć 10^(15) h ^(ā1) _(70) M_ā. The discovery of such a massive gravitationally collapsed system at high redshift provides an interesting laboratory for galaxy formation and evolution, and is a probe of extreme perturbations of the primordial matter density field. We discuss the latter, determining that, under the assumption of ĪCDM cosmology with only Gaussian perturbations, there is only a 7% chance of finding a galaxy cluster similar to SPT-CL J2106-5844 in the 2500 deg^2 SPT survey region and that only one such galaxy cluster is expected in the entire sky
Investigation of electrochemistry of high energy compounds in organic electrolytes, november 1, 1964 - april 30, 1965
Conversion by electrochemical process of chemical to electrical energy - high energy compounds in organic electrolytes and cathode material
Investigation of Anaplasma marginale Seroprevalence in a Traditionally Managed Large California Beef Herd.
Recent observations by stakeholders suggested that ecosystem changes may be driving an increased incidence of bovine erythrocytic anaplasmosis, resulting in a reemerging cattle disease in California. The objective of this prospective cohort study was to estimate the incidence of Anaplasma marginale infection using seroconversion in a northern California beef cattle herd. A total of 143 Black Angus cattle (106 prebreeding heifers and 37 cows) were enrolled in the study. Serum samples were collected to determine Anaplasma marginale seroprevalence using a commercially available competitive enzyme-linked immunosorbent assay test kit. Repeat sampling was performed in seronegative animals to determine the incidence density rate from March through September (2013). Seroprevalence of heifers was significantly lower than that of cows at the beginning of the study (P < 0.001) but not at study completion (P = 0.075). Incidence density rate of Anaplasma marginale infection was 8.17 (95% confidence interval: 6.04, 10.81) cases per 1000 cow-days during the study period. Study cattle became Anaplasma marginale seropositive and likely carriers protected from severe clinical disease that might have occurred had they been first infected as mature adults. No evidence was found within this herd to suggest increased risk for clinical bovine erythrocytic anaplasmosis
Recommended from our members
The birth memories and recall questionnaire (BirthMARQ): development and evaluation
Background: Childbirth is a challenging and emotive experience that is accompanied by strong positive and/or negative emotions. Memories of birth may be associated with how women cognitively process birth events postpartum and potentially their adaptation to parenthood. Characteristics of memories for birth may also be associated with postnatal psychological wellbeing. This paper reports the development and evaluation of a questionnaire to measure characteristics of memories of childbirth and to examine the relationship between memories for birth and mental health.
Methods: The Birth Memories and Recall Questionnaire (BirthMARQ) was developed by generating items from literature reviews and general measures of memory characteristics to cover dimensions relevant to childbirth. Fifty nine items were administered to 523 women in the first year after childbirth (M = 23.7 weeks) as part of an online study of childbirth. Validity of the final scale was checked by examining differences between women with and without probable depression and PTSD.
Results: Principal components analysis identified 23 items representing six aspects of memory accounting for 64% of the variance. These were: Emotional memory, Centrality of memory to identity, Coherence, Reliving, Involuntary recall, and Sensory memory. Reliability was good (M alpha = .80). Women with probable depression or PTSD reported more emotional memory, centrality of memories and involuntary recall. Women with probable depression also reported more reliving, and those with probable PTSD reported less coherence and sensory memory.
Conclusion: The results suggest the BirthMARQ is a coherent and valid measure of the characteristics of memory for childbirth which may be important in postnatal mood and psychopathology. While further testing of its reliability and validity is needed, it is a measure capable of becoming a valuable tool for examining memory characteristics in the important context of childbirth
Teaching intercultural communication skills
Aims
The aim of this tool is to develop your understanding of culture, and the need for awareness in intercultural communication. You will be engaged in learning through reflection, knowledge acquisition and practical activities.
Learning outcomes
When you have worked through this tool, you will be able to:
ā¢ Articulate the need for the focus on intercultural communication in current
nursing practice;
ā¢ Discuss the theoretical underpinnings of intercultural communication, and
the meaning of intercultural communication from different viewpoints;
ā¢ Reflect on your own practice in relation to the ability to display intercultural
communication;
ā¢ Reflect on when it might be desirable to communicate competently at an
intercultural level;
ā¢ Identify strategies to nurture confidence in you
Developing tools to promote culturally competent compassion, courage, and intercultural communication in healthcare
Background: Compassion is an important concept in healthcare, and in addition, care should be delivered in a culturally competent manner, taking into account the values, culture, and health beliefs of the individual. However, the training of nurses and other healthcare professionals may not adequately equip them to practice in a manner which is both compassionate and culturally competent. In this paper, we report on the development of three learning tools, designed to promote the skills and strengthen the capacity of nurses and healthcare professionals to provide culturally competent and compassionate care.
Methods: The project involved the participation of six European countries in the development of three learning tools, covering culturally competent compassion, culturally competent courage, and intercultural communication. The principles which informed the methodology derive from the previous work on the Papadopoulos, Tilki and Taylor (PTT) model of transcultural nursing and cultural competence, and were also informed by the Intercultural Education of Nurses in Europe (IENE1 & IENE2) projects. Each partner country was required to produce one tool for each topic area, based on guidance provided by the project co-ordinator, leading to the development of eighteen tools in total. The tools were administered mainly to student nurses to test their feasibility.
Results: The emerging tools contained important theoretical and practical components, whereby innovative learning methods and case studies were included. Student nurses enjoyed using the tools, and enjoyed their flexibility. The learning tools enabled students to become stimulated and to engage together leading to a positive learning experience.
Discussion: The tools allow for a positive learning experience and reflection of good practice to take place. The flexibility and content of the tools allows for them to be of equal value to other healthcare professionals as well as nursing staff.
Conclusion: The tools were initially utilised mainly with student nurses and were received with a positive response. Work is now in place to further implement the tools and evaluate the longer term effects among a range of healthcare professionals and service user health outcomes
On the Interpretation of Supernova Light Echo Profiles and Spectra
The light echo systems of historical supernovae in the Milky Way and local
group galaxies provide an unprecedented opportunity to reveal the effects of
asymmetry on observables, particularly optical spectra. Scattering dust at
different locations on the light echo ellipsoid witnesses the supernova from
different perspectives and the light consequently scattered towards Earth
preserves the shape of line profile variations introduced by asymmetries in the
supernova photosphere. However, the interpretation of supernova light echo
spectra to date has not involved a detailed consideration of the effects of
outburst duration and geometrical scattering modifications due to finite
scattering dust filament dimension, inclination, and image point-spread
function and spectrograph slit width. In this paper, we explore the
implications of these factors and present a framework for future resolved
supernova light echo spectra interpretation, and test it against Cas A and SN
1987A light echo spectra. We conclude that the full modeling of the dimensions
and orientation of the scattering dust using the observed light echoes at two
or more epochs is critical for the correct interpretation of light echo
spectra. Indeed, without doing so one might falsely conclude that differences
exist when none are actually present.Comment: 18 pages, 22 figures, accepted for publication in Ap
Evidence for a Photospheric Component in the Prompt Emission of the Short GRB120323A and its Effects on the GRB Hardness-Luminosity Relation
The short GRB 120323A had the highest flux ever detected with the Fermi/GBM.
Here we study its remarkable spectral properties and their evolution using two
spectral models: (i) a single emission component scenario, where the spectrum
is modeled by the empirical Band function, and (ii) a two component scenario,
where thermal (Planck-like) emission is observed simultaneously with a
non-thermal component (a Band function). We find that the latter model fits the
integrated burst spectrum significantly better than the former, and that their
respective spectral parameters are dramatically different: when fit with a Band
function only, the Epeak of the event is unusually soft for a short GRB, while
adding a thermal component leads to more typical short GRB values. Our
time-resolved spectral analysis produces similar results. We argue here that
the two-component model is the preferred interpretation for GRB 120323A, based
on: (i) the values and evolution of the Band function parameters of the two
component scenario, which are more typical for a short GRB, and (ii) the
appearance in the data of a significant hardness-intensity correlation,
commonly found in GRBs, when we employee two-component model fits; the
correlation is non-existent in the Band-only fits. GRB 110721A, a long burst
with an intense photospheric emission, exhibits the exact same behavior. We
conclude that GRB 120323A has a strong photospheric emission contribution,
first time observed in a short GRB. Magnetic dissipation models are difficult
to reconcile with these results, which instead favor photospheric thermal
emission and fast cooling synchrotron radiation from internal shocks. Finally,
we derive a possibly universal hardness-luminosity relation in the source frame
using a larger set of GRBs L,i=(1.59+/-0.84).10^50 (Epeak,i)^(1.33+/-0.07)
erg/s), which could be used as a possible redshift estimator for cosmology.Comment: 27 pages, 13 figures, Accepted by ApJ (April, 7th 2013
- ā¦