5,408 research outputs found
Observations of Small Scale ISM Structure in Dense Atomic Gas
We present high resolution (R~170,000) Kitt Peak National Observatory Co'ude
Feed telescope observations of the interstellar KI 7698 angstrom line towards 5
multiple star systems with saturated NaI components. We compare the KI
absorption line profiles in each of the two (or three) lines of sight in these
systems, and find significant differences between the sight-lines in 3 out of
the 5 cases. We infer that the small scale structure traced by previous NaI
observations is also present in at least some of the components with saturated
NaI absorption lines, and thus the small scale structures traced by the neutral
species are occurring at some level in clouds of all column densities. We
discuss the implications of that conclusion and a potential explanation by
density inhomogeneities
Prevalence of incidental breast cancer and precursor lesions in autopsy studies: A systematic review and meta-analysis
Abstract Background Autopsy studies demonstrate the prevalence pool of incidental breast cancer in the population, but estimates are uncertain due to small numbers in any primary study. We aimed to conduct a systematic review of autopsy studies to estimate the prevalence of incidental breast cancer and precursors. Methods Relevant articles were identified through searching PubMed and Embase from inception up to April 2016, and backward and forward citations. We included autopsy studies of women with no history of breast pathology, which included systematic histological examination of at least one breast, and which allowed calculation of the prevalence of incidental breast cancer or precursor lesions. Data were pooled using logistic regression models with random intercepts (non-linear mixed models). Results We included 13 studies from 1948 to 2010, contributing 2363 autopsies with 99 cases of incidental cancer or precursor lesions. More thorough histological examination (≥20 histological sections) was a strong predictor of incidental in-situ cancer and atypical hyperplasia (OR = 126·8 and 21·3 respectively, p < 0·001), but not invasive cancer (OR = 1·1, p = 0·75). The estimated mean prevalence of incidental cancer or precursor lesion was 19·5% (0·85% invasive cancer + 8·9% in-situ cancer + 9·8% atypical hyperplasia). Conclusion Our systematic review in ten countries over six decades found that incidental detection of cancer in situ and breast cancer precursors is common in women not known to have breast disease during life. The large prevalence pool of undetected cancer in-situ and atypical hyperplasia in these autopsy studies suggests screening programs should be cautious about introducing more sensitive tests that may increase detection of these lesions
Small-Scale Interstellar Na I Structure Toward M92
We have used integral field echelle spectroscopy with the DensePak
fiber-optic array on the KPNO WIYN telescope to observe the central 27" x 43"
of the globular cluster M92 in the Na I D wavelength region at a spatial
resolution of 4". Two interstellar Na I absorption components are evident in
the spectra at LSR velocities of 0 km/s (Cloud 1) and -19 km/s (Cloud 2).
Substantial strength variations in both components are apparent down to scales
limited by the fiber-to-fiber separations. The derived Na I column densities
differ by a factor of 4 across the Cloud 1 absorption map and by a factor of 7
across the Cloud 2 map. Using distance upper limits of 400 and 800 pc for Cloud
1 and Cloud 2, respectively, the absorption maps indicate structure in the ISM
down to scales of 1600 and 3200 AU. The fiber-to-fiber Na I column density
differences toward M92 are comparable to those found in a similar study of the
ISM toward the globular cluster M15. Overall, the structures in the
interstellar components toward M92 have significantly lower column densities
than those toward M15. We interpret these low column density structures as
small-scale turbulent variations in the gas and compare them to the
larger-scale, higher column density variations toward M15, which may be the
hallmarks of actual H I structures.Comment: 9 pages, 2 figures, accepted for publication in ApJ Letter
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Expression of the UL16 glycoprotein of Human Cytomegalovirus protects the virus-infected cell from attack by natural killer cells.
RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.BACKGROUND: Human Cytomegalovirus (HCMV) has acquired through evolution a number of genes to try to evade immune recognition of the virus-infected cell. Many of these mechanisms act to inhibit the MHC class I antigen presentation pathway, but any virus-infected cell which has down-regulated cell surface expression of MHC class I proteins, to avoid CTL attack, would be expected to become susceptible to lysis by Natural Killer cells. Surprisingly, however, HCMV infected fibroblasts were found to be resistant to NK cell mediated cytotoxicity. Expression of the UL16 glycoprotein could represent one mechanism to help the virus to escape from NK cell attack, as it has been shown to bind, in vitro, some of the ligands for NKG2D, the NK cell activating receptor. Here, we explored the role of UL16, in the context of a viral infection, by comparing the susceptibility to NK lysis of cells infected with HCMV and cells infected with a UL16 deletion mutant of this virus. RESULTS: Cells infected with the UL16 knockout virus were killed at substantially higher levels than cells infected with the wild-type virus. This increased killing could be correlated with a UL16-dependent reduction in surface expression of ligands for the NK cell activating receptor NKG2D. CONCLUSIONS: Expression of the UL16 glycoprotein was associated with protection of HCMV-infected cells from NK cell attack. This observation could be correlated with the downregulation of cell surface expression of NKG2D ligands. These data represent a first step towards understanding the mechanism(s) of action of the UL16 protein
Human NKG2D-ligands: cell biology strategies to ensure immune recognition
Immune recognition mediated by the activating receptor NKG2D plays an important role for the elimination of stressed cells, including tumors and virus-infected cells. On the other hand, the ligands for NKG2D can also be shed into the sera of cancer patients where they weaken the immune response by downmodulating the receptor on effector cells, mainly NK and T cells. Although both families of NKG2D-ligands, major histocompatibility complex class I-related chain (MIC) A/B and UL16 binding proteins (ULBPs), are related to MHC molecules and their expression is increased after stress, many differences are observed in terms of their biochemical properties and cell trafficking. In this paper, we summarize the variety of NKG2D-ligands and propose that selection pressure has driven evolution of diversity in their trafficking and shedding, but not receptor binding affinity. However, it is also possible to identify functional properties common to individual ULBP molecules and MICA/B alleles, but not generally conserved within the MIC or ULBP families. These characteristics likely represent examples of convergent evolution for efficient immune recognition, but are also attractive targets for pathogen immune evasion strategies. Categorization of NKG2D-ligands according to their biological features, rather than their genetic family, may help to achieve a better understanding of NKG2D-ligand association with disease
Classification and treatment of angioedema without wheals: A spanish delphi consensus
Introduction Problems in the defnition and classifcation of angioedema, leading to difculties in its diagnosis and treatment, have been identifed; therefore, an improvement in the current classifcation of angioedema is required.
Objective The aim of this study was to propose a practical classifcation of angioedema without wheals that helps to establish
a diferential diagnosis and take appropriate therapeutic decisions.
Methods An initial proposal of classifcation of angioedema without wheals was agreed by a scientifc committee of experts
and was subsequently validated by a panel of experts by means of consensus based on the Delphi methodology. Forty-fve
items on the classifcation, diagnosis, and treatment of angioedema without wheals were proposed for the survey.
Results Most items (93.8%) were agreed after two rounds. All panelists agreed with the proposed classifcation, as well
as with most of the clinical and treatment characteristics. The angioedema without wheals classifcation established three
groups: histamine-mediated, bradykinin-mediated, and unknown mechanism angioedema. The clinical characteristics of
the proposed types of angioedema were also agreed, except for the allergic histamine-mediated and unknown mechanism
angioedema, which generated debate. Regarding treatments, although there was broad agreement with the proposed items,
a lack of knowledge about some treatments in this pathology was observed.
Conclusion The proposed classifcation of angioedema without wheals was accepted with a high degree of agreement;
however, knowledge of available treatments needs to be increased and the defnition of angioedema of unknown mechanism
needs to be improved
Hubungan Kontrasepsi Hormonal, Pengetahuan dan Sikap Tentang Cuti Haid dengan Praktik Cuti Haid pada Pekerja Perempuan PT. Nyonya Meneer Semarang
Background: According to state role on section 81 undang-undang No 13/2003 mentioned that woman workers who are suffering dismenorrhea during menstruations period could take leave on first and second day menstruation. However not all woman workers in PT.Nyonya Meneer Semarang utilize this policy. One of the reason is using hormonal contraception make their period unstable and irregular. The aim of this study was to analyze about relationships between hormonal contraception usage, knowledge and attitude about menstruation leave and the practice of menstruation leave.Method: This research was an explanatory, with a cross sectional approach. The sample recruited from woman workers of PT. Nyonya Meneer Semarang who have age less than 50 years, not menopause, and using hormonal contraception. 81 woman workers were involved in this study selected by simple random sampling. Chi-square test was employed to test significances between variables.Result: The study shows that there was a relationship between hormonal contraception usages with the practice. However, knowledge and attitude of woman workers have no relation with menstrual leave practice. This study suggest that the company should socialize about determination on menstruation leave and the effect to the woman workers in order to makethe woman workers utilize this rule.Keywords: hormonal contraception, rules of menstruation leave, women worke
Seed systems and crop genetic diversity in agroecosystems
Poster presented at the First Diversitas Open Science Conference. Oaxaca (Mexico), 9-12 Nov 200
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