ISO observations toward the reflection nebula NGC 7023: A nonequilibrium ortho- to para-H2 ratio

We have observed the S(0), S(1), S(2), S(3), S(4) and S(5) rotational lines of molecular hydrogen (H2) towards the peak of the photodissociation region (PDR) associated with the reflection nebula NGC 7023. The observed H2 line ratios show that they arise in warm gas with kinetic temperatures ~300 - 700 K. However, the data cannot be fitted by an ortho- to para- (OTP) ratio of 3. An OTP ratio in the range ~1.5 - 2 is necessary to explain our observations. This is the first detection of a non-equilibrium OTP ratio measured from the H2 pure-rotational lines in a PDR. The existence of a dynamical PDR is discussed as the most likely explanation for this low OTP ratio.Comment: 4 pages, 3 figure

First record of bat-pollination in the species-rich genus Tillandsia (Bromeliaceae)

Background and Aims Bromeliaceae is a species-rich neotropical plant family that uses a variety of pollinators, principally vertebrates. Tillandsia is the most diverse genus, and includes more than one-third of all bromeliad species. Within this genus, the majority of species rely on diurnal pollination by hummingbirds; however, the flowers of some Tillandsia species show some characteristics typical for pollination by nocturnal animals, particularly bats and moths. In this study an examination is made of the floral and reproductive biology of the epiphytic bromeliad Tillandsia macropetala in a fragment of humid montane forest in central Veracruz, Mexico. Methods The reproductive system of the species, duration of anthesis, production of nectar and floral scent, as well as diurnal and nocturnal floral visitors and their effectiveness in pollination were determined. Key Results Tillandsia macropetala is a self-compatible species that achieves a higher fruit production through outcrossing. Nectar production is restricted to the night, and only nocturnal visits result in the development of fruits. The most frequent visitor (75 % of visits) and the only pollinator of this bromeliad (in 96 % of visits) was the nectarivorous bat Anoura geoffroyi (Phyllostomidae: Glossophaginae). Conclusions This is the first report of chiropterophily within the genus Tillandsia. The results on the pollination biology of this bromeliad suggest an ongoing evolutionary switch from pollination by birds or moths to bat

An unusual very low-mass high-amplitude pre-main sequence periodic variable

We have investigated the nature of the variability of CHS7797, an unusual periodic variable in the Orion Nebula Cluster. An extensive I-band photometric data set of CHS7797 was compiled between 2004-2010 using various telescopes. Further optical data have been collected in R and z' bands. In addition, simultaneous observations of the ONC region including CHS7797 were performed in the I, J, Ks and IRAC [3.6] and [4.5] bands over a time interval of about 40d. CHS7797 shows an unusual large-amplitude variation of about 1.7 mag in the R, I, and z' bands with a period 17.786. The amplitude of the brightness modulation decreases only slightly at longer wavelengths. The star is faint during 2/3 of the period and the shape of the phased light-curves for seven different observing seasons shows minor changes and small-amplitude variations. Interestingly, there are no significant colour-flux correlations for wavelengths smaller than 2microns, while the object becomes redder when fainter at longer wavelengths. CHS7797 has a spectral type of M6 and an estimated mass between 0.04-0.1Msun. The analysis of the data suggests that the periodic variability of CHS7797 is most probably caused by an orbital motion. Variability as a result of rotational brightness modulation by spots is excluded by the lack of any color-brightness correlation in the optical. The latter indicates that CHS7797 is most probably occulted by circumstellar matter in which grains have grown from typical 0.1 microns to 1-2 micron sizes. We discuss two possible scenarios in which CHS7797 is periodically eclipsed by structures in a disc, namely that CHS7797 is a single object with a circumstellar disc, or that CHS7797 is a binary system, similar to KH15D, in which an inclined circumbinary disc is responsible of the variability. Possible reasons for the typical 0.3mag variations in I-band at a given phase are discussed.Comment: 11 pages, 9 figures, accepted for publication A&

A deeply embedded young protoplanetary disk around L1489 IRS observed by the submillimeter array

Circumstellar disks are expected to form early in the process that leads to the formation of a young star, during the collapse of the dense molecular cloud core. It is currently not well understood at what stage of the collapse the disk is formed or how it subsequently evolves. We aim to identify whether an embedded Keplerian protoplanetary disk resides in the L1489 IRS system. Given the amount of envelope material still present, such a disk would respresent a very young example of a protoplanetary disk. Using the Submillimeter Array (SMA) we have observed the HCO$^+$ $J=$ 3--2 line with a resolution of about 1$''$. At this resolution a protoplanetary disk with a radius of a few hundred AUs should be detectable, if present. Radiative transfer tools are used to model the emission from both continuum and line data. We find that these data are consistent with theoretical models of a collapsing envelope and Keplerian circumstellar disk. Models reproducing both the SED and the interferometric continuum observations reveal that the disk is inclined by 40$^\circ$ which is significantly different to the surrounding envelope (74$^\circ$). This misalignment of the angular momentum axes may be caused by a gradient within the angular momentum in the parental cloud or if L1489 IRS is a binary system rather than just a single star. In the latter case, future observations looking for variability at sub-arcsecond scales may be able to constrain these dynamical variations directly. However, if stars form from turbulent cores, the accreting material will not have a constant angular momentum axis (although the average is well defined and conserved) in which case it is more likely to have a misalignment of the angular momentum axes of the disk and the envelope.Comment: 11 pages, 13 figures, accepted by A&

Properties of active galactic star-forming regions probed by imaging spectroscopy with the Fourier transform spectrometer (FTS) onboard AKARI

We investigate the structure of the interstellar medium (ISM) and identify the location of possible embedded excitation sources from far-infrared (FIR) line and mid-infrared continuum emission maps. We carried out imaging spectroscopic observations of four giant Galactic star-forming regions with the Fourier Transform Spectrometer (FTS) onboard AKARI. We obtained [OIII] 88 micron and [CII] 158 micron line intensity maps of all the regions: G3.270-0.101, G333.6-0.2, NGC3603, and M17. For G3.270-0.101, we obtained high-spatial-resolution [OIII] 88 micron line-emission maps and a FIR continuum map for the first time, which imply that [OIII] 88 micron emission identifies the excitation sources more clearly than the radio continuum emission. In G333.6-0.2, we found a local [OIII] 88 micron emission peak, which is indicative of an excitation source. This is supported by the 18 micron continuum emission, which is considered to trace the hot dust distribution. For all regions, the [CII] 158 micron emission is distributed widely as suggested by previous observations of star-forming regions. We conclude that [OIII] 88 micron emission traces the excitation sources more accurately than the radio continuum emission, especially where there is a high density and/or column density gradient. The FIR spectroscopy provides a promising means of understanding the nature of star-forming regions.Comment: 14 pages with 15 figures, accepted for publication in Astronomy and Astrophysic

Nutrition outcomes of HIV-infected malnourished adults treated with ready-to-use therapeutic food in sub-Saharan Africa: a longitudinal study

ABSTRACT: BACKGROUND: Among people living with HIV/AIDS, nutritional support is increasingly recognized as a critical part of the essential package of care, especially for patients in sub-Saharan Africa. The objectives of the study were to evaluate the outcomes of HIV-positive malnourished adults treated with ready-to-use therapeutic food and to identify factors associated with nutrition programme failure. METHODS: We present results from a retrospective cohort analysis of patients aged 15 years or older with a body mass index of less than 17 kg/m^2 enrolled in three HIV/AIDS care programmes in Africa between March 2006 and August 2008. Factors associated with nutrition programme failure (patients discharged uncured after six or more months of nutritional care, defaulting from nutritional care, remaining in nutritional care for six or more months, or dead) were investigated using multiple logistic regression. RESULTS: Overall, 1340 of 8685 (15.4%) HIV-positive adults were enrolled in the nutrition programme. At admission, median body mass index was 15.8 kg/m2 (IQR 14.9-16.4) and 12% received combination antiretroviral therapy (ART). After a median of four months of follow up (IQR 2.2-6.1), 524 of 1106 (47.4%) patients were considered cured. An overall total of 531 of 1106 (48.0%) patients failed nutrition therapy, 132 (11.9%) of whom died and 250 (22.6%) defaulted from care. Men (OR=1.5, 95% CI 1.2-2.0), patients with severe malnutrition at nutrition programme enrolment (OR=2.2, 95% CI 1.7-2.8), and those never started on ART (OR=4.5, 95% CI 2.7-7.7 for those eligible; OR=1.6, 95% CI 1.0-2.5 for those ineligible for ART at enrolment) were at increased risk of nutrition programme failure. Diagnosed tuberculosis at nutrition programme admission or during follow up, and presence of diarrhoeal disease or extensive candidiasis at admission, were unrelated to nutrition programme failure. CONCLUSIONS: Concomitant administration of ART and ready-to-use therapeutic food increases the chances of nutritional recovery in these high-risk patients. While adequate nutrition is necessary to treat malnourished HIV patients, development of improved strategies for the management of severely malnourished patients with HIV/AIDS are urgently needed

A Spitzer IRS Survey of NGC 1333: Insights into disk evolution from a very young cluster

We report on the {\lambda} = 5-36{\mu}m Spitzer Infrared Spectrograph spectra of 79 young stellar objects in the very young nearby cluster NGC 1333. NGC 1333's youth enables the study of early protoplanetary disk properties, such as the degree of settling as well as the formation of gaps and clearings. We construct spectral energy distributions (SEDs) using our IRS data as well as published photometry and classify our sample into SED classes. Using "extinction-free" spectral indices, we determine whether the disk, envelope, or photosphere dominates the spectrum. We analyze the dereddened spectra of objects which show disk dominated emission using spectral indices and properties of silicate features in order to study the vertical and radial structure of protoplanetary disks in NGC 1333. At least nine objects in our sample of NGC 1333 show signs of large (several AU) radial gaps or clearings in their inner disk. Disks with radial gaps in NGC 1333 show more-nearly pristine silicate dust than their radially continuous counterparts. We compare properties of disks in NGC 1333 to those in three other well studied regions, Taurus-Auriga, Ophiuchus and Chamaeleon I, and find no difference in their degree of sedimentation and dust processing.Comment: 67 pages, 20 figures, accepted to The Astrophysical Journal Supplement Serie

Perceived Discrimination and Self-Reported Quality of Care Among Latinos in the United States

Given the persistence of health and health-care disparities among Latinos in the United States and evidence that discrimination affects health and health care, an investigation of the relationship between perceived discrimination and quality of health care among Latinos is warranted. To examine the relationship of perceived discrimination (in general and in regard to doctors and medical personnel) with self-reported quality of health care and doctor-patient communication in a nationally representative Latino population sample. Participants were 1,067 Latino adults aged ≥18 years living in the US selected via random-digit dialing. Telephone interviews were conducted in 2008 during Wave 2 of the Pew Hispanic Center/Robert Wood Johnson Foundation Hispanic Healthcare Survey. US-born Latinos were twice as likely to report general discrimination as foreign born: 0.32 SD versus −0.23 SD (P < 0.001) on the Detroit Area Survey (DAS) discrimination scale. Higher DAS discrimination was associated with lower self-reported quality of care in US-born Latinos [OR = 0.5; 95% CI (0.3, 0.9); P = 0.009]. For foreign-born Latinos, report of any doctor or medical staff discrimination was associated with lower quality of care [OR = 0.5; 95% CI (0.3, 0.9); P = 0.03], but the DAS was not. For US-born Latinos, doctor discrimination and higher DAS were jointly associated with worse doctor-patient communication. For foreign-born Latinos, the effect of discrimination on doctor-patient communication was significantly smaller than that observed in US-born Latinos. Given the association between perceived discrimination and quality of care, strategies to address discrimination in health-care settings may lead to improved patient satisfaction with care and possibly to improved treatment outcomes

Quorum sensing inhibition in Pseudomonas aeruginosa biofilms: new insights through network mining

Quorum sensing plays a pivotal role in Pseudomonas aeruginosas virulence. This paper reviews experimental results on antimicrobial strategies based on quorum sensing inhibition and discusses current targets in the regulatory network that determines P. aeruginosa biofilm formation and virulence. A bioinformatics framework combining literature mining with information from biomedical ontologies and curated databases was used to create a knowledge network of potential anti-quorum sensing agents for P. aeruginosa. A total of 110 scientific articles, corresponding to 1,004 annotations were so far included in the network and are analysed in this work. Information on the most studied agents, QS targets and methods is detailed. This knowledge network offers a unique view of existing strategies for quorum sensing inhibition and their main regulatory targets and may be used to readily access otherwise scattered information and to help generate new testable hypotheses. This knowledge network is publicly available at http://pcquorum.org/This work was partially funded by the Research Grant 2014 of Anália Lourenço by the European Society of Clinical Microbiology and Infectious Diseases (ESCMID), the INOU16-05 project from the Provincial Council of Ourense, the European Union’s Seventh Framework Programme FP7/ REGPOT-2012-2013.1 [grant agreement number 316265], BIOCAPS, the Portuguese Foundation for Science and Technology (FCT) under the strategic funding of UID/BIO/04469/2013 unit, the FCT and the European Community fund FEDER, through Programme COMPETE, under the scope of the Project RECI/BBB- EBI/0179/2012 [FCOMP-010124-FEDER-027462]. SING group also thanks CITI (Centro de Investigación, Transferencia e Innovación) from University of Vigo for hosting its IT infrastructure. The authors also acknowledge FCT for the PhD Grant to Paula Jorge [grant number SFRH/BD/88192/2012]. M. Pérez-Pérez and G. Pérez Rodríguez were supported by pre-doctoral fellowships from the Xunta de Galicia and the University of Vigo