Relationships of Parental Uncertainty and Caregiver Burden to Adjustment Outcomes in Children with Cancer: the Moderating Role of Parenting Stress

The current study sought to determine whether levels of parental uncertainty and caregiver burden, as reported by parents of children with pediatric cancer, were related to the child's emotional, behavioral, and social functioning. Additionally, the moderating role of parenting stress in these relationships was investigated. Data were collected from 46 parents of children on treatment for cancer at the time of participation. Parents completed the Parental Perceptions of Uncertainty Scale, the Care of My Child with Cancer Scale, the Parenting Stress Index, and rated their child's functioning using the Behavior Assessment System for Children - 2nd Edition and the Social Skills Rating Scale. Results indicated that, contrary to expectations, neither levels of parental uncertainty nor levels of caregiver burden were significantly related to the child's emotional, behavioral, or social functioning. Additionally, although parenting stress did not moderate the relationships between parental uncertainty and child adjustment, level of parenting stress emerged as a significant independent predictor of the child's emotional and social functioning. Moreover, parenting stress did not moderate the relationship between caregiver burden and child adjustment in the total sample of parents, but did moderate the relationship between caregiver burden and child emotional functioning in the subset of mothers only. Specifically, children evidenced better emotional adjustment under conditions of high caregiver burden and low parenting stress, and poorer emotional adjustment under conditions of low caregiver burden and low parenting stress. It is suggested that mothers who are evidencing higher level of burden due to their hands-on involvement in the child's treatment and care, but are not overwhelmed by the situation (i.e., report lower stress), have children who are better adjusted with regard to their emotional functioning. On the other hand, mothers who reported low levels of both caregiver burden and parenting stress may be distancing themselves from the situation of the child's illness, and therefore distancing themselves emotionally from their child, which could result in the child feeling isolated, sad, withdrawn, or worried.Department of Psycholog

On the sizes of z>2 Damped Lyman-alpha Absorbing Galaxies

Recently, the number of detected galaxy counterparts of z > 2 Damped Lyman-alpha Absorbers in QSO spectra has increased substantially so that we today have a sample of 10 detections. M{\o}ller et al. in 2004 made the prediction, based on a hint of a luminosity-metallicity relation for DLAs, that HI size should increase with increasing metallicity. In this paper we investigate the distribution of impact parameter and metallicity that would result from the correlation between galaxy size and metallicity. We compare our observations with simulated data sets given the relation of size and metallicity. The observed sample presented here supports the metallicity-size prediction: The present sample of DLA galaxies is consistent with the model distribution. Our data also show a strong relation between impact parameter and column density of HI. We furthermore compare the observations with several numerical simulations and demonstrate that the observations support a scenario where the relation between size and metallicity is driven by feedback mechanisms controlling the star-formation efficiency and outflow of enriched gas.Comment: Accepted for publishing in MNRAS lette

Uncovering strong MgII absorbing galaxies: Imaging below the Lyman limit

The nature of the galaxies that give rise to absorption lines, such as damped Lyman-alpha systems (DLAs) or strong MgII lines, in quasar spectra is difficult to investigate in emission. Taking advantage of the total absorption of the QSO light bluewards of the Lyman limit of two DLAs at z>3.4, we look for the continuum emission from intervening galaxies at z~2 that are identified via strong metal absorption lines. The MgII absorbers have equivalent width large enough to be potential DLA systems. Deep images are obtained with the FOcal Reducer and Spectrograph (FORS1) on the Very Large Telescope for the fields towards SDSS J110855+120953 and SDSS J140850+020522. These quasars have MgII absorption lines at z=1.87 (W_r(MgII)=2.46 A) and z=1.98 (W_r(MgII)=1.89 A), respectively, and each QSO has two intervening higher redshift DLAs at z>3. The U and R bands of FORS1 lie blue and redwards of the Lyman limit of the background DLAs, allowing us to search for emission from the foreground galaxies directly along the lines of sight to the QSOs. No galaxies are found close to the sight line of the QSO to a point source limit of U_AB=28.0. In both fields, the closest objects lie at an impact parameter of 5 arcsec corresponding to 40 kpc in projection at z=2, and have typical colours of star forming galaxies at that redshift. However, the currently available data do not allow us to confirm if the galaxies lie at the same redshifts as the absorption systems. A more extended structure is visible in the SDSS J14085+020522 field at an impact parameter of 0.8 arcsec or 7 kpc. If these objects are at z~2 their luminosities are 0.03-0.04 L* in both fields. The star formation rates estimated from the UV flux are 0.5-0.6 M_sun yr^-1. (Abbreviated).Comment: 10 pages, Accepted for publication in A&

Relationship Between Post-Treatment Intellectual Functioning and Long-Term Social Functioning in Survivors of Pediatric Cancer

The current study sought 1) to determine whether post-treatment intellectual functioning was associated with current levels of emotional, behavioral, and social functioning in survivors of pediatric cancer; and 2) whether survivors of pediatric brain tumors differed from survivors of other types of pediatric cancer on measures of social functioning. Participants included 30 children and adolescents who underwent treatment for childhood cancer, and received a post-treatment neuropsychological evaluation. Child participants completed the Behavior Assessment System for Children, 2nd Edition (BASC-2), the Loneliness and Social Dissatisfaction Questionnaire (LSDQ), the Social Support Scale for Children, and the Self-Perception Profile. The parent participants rated their child's current functioning using the BASC-2, and a revised version of the LSDQ. Results revealed that post-treatment intellectual functioning was not related to current adjustment outcomes. Further, survivors of pediatric brain tumors reported significantly higher levels of current perceived social competence than survivors of other types of pediatric cancer.Department of Psycholog

Practice patterns and outcomes of pediatric partial nephrectomy in the United States: Comparison between pediatric urology and general pediatric surgery

BACKGROUND: In the United States, both pediatric urologists (PUROs) and general pediatric surgeons (GPSs) perform nephrectomies in children, with PUROs performing more nephrectomies overall, most commonly for benign causes. GPSs perform more nephrectomies for malignant causes. We questioned whether the same trends persisted for partial nephrectomy. OBJECTIVE: We hypothesized that PUROs performed more partial nephrectomies for all causes, including malignancy. Our primary aim was to characterize the number of partial nephrectomies performed by PUROs and GPSs. We also compared short-term outcomes between subspecialties. STUDY DESIGN: We analyzed the Pediatric Health Information System (PHIS), a database encompassing data from 44 children\u27s hospitals. Patients were ≤18 years old and had a partial nephrectomy (ICD-9 procedure code 554) carried out by PUROs or GPSs between 1 January, 2004 and June 30, 2013. Queried data points included surgeon subspecialty, age, gender, 3M™ All Patient Refined Diagnosis Related Groups (3M™ APR DRG) code, severity level, mortality risk, length of stay (LOS), and medical/surgical complication flags. Data points were compared in patients on whom PUROs and GPSs had operated. Statistical analysis included the Student t test, chi-square test, analysis of covariance, and logistic regression. RESULTS: Results are presented in the table. While PUROs performed the majority of partial nephrectomies, GPSs operated more commonly for malignancy. For surgeries performed for non-malignant indications, PURO patients had a shorter LOS and lower complication rate after controlling for statistically identified covariates. There was no difference in LOS or complication rate for patients with malignancy. DISCUSSION: A Pediatric Health Information System study of pediatric nephrectomy demonstrated PUROs performed more nephrectomies overall, but GPSs performed more surgeries for malignancy. The difference was less dramatic for partial nephrectomies (63% GPS, 37% PURO) than for radical nephrectomies (90% GPS, 10% PURO). PUROs performed more partial nephrectomies for benign indications (94% PURO, 6% GPS) at an even greater rate than nephrectomies (88% PURO, 12% GPS). As a national database study, there are a number of inherent limitations: applicability of results to non-participating hospitals, possibility of inaccurate data entry/coding, and lack of data points that would be relevant to the study. CONCLUSIONS: While most partial nephrectomies in the United States are performed by PUROs, GPSs perform the majority of surgeries for malignancy. There is no difference in LOS or complication rate undergoing nephron-sparing surgery for malignant disease; however, PUROs had a shorter LOS and lower complication rate when operating for benign diseases

A joint model for the emission and absorption properties of damped Lyman alpha absorption systems

The recently discovered population of ultra-faint extended line emitters can account for the majority of the incidence rate of Damped Lyman Alpha systems (DLAs) at z ~ 3 if the line emission is interpreted as Ly alpha. We show here that a model similar to that proposed by Haehnelt, Steinmetz, & Rauch (2000), which explains the incidence rate and kinematics of DLAs in the context of $\Lambda$CDM models for structure formation, also reproduces the size distribution of the new population of faint Ly alpha emitters for plausible parameters. This lends further support to identification of the emitters with the hitherto elusive population of DLA host galaxies. The observed incidence rate of DLAs together with the observed space density and size distribution of the emitters suggest a duty cycle of ~ 0.2 - 0.4 for the Ly alpha emission from DLA host galaxies. We further show that Ly alpha cooling is expected to contribute little to the Ly alpha emission for the majority of emitters. This leaves centrally concentrated star formation at a rate of a few tenths M_sun/yr, surrounded by extended Ly alpha halos with radii up to 30-50 kpc, as the most plausible explanation for the origin of the emission. Both the luminosity function of Ly alpha emission and the velocity width distribution of low ionization absorption require that galaxies inside Dark Matter (DM) halos with virial velocities < 50 - 70 km/s contribute little to the incidence rate of DLAs at z ~ 3, suggesting that energy and momentum input due to star formation efficiently removes gas from these halos. Galaxies with DM halos with virial velocities of 100 - 150 km/s appear to account for the majority of DLA host galaxies. DLA host galaxies at z ~ 3 should thus become the building blocks of typical present-day galaxies.Comment: 9 Pages, 4 Figures. Submitted to MNRA

Directly imaging damped Lyman-alpha galaxies at z>2. I: Methodology and First Results

We present the methodology for, and the first results from, a new imaging program aimed at identifying and characterizing the host galaxies of damped Lyman-alpha absorbers (DLAs) at z>2. We target quasar sightlines with multiple optically-thick HI absorbers and use the higher-redshift system as a "blocking filter" (via its Lyman-limit absorption) to eliminate all far-ultraviolet (FUV) emission from the quasar. This allows us to directly image the rest-frame FUV continuum emission of the lower-redshift DLA, without any quasar contamination and with no bias towards large impact parameters. We introduce a formalism based on galaxy number counts and Bayesian statistics with which we quantify the probability that a candidate is the DLA host galaxy. This method will allow the identification of a bona fide sample of DLAs that are too faint to be spectroscopically confirmed. The same formalism can be adopted to the study of other quasar absorption line systems (e.g. MgII absorbers). We have applied this imaging technique to two QSO sightlines. For the z~2.69 DLA towards J073149+285449, a galaxy with impact parameter b=1.54"=11.89 kpc and implied star formation rate (SFR) of ~5 M/yr is identified as the most reliable candidate. In the case of the z~2.92 DLA towards J211444-005533, no likely host is found down to a 3-sigma SFR limit of 1.4 M/yr. Studying the HI column density as a function of the impact parameter, including 6 DLAs with known hosts from the literature, we find evidence that the observed HI distribution is more extended than what is generally predicted from numerical simulation.Comment: 22 pages, 13 figures. Accepted for publication in MNRAS. Typos correcte

Velocity-Metallicity Correlation for high-z DLA Galaxies: Evidence for a Mass-Metallicity Relation?

We used our database of VLT-UVES quasar spectra to build up a sample of 70 Damped Lyman-alpha (DLA) or strong sub-DLA systems with total neutral hydrogen column densities of log N(HI)>20 and redshifts in the range 1.7<z_abs<4.3. For each of the systems, we measured in an homogeneous manner the metallicities relative to Solar, [X/H] (with X=Zn, or S or Si), and the velocity widths of low-ionization line profiles, Delta V. We provide for the first time evidence for a correlation between DLA metallicity and line profile velocity width, which is detected at the 6.1sigma significance level. This confirms the trend previously observed in a much smaller sample by Wolfe & Prochaska (1998). The best-fit linear relation is [X/H]=1.55(\pm 0.12) log Delta V -4.33(\pm 0.23) with Delta V expressed in km/s. The slope of the DLA velocity-metallicity relation is the same within uncertainties between the higher (z_abs>2.43) and the lower (z_abs<2.43) redshift halves of our sample. However, the two populations of systems are statistically different. There is a strong redshift evolution in the sense that the mean metallicity and mean velocity width increase with decreasing redshift. We argue that the existence of a DLA velocity-metallicity correlation, over more than a factor of 100 spread in metallicity, is probably the consequence of an underlying mass-metallicity relation for the galaxies responsible for DLA absorption lines. Assuming a simple linear scaling of the galaxy luminosity with the mass of the dark-matter halo, we find that the slope of the DLA velocity-metallicity relation is consistent with that of the luminosity-metallicity relation derived for local galaxies. [...] abridged.Comment: 10 pages, 4 figures, A&A in pres

Detection of Lyman-alpha emission from a DLA galaxy: Possible implications for a luminosity-metallicity relation at z = 2-3

In an ongoing programme to identify a sample of high z DLA galaxies we have found the long sought for case of a Ly-alpha emitter seen in the centre of a broad DLA trough. This is the predicted `textbook case' of an intervening DLA galaxy if DLA galaxies are small, but would not be expected if intervening high redshift DLA galaxies have large gaseous disks. The Ly-alpha flux is 5.4{+2}{-0.8} * 1e-17 ergs/s/cm2 similar to what has been found in previously known high z DLA galaxies. The impact parameter is found to be 0.3+-0.3 arcsec. This is smaller than what was found in previous cases but still consistent with random sight-lines through absorbers with mean impact parameter ~1 arcsec. Of the 24 DLAs targeted in the NICMOS imaging survey five have now been identified as Ly-alpha emitters. The DLA galaxies with detected Ly-alpha emission tend to have higher interstellar metallicities than those with undetected Ly-alpha emission. This is plausibly explained as a consequence of a positive correlation between the Ly-alpha line luminosities of the galaxies and their metallicities, although the present sample is too small for a definitive conclusion. The available observations of high-redshift DLA galaxies are also consistent with a negative correlation between Ly-alpha equivalent widths and metallicities, as seen in nearby star-forming galaxies and usually attributed to the preferential absorption of Ly-alpha photons by dust grains.Comment: Accepted for publication in A&A-Letter

The distribution of equivalent widths in long GRB afterglow spectra

The extreme brightness of gamma-ray burst (GRB) afterglows and their simple spectral shape make them ideal beacons to study the interstellar medium of their host galaxies through absorption line spectroscopy. Using 69 low-resolution GRB afterglow spectra, we conduct a study of the rest-frame equivalent width (EW) distribution of features with an average rest-frame EW larger than 0.5 A. To compare an individual GRB with the sample, we develop EW diagrams as a graphical tool, and we give a catalogue with diagrams for the 69 spectra. We introduce a line strength parameter (LSP) that allows us to quantify the strength of the absorption features as compared to the sample by a single number. Using the distributions of EWs of single-species features, we derive the distribution of column densities by a curve of growth (CoG) fit. We find correlations between the LSP and the extinction of the GRB, the UV brightness of the host galaxies and the neutral hydrogen column density. However, we see no significant evolution of the LSP with the redshift. There is a weak correlation between the ionisation of the absorbers and the energy of the GRB, indicating that, either the GRB event is responsible for part of the ionisation, or that galaxies with high-ionisation media produce more energetic GRBs. Spectral features in GRB spectra are, on average, 2.5 times stronger than those seen in QSO intervening damped Lyman-alpha (DLA) systems and slightly more ionised. In particular we find larger excess in the EW of CIV1549 relative to QSO DLAs, which could be related to an excess of Wolf-Rayet stars in the environments of GRBs. From the CoG fitting we obtain an average number of components in the absorption features of GRBs of 6.00(-1.25,+1.00). The most extreme ionisation ratios in our sample are found for GRBs with low neutral hydrogen column density, which could be related to ionisation by the GRB emission.Comment: 37 pages, 31 figures, 15 tables. Accepted for publication in Astonomy and Astrophysic