Support after brain tumor means different things: Family caregivers\u27 experiences of support and relationship changes

Shorter hospital stays and greater emphasis on outpatient care means that family members have the primary responsibility for supporting a person with brain tumor to manage the physical, cognitive, behavioral, and emotional effects of the illness and its treatment. Given the integral role of family caregivers, it is essential to understand their experience of the impact of brain tumor and their own support needs. Accordingly, this qualitative study aimed to investigate family caregivers\u27 experiences of support and relationship changes in the context of brain tumor. In-depth interviews were conducted with 11 family caregivers (8 spouse/partner, 3 parents) of people with malignant or benign tumor. A thematic analysis of interview transcripts identified two major themes, namely, Meanings of Support and Relationship Impacts. The Meanings of Support theme was characterized by intertwined and distinct support needs, varied expectations of support and factors influencing support expectations. The Relationship Impacts theme depicted mixed experiences of strengthened, maintained, and strained relations with the person with brain tumor. Overall, the findings highlight that there is considerable variability in caregivers\u27 experiences and expectations of support and the impact of brain tumor on relationships. The implications of these findings for the provision of caregiver support are discussed

Instability, Intermixing and Electronic Structure at the Epitaxial LaAlO3/SrTiO3(001) Heterojunction

The question of stability against diffusional mixing at the prototypical LaAlO3/SrTiO3(001) interface is explored using a multi-faceted experimental and theoretical approach. We combine analytical methods with a range of sensitivities to elemental concentrations and spatial separations to investigate interfaces grown using on-axis pulsed laser deposition. We also employ computational modeling based on the density function theory as well as classical force fields to explore the energetic stability of a wide variety of intermixed atomic configurations relative to the idealized, atomically abrupt model. Statistical analysis of the calculated energies for the various configurations is used to elucidate the relative thermodynamic stability of intermixed and abrupt configurations. We find that on both experimental and theoretical fronts, the tendency toward intermixing is very strong. We have also measured and calculated key electronic properties such as the presence of electric fields and the value of the valence band discontinuity at the interface. We find no measurable electric field in either the LaAlO3 or SrTiO3, and that the valence band offset is near zero, partitioning the band discontinuity almost entirely to the conduction band edge. Moreover, we find that it is not possible to account for these electronic properties theoretically without including extensive intermixing in our physical model of the interface. The atomic configurations which give the greatest electrostatic stability are those that eliminate the interface dipole by intermixing, calling into question the conventional explanation for conductivity at this interface - electronic reconstruction. Rather, evidence is presented for La indiffusion and doping of the SrTiO3 below the interface as being the cause of the observed conductivity

Surface effects on nanowire transport: numerical investigation using the Boltzmann equation

A direct numerical solution of the steady-state Boltzmann equation in a cylindrical geometry is reported. Finite-size effects are investigated in large semiconducting nanowires using the relaxation-time approximation. A nanowire is modelled as a combination of an interior with local transport parameters identical to those in the bulk, and a finite surface region across whose width the carrier density decays radially to zero. The roughness of the surface is incorporated by using lower relaxation-times there than in the interior. An argument supported by our numerical results challenges a commonly used zero-width parametrization of the surface layer. In the non-degenerate limit, appropriate for moderately doped semiconductors, a finite surface width model does produce a positive longitudinal magneto-conductance, in agreement with existing theory. However, the effect is seen to be quite small (a few per cent) for realistic values of the wire parameters even at the highest practical magnetic fields. Physical insights emerging from the results are discussed.Comment: 15 pages, 7 figure

Evaporation of a Kerr black hole by emission of scalar and higher spin particles

We study the evolution of an evaporating rotating black hole, described by the Kerr metric, which is emitting either solely massless scalar particles or a mixture of massless scalar and nonzero spin particles. Allowing the hole to radiate scalar particles increases the mass loss rate and decreases the angular momentum loss rate relative to a black hole which is radiating nonzero spin particles. The presence of scalar radiation can cause the evaporating hole to asymptotically approach a state which is described by a nonzero value of $a_* \equiv a / M$. This is contrary to the conventional view of black hole evaporation, wherein all black holes spin down more rapidly than they lose mass. A hole emitting solely scalar radiation will approach a final asymptotic state described by $a_* \simeq 0.555$. A black hole that is emitting scalar particles and a canonical set of nonzero spin particles (3 species of neutrinos, a single photon species, and a single graviton species) will asymptotically approach a nonzero value of $a_*$ only if there are at least 32 massless scalar fields. We also calculate the lifetime of a primordial black hole that formed with a value of the rotation parameter $a_{*}$, the minimum initial mass of a primordial black hole that is seen today with a rotation parameter $a_{*}$, and the entropy of a black hole that is emitting scalar or higher spin particles.Comment: 22 pages, 13 figures, RevTeX format; added clearer descriptions for variables, added journal referenc

Sex differences in the efficacy of psychological therapies for the management of chronic and recurrent pain in children and adolescents:a systematic review and meta-analysis

Sex differences in chronic pain are reported to emerge during adolescence, although it is unclear if this includes responses to treatment. We conducted a meta-analysis to examine whether sex differences were present on outcome variables at pre-treatment, and whether the efficacy of psychological therapies for pediatric chronic pain differs between boys and girls at post-treatment and follow-up time points. Searches were conducted, extending two existing Cochrane reviews of randomized-controlled trials examining the efficacy of psychological therapies for chronic and recurrent pain in children and adolescents. Forty-six articles were eligible for inclusion, and data were extracted regarding pain, disability, anxiety, and depression in boys and girls at pre-treatment, post-treatment, and follow-up time points. No published study reported outcome data separately by sex, so authors of all studies were contacted and 17 studies provided data. Twice as many girls (n =1760) were enrolled into clinical trials of psychological therapies for pediatric chronic pain than boys (n = 828). Girls reported higher depression and anxiety at pre-treatment than boys. Girls with headache also reported significantly greater pre-treatment pain severity. Treatment gains were consistent across the sexes. One exception was for post-treatment disability in children with non-headache pain conditions; girls exhibited a significant effect of treatment relative to control condition (SMD= -0.50[-0.80,-0.20], p &lt; .01), but no such effect was observed for boys (SMD= -0.08[-0.44,0.28], p = .66). Future research should examine whether mechanisms of treatment efficacy differ between boys and girls, and consider the impact of pre-treatment sex differences on response to treatment.</p

Habitable Planet Formation in Binary-Planetary Systems

Recent radial velocity observations have indicated that Jovian-type planets can exist in moderately close binary star systems. Numerical simulations of the dynamical stability of terrestrial-class planets in such environments have shown that, in addition to their giant planets, these systems can also harbor Earth-like objects. In this paper, we study the late stage of terrestrial planet formation in such binary-planetary systems, and present the results of the simulations of the formation of Earth-like bodies in their habitable zones. We consider a circumprimary disk of Moon- to Mars-sized objects and numerically integrate the orbits of these bodies at the presence of the Jovian-type planet of the system and for different values of the mass, semimajor axis, and orbital eccentricity of the secondary star. Results indicate that, Earth-like objects, with substantial amounts of water, can form in the habitable zone of the primary star. Simulations also indicate that, by transferring angular momentum from the secondary star to protoplanetary objects, the giant planet of the system plays a key role in the radial mixing of these bodies and the water contents of the final terrestrial planets. We will discuss the results of our simulation and show that the formation of habitable planets in binary-planetary systems is more probable in binaries with moderate to large perihelia.Comment: 27 pages, 11 figures, submitted for publicatio

Predictions for the correlation between giant and terrestrial extrasolar planets in dynamically evolved systems

The large eccentricities of many giant extrasolar planets may represent the endpoint of gravitational scattering in initially more crowded systems. If so, the early evolution of the giant planets is likely to be more restrictive of terrestrial planet formation than would be inferred from the current, dynamically quiescent, configurations. Here, we study statistically the extent of the anti-correlation between giant planets and terrestrial planets expected in a scattering model. We use marginally stable systems of three giant planets, with a realistic range of planetary masses, as a simple model for the initial conditions prior to scattering, and show that after scattering the surviving planets reproduce well the known extrasolar planet eccentricities beyond a > 0.5 AU. By tracking the minimum periastron values of all planets during the evolution, we derive the distribution of orbital radii across which strong perturbations (from crossing orbits) are likely to affect low mass planet formation. We find that scattering affects inner planet formation at orbital separations less than 50% of the final periastron distance of the innermost massive planet in approximately 30% of the realizations, and can occasionally influence planet formation at orbital separations less than 20% of the final periastron distance of the innermost massive planet. The domain of influence of the scattering massive planets increases as the mass differential between the massive planets decreases. Observational study of the correlation between massive and terrestrial extrasolar planets in the same system has the potential to constrain the origin of planetary eccentricity.Comment: 8 pages, 8 figures, 1 table, accepted for publication in Ap

Adult judgments of children’s pain and fear during venipuncture: The impact of adult and child sex

Background: Low levels of agreement between caregiver and child reports of acute pain are well documented. Aims: This study builds on prior research through exploring factors that may contribute to low caregiver–child concordance. Specifically, the study examined the influence of adult and child sex on adult judgments of children’s pain and fear during venipuncture and examined whether trait parental pain catastrophizing, empathy, and anxiety predicted judgment accuracy. Methods: Using a judgment study paradigm, 160 participants (82 women) viewed 20 10-s video clips of children (10 boys, 10 girls) undergoing venipuncture and rated each child’s pain and fear. Adults’ ratings were compared to the children’s own ratings. Adults completed measures of trait parental pain catastrophizing, dispositional empathy, and trait anxiety. Results: Adults accurately judged boys’ pain and fear significantly more often than that of girls. Further, adults underestimated and overestimated girls’ pain and overestimated girls’ fear significantly more frequently than that of boys. No effects of adult sex or adult by child sex interactions emerged. Parental pain catastrophizing significantly predicted underestimation of girls’ pain, with adults who engaged in more catastrophizing being less likely to underestimate girls’ pain. The variables did not predict adult judgment of child pain for women and men separately and did not predict adult judgment of child fear when examined by adult sex, child sex, or both combined. Conclusions: Child sex influences adult pain and fear judgments, with girls being more vulnerable to inaccurate assessment than boys. Higher levels of parental pain catastrophizing may buffer against adults’ propensities to underestimate girls’ pain

Sex differences in experimental pain among healthy children: A systematic review and meta-analysis

Sex differences in response to experimental pain are commonly reported in systematic reviews in the adult literature. The objective of the present research was to conduct a systematic review and meta-analysis of sex differences in healthy children's responses to experimental pain (eg, cold pressor, heat pain, pressure pain) and, where possible, to conduct analyses separately for children and adolescents. A search was conducted of electronic databases for published papers in English of empirical research using experimental pain tasks to examine pain-related outcomes in healthy boys and girls between 0 and 18 years of age. Eighty articles were eligible for inclusion and were coded to extract information relevant to sex differences. The systematic review indicated that, across different experimental pain tasks, the majority of studies reported no significant differences between boys and girls on pain-related outcomes. However, the meta-analysis of available combined data found that girls reported significantly higher cold pressor pain intensity compared to boys in studies where the mean age of participants was greater than 12 years. Additionally, a meta-analysis of heat pain found that boys had significantly higher tolerance than girls overall, and boys had significantly higher heat pain threshold than girls in studies where the mean age of participants was 12 years or younger. These findings suggest that developmental stage may be relevant for understanding sex differences in pain