Sites of Biosynthesis of Outer and Inner Membrane Proteins of Neurospora crassa Mitochondria

Outer and inner membranes of Neurospora crassa mitochondria were separated by the combined swelling, shrinking, sonication procedure. Membranes were characterized by electron microscopy and by marker enzyme activities. A red carotenoid pigment was found to be concentrated in the outer membrane. The inner mitochondrial membrane was resolved into about 20 protein bands on polyacrylamide gel electrophoresis, whereas the outer membrane shows essentially one single protein band. Only negligible incorporation of radioactive amino acids occurs into outer membrane when isolated mitochondria are synthesizing polypeptide chains. In agreement with this observation labeling of outer membrane protein is almost entirely blocked, when whole Neurospora cells are incubated with radioactive amino acids in the presence of cycloheximide, an inhibitor of cytoplasmic protein synthesis. Finally, the essential electrophoretic protein band from outer membrane does not become labeled when mitochondria are incubated with radioactive amino acids either in vitro or in vivo in the presence of cycloheximide. It is concluded that the vast majority, if not all, of the outer membrane protein is synthesized by the cytoplasmic system and that polypeptide chains formed by the mitochondrial ribosomes are integrated into the inner mitochondrial membrane

A mixed methods evaluation of a program exploring predeath grief and loss for carers of people with rarer dementias

Objectives: Predeath grief conceptualizes complex feelings of loss experienced for someone who is still living and is linked to poor emotional well-being. The Road Less Travelled program aimed to help carers of people with rarer dementias identify and process predeath grief. This study evaluated the feasibility, acceptability, and preliminary effectiveness of this program. Design: Pre–post interventional mixed methods study. Setting: Online videoconference group program for carers across the UK held in 2021. Participants: Nine family carers of someone living with a rare form of dementia. Eight were female and one male (mean age 58) with two facilitators. Intervention: The Road Less Travelled is an online, facilitated, group-based program that aims to help carers of people with rarer dementias to explore and accept feelings of grief and loss. It involved six fortnightly 2-hour sessions. Measurements: We collected measures for a range of well-being outcomes at baseline (T1), post-intervention (T2), and 3 months post-intervention (T3). We conducted interviews with participants and facilitators at T2. Results: Participant attendance was 98% across all sessions. Findings from the semistructured interviews supported the acceptability of the program and identified improvements in carer well-being. Trends in the outcome measures suggested an improvement in quality of life and a reduction in depression. Conclusion: The program was feasible to conduct and acceptable to participants. Qualitative reports and high attendance suggest perceived benefits to carers, including increased acceptance of grief, and support the need for a larger-scale pilot study to determine effectiveness

Very High-Energy Gamma-Ray Observations of PSR B1509-58 with the CANGAROO 3.8m Telescope

The gamma-ray pulsar PSR B1509-58 and its surrounding nebulae have been observed with the CANGAROO 3.8m imaging atmospheric Cherenkov telescope. The observations were performed from 1996 to 1998 in Woomera, South Australia, under different instrumental conditions with estimated threshold energies of 4.5 TeV (1996), 1.9 TeV (1997) and 2.5 TeV (1998) at zenith angles of ~30 deg. Although no strong evidence of the gamma-ray emission was found, the lowest energy threshold data of 1997 showed a marginal excess of gamma-ray--like events at the 4.1 sigma significance level. The corresponding gamma-ray flux is calculated to be (2.9 +/- 0.7) * 10^{-12}cm^{-2}s^{-1} above 1.9 TeV. The observations of 1996 and 1998 yielded only upper limits (99.5% confidence level) of 1.9 * 10^{-12}cm^{-2}s^{-1} above 4.5 TeV and 2.0 * 10^{-12}cm^{-2}s^{-1} above 2.5 TeV, respectively. Assuming that the 1997 excess is due to Very High-Energy (VHE) gamma-ray emission from the pulsar nebula, our result, when combined with the X-ray observations, leads to a value of the magnetic field strength ~5 micro G. This is consistent with the equipartition value previously estimated in the X-ray nebula surrounding the pulsar. No significant periodicity at the 150ms pulsar period has been found in any of the three years' data. The flux upper limits set from our observations are one order of magnitude below previously reported detections of pulsed TeV emission.Comment: Accepted to publication in Astrophys. Journal, 25 pages, 2 figure

A Dynamic Model of Unemployment with Migration and Delayed Policy Intervention

The purpose of this paper is to build and analyse a model of unemployment, where jobs search is open to both natives and migrant workers. Markets and government intervention respond jointly to unemployment when creating new jobs. Full employment of resources is the focal point of policy action, stimulating vacancy creation. We acknowledge that policy is implemented with delays, and capture labour market outcomes by building a non-linear dynamic system. We observe jobs separation and matching, and extend our model to an open economy with migration and delayed policy intervention meant to reduce unemployment. We analyse the stability behaviour of the resulting equilibrium for our dynamic system, including models with Dirac and weak kernels. We simulate our model with alternative scenarios, where policy action towards jobs creation considers both migration and unemployment, or just unemployment

The contours of a new urban world? Megacity population growth and density since 1975

The problems posed by rapid and large-scale urbanisation are manifold, and are recognised in the UN’s New Urban Agenda; a declaration of intent that aims to meet such challenges head-on facilitated by the systematic tracking and analysis of global urban growth and change. In this context, the release in 2016 of new small area Global Human Settlement Layer (GHSL) data was said to represent a unique opportunity to facilitate comparative global analyses of urban change dynamics and, perhaps somewhat idealistically, move forward progressive planning agendas. We therefore focus on population growth and density in 30 major urban agglomerations using the GHSL in order to shed light on the scale and extent of global urbanisation over the past four decades and to interrogate the potential role of the GHSL in tracking urban change

Magnetic Photon Splitting: the S-Matrix Formulation in the Landau Representation

Calculations of reaction rates for the third-order QED process of photon splitting in strong magnetic fields traditionally have employed either the effective Lagrangian method or variants of Schwinger's proper-time technique. Recently, Mentzel, Berg and Wunner (1994) presented an alternative derivation via an S-matrix formulation in the Landau representation. Advantages of such a formulation include the ability to compute rates near pair resonances above pair threshold. This paper presents new developments of the Landau representation formalism as applied to photon splitting, providing significant advances beyond the work of Mentzel et al. by summing over the spin quantum numbers of the electron propagators, and analytically integrating over the component of momentum of the intermediate states that is parallel to field. The ensuing tractable expressions for the scattering amplitudes are satisfyingly compact, and of an appearance familiar to S-matrix theory applications. Such developments can facilitate numerical computations of splitting considerably both below and above pair threshold. Specializations to two regimes of interest are obtained, namely the limit of highly supercritical fields and the domain where photon energies are far inferior to that for the threshold of single-photon pair creation. In particular, for the first time the low-frequency amplitudes are simply expressed in terms of the Gamma function, its integral and its derivatives. In addition, the equivalence of the asymptotic forms in these two domains to extant results from effective Lagrangian/proper-time formulations is demonstrated.Comment: 19 pages, 3 figures, REVTeX; accepted for publication in Phys. Rev.

Industrial work placement in higher education: a study of civil engineering student engagement

For civil engineering undergraduates, the opportunity to spend a period of time in formal industrial work placement provides an invaluable learning experience. This paper reviews student engagement with short-term industrial placement and provides analysis of questionnaires (n=174) returned by undergraduates studying civil engineering at four Higher Education Institutes (HEI’s) in the West of Scotland. The data captures industrial placement statistics, employability skill-sets and presents brief testimonies from students. Whilst the journey to becoming a professional civil engineer is undoubtedly enhanced by short-term placement clear opportunities exist for HEI’s to affect and change existing pedagogical discourse. Commentary is likely to resonate beyond civil engineering and serve as a timely reminder of the need to re-invigorate academia / industry curriculum partnerships

Hydrodynamic modelling of protein conformation in solution: ELLIPS and HYDRO

The last three decades has seen some important advances in our ability to represent the conformation of proteins in solution on the basis of hydrodynamic measurements. Advances in theoretical modeling capabilities have been matched by commensurate advances in the precision of hydrodynamic measurements. We consider the advances in whole-body (simple ellipsoid-based) modeling—still useful for providing an overall idea of molecular shape, particularly for those systems where only a limited amount of data is available—and outline the ELLIPS suite of algorithms which facilitates the use of this approach. We then focus on bead modeling strategies, particularly the surface or shell–bead approaches and the HYDRO suite of algorithms. We demonstrate how these are providing great insights into complex issues such as the conformation of immunoglobulins and other multi-domain complexes

Three Millisecond Pulsars in FERMI LAT Unassociated Bright Sources

We searched for radio pulsars in 25 of the non-variable, unassociated sources in the Fermi LAT Bright Source List with the Green Bank Telescope at 820 MHz. We report the discovery of three radio and gamma-ray millisecond pulsars (MSPs) from a high Galactic latitude subset of these sources. All of the pulsars are in binary systems, which would have made them virtually impossible to detect in blind gamma-ray pulsation searches. They seem to be relatively normal, nearby (<=2 kpc) millisecond pulsars. These observations, in combination with the Fermi detection of gamma-rays from other known radio MSPs, imply that most, if not all, radio MSPs are efficient gamma-ray producers. The gamma-ray spectra of the pulsars are power-law in nature with exponential cutoffs at a few GeV, as has been found with most other pulsars. The MSPs have all been detected as X-ray point sources. Their soft X-ray luminosities of ~10^{30-31} erg/s are typical of the rare radio MSPs seen in X-rays.Comment: Accepted for publication in ApJ Letter

All-particle cosmic ray energy spectrum measured by the HAWC experiment from 10 to 500 TeV

We report on the measurement of the all-particle cosmic ray energy spectrum with the High Altitude Water Cherenkov (HAWC) Observatory in the energy range 10 to 500 TeV. HAWC is a ground based air-shower array deployed on the slopes of Volcan Sierra Negra in the state of Puebla, Mexico, and is sensitive to gamma rays and cosmic rays at TeV energies. The data used in this work were taken from 234 days between June 2016 to February 2017. The primary cosmic-ray energy is determined with a maximum likelihood approach using the particle density as a function of distance to the shower core. Introducing quality cuts to isolate events with shower cores landing on the array, the reconstructed energy distribution is unfolded iteratively. The measured all-particle spectrum is consistent with a broken power law with an index of $-2.49\pm0.01$ prior to a break at $(45.7\pm0.1$) TeV, followed by an index of $-2.71\pm0.01$. The spectrum also respresents a single measurement that spans the energy range between direct detection and ground based experiments. As a verification of the detector response, the energy scale and angular resolution are validated by observation of the cosmic ray Moon shadow's dependence on energy.Comment: 16 pages, 11 figures, 4 tables, submission to Physical Review