Factors that influence career progression among postdoctoral clinical academics: a scoping review of the literature

Background: The future of academic medicine is uncertain. Concerns regarding the future availability of qualified and willing trainee clinical academics have been raised worldwide. Of significant concern is our failure to retain postdoctoral trainee clinical academics, who are likely to be our next generation of leaders in scientific discovery. / Objectives: To review the literature about factors that may influence postdoctoral career progression in early career clinical academics. / Design: This study employed a scoping review method. Three reviewers separately assessed whether the articles found fit the inclusion criteria. / Data sources: PubMed, Scopus, Web of Science and Google Scholar (1991–2015). / Article selection: The review encompassed a broad search of English language studies published anytime up to November 2015. All articles were eligible for inclusion, including research papers employing either quantitative or qualitative methods, as well as editorials and other summary articles. / Data extraction: Data extracted from included publications were charted according to author(s), sample population, study design, key findings, country of origin and year of publication. / Results: Our review identified 6 key influences: intrinsic motivation, work–life balance, inclusiveness, work environment, mentorship and availability of funding. It also detected significant gaps within the literature about these influences. / Conclusions: Three key steps are proposed to help support postdoctoral trainee clinical academics. These focus on ensuring that researchers feel encouraged in their workplace, involved in collaborative dialogue with key stakeholders and able to access reliable information regarding their chosen career pathway. Finally, we highlight recommendations for future research

Dynamical effects of the neutrino gravitational clustering at Planck angular scales

We study the CMB anisotropy induced by the non-linear perturbations in the massive neutrino density associated to the non-linear gravitational clustering proceses. Our results show that for the neutrino fraction in agreement with that indicated by the astroparticle and nuclear physics experiments and a cosmological accreting mass comparable with the mass of known clusters, the angular resolution and the sensitivity of the CMB anisotropy measurements from the Planck surveyor will allow the detection of the dynamical effects of the neutrino gravitational clustering.Comment: 40 pages and 12 figures, submitted to ApJ (14 March 2002

Spectrum of Sizes for Perfect Deletion-Correcting Codes

One peculiarity with deletion-correcting codes is that perfect $t$-deletion-correcting codes of the same length over the same alphabet can have different numbers of codewords, because the balls of radius $t$ with respect to the Levenshte\u{\i}n distance may be of different sizes. There is interest, therefore, in determining all possible sizes of a perfect $t$-deletion-correcting code, given the length $n$ and the alphabet size~$q$. In this paper, we determine completely the spectrum of possible sizes for perfect $q$-ary 1-deletion-correcting codes of length three for all $q$, and perfect $q$-ary 2-deletion-correcting codes of length four for almost all $q$, leaving only a small finite number of cases in doubt.Comment: 23 page

Jet-Induced Emission-Line Nebulosity and Star Formation in the High-Redshift Radio Galaxy 4C41.17

The high redshift radio galaxy 4C41.17 consists of a powerful radio source in which previous work has shown that there is strong evidence for jet-induced star formation along the radio axis. We argue that nuclear photoionization is not responsible for the excitation of the emission line clouds and we construct a jet-cloud interaction model to explain the major features revealed by the data. The interaction of a high-powered jet with a dense cloud in the halo of 4C41.17 produces shock-excited emission-line nebulosity through ~1000 km/s shocks and induces star formation. The CIII to CIV line ratio and the CIV luminosity emanating from the shock, imply that the pre-shock density in the line-emitting cloud is high enough (~1-10 cm^-3) that shock initiated star formation could proceed on a timescale of order a few x 10^6 yrs, well within the estimated dynamical age of the radio source. Broad (FWHM ~ 100 - 1400 km/s) emission lines are attributed to the disturbance of the gas cloud by a partial bow--shock and narrow emission lines (FWHM ~ 500 - 650 km/s) (in particular CIV) arise in precursor emission in relatively low metallicity gas. The implied baryonic mass ~ 8 \times 10^{10} solar masses of the cloud is high and implies that Milky Way size condensations existed in the environments of forming radio galaxies at a redshift of 3.8. Our interpretation of the data provides a physical basis for the alignment of the radio, emission-line and UV continuum images in some of the highest redshift radio galaxies and the analysis presented here may form a basis for the calculation of densities and cloud masses in other high redshift radio galaxies.Comment: 18 pages, 5 figures; uses astrobib.sty and aaspp4.sty. Better versions of figures available via anonymous from ftp://mso.anu.edu.au:pub/pub/geoff/4C41.1

5-10 GeV Neutrinos from Gamma-Ray Burst Fireballs

A gamma-ray burst fireball is likely to contain an admixture of neutrons, in addition to protons, in essentially all progenitor scenarios. Inelastic collisions between differentially streaming protons and neutrons in the fireball produce muon neutrinos (antineutrinos) of ~ 10 GeV as well as electron neutrinos (antineutrinos) of ~ 5 GeV, which could produce ~ 7 events/year in kilometer cube detectors, if the neutron abundance is comparable to that of protons. Photons of ~ 10 GeV from pi-zero decay and ~ 100 MeV electron antineutrinos from neutron decay are also produced, but will be difficult to detect. Photons with energies < 1 MeV from shocks following neutron decay produce a characteristic signal which may be distinguishable from the proton-related MeV photons.Comment: 4 pages, latex, 1 figure, aps style files. Final version, accepted in Phys.Rev.Lett., 6/22/2000; some clarifications in the text, same conclusion

The Low Redshift Lyman Alpha Forest in Cold Dark Matter Cosmologies

We study the physical origin of the low-redshift Lyman alpha forest in hydrodynamic simulations of four CDM cosmologies. Our main conclusions are insensitive to the cosmological model but depend on our assumption that the UV background declines at low redshift. We find that the expansion of the universe drives rapid evolution of dN/dz (the number of absorbers per unit z) at z > 1.7, but that at lower redshift the fading of the UV background counters the influence of expansion, leading to slow evolution. At every redshift, weaker lines come primarily from moderate fluctuations of the diffuse, unshocked IGM, and stronger lines originate in shocked or radiatively cooled gas of higher overdensity. However, the neutral hydrogen column density associated with structures of fixed overdensity drops as the universe expands, so an absorber at z = 0 is dynamically analogous to an absorber with neutral hydrogen column density 10 to 50 times higher at z = 2-3. We find no clear distinction between lines arising in "galaxy halos" and lines arising in larger scale structures; however, galaxies tend to lie near the dense regions of the IGM that produce strong Lyman alpha lines. The simulations provide a unified physical picture that accounts for the most distinctive observed properties of the low redshift Lyman alpha forest: (1) a sharp transition in the evolution of dN/dz at z ~ 1.7, (2) stronger evolution for absorbers of higher equivalent width, (3) a correlation of increasing Lyman alpha equivalent width with decreasing galaxy impact parameter, and (4) a tendency for stronger lines to arise in close proximity to galaxies while weaker lines trace more diffuse large scale structure. (Abridged)Comment: 57 pages, 18 figures, submitted to Ap

Efficiency of Electron-Positron Pair Productionby Neutrino Flux from Accretion Disk of a Kerr Black Hole

Dominant processes of neutrino production and neutrino-induced \ep-pair production are examined in the model of a disk hyper-accreting onto a Kerr black hole. The efficiency of plasma production by a neutrino flux from the disk, obtained for the both cases of presence and absence of a magnetic field, is found to be no more than several tenths of percent and, therefore, not enough for the origin of cosmological gamma-ray bursts.Comment: 8 pages, 1 figur

The clinical academic workforce of the future: a cross-sectional study of factors influencing career decision-making among clinical PhD students at two research-intensive UK universities

OBJECTIVES: To examine clinical doctoral students’ demographic and training characteristics, career intentions, career preparedness and what influences them as they plan their future careers. DESIGN AND SETTING: Online cross-sectional census surveys at two research-intensive medical schools in England in 2015–2016. PARTICIPANTS: All medically qualified PhD students (N=523) enrolled at the University of Oxford and University College London were invited to participate. We report on data from 320 participants (54% male and 44% female), who were representative by gender of the invited population. MAIN OUTCOME MEASURES: Career intentions. RESULTS: Respondents were mainly in specialty training, including close to training completion (25%, n=80), and 18% (n=57) had completed training. Half (50%, n=159) intended to pursue a clinical academic career (CAC) and 62% (n=198) were at least moderately likely to seek a clinical lectureship (CL). However, 51% (n=163) had little or no knowledge about CL posts. Those wanting a CAC tended to have the most predoctoral medical research experience (χ2 (2, N=305)=22.19, p=0.0005). Key reasons cited for not pursuing a CAC were the small number of senior academic appointments available, the difficulty of obtaining research grants and work-life balance. CONCLUSIONS: Findings suggest that urging predoctoral clinicians to gain varied research experience while ensuring availability of opportunities, and introducing more flexible recruitment criteria for CL appointments, would foster CACs. As CL posts are often only open to those still in training, the many postdoctoral clinicians who have completed training, or nearly done so, do not currently gain the opportunity the post offers to develop as independent researchers. Better opportunities should be accompanied by enhanced career support for clinical doctoral students (eg, to increase knowledge of CLs). Finally, ways to increase the number of senior clinical academic appointments should be explored since their lack seems to significantly influence career decisions