A crucial reckoning was initiated when the COVID-19 pandemic began to expose and intensify long-standing racial/ethnic health inequities, all while various sectors of society pursued racial justice reform. As a result, there has been a contextual shift towards broader recognition of systemic racism, and not race, as the shared foundational driver of both societal maladies. This confluence of issues is of particular relevance to Black populations disproportionately affected by the pandemic and racial injustice. In response, institutions have initiated diversity, equity, and inclusion (DEI) efforts as a way forward. This article considers how the dual pandemic climate of COVID-19-related health inequities and the racial justice movement could exacerbate the “time and effort tax” on Black faculty to engage in DEI efforts in academia and biomedicine. We discuss the impact of this “tax” on career advancement and well-being, and introduce an operational framework for considering the interconnected influence of systemic racism, the dual pandemics, and DEI work on the experience of Black faculty. If not meaningfully addressed, the “time and effort tax” could contribute to Black and other underrepresented minority faculty leaving academia and biomedicine – consequently, the very diversity, equity, and inclusion work meant to increase representation could decrease it.

We report key learning from the public health management of the first two confirmed cases of COVID-19 identified in the UK. The first case imported, and the second associated with probable person-to-person transmission within the UK. Contact tracing was complex and fast-moving. Potential exposures for both cases were reviewed, and 52 contacts were identified. No further confirmed COVID-19 cases have been linked epidemiologically to these two cases. As steps are made to enhance contact tracing across the UK, the lessons learned from earlier contact tracing during the country's containment phase are particularly important and timely.

In this paper, we revisit our previous work in which we derive an effective macroscale description suitable to describe the growth of biological tissue within a porous tissue-engineering scaffold. The underlying tissue dynamics is described as a multiphase mixture, thereby naturally accommodating features such as interstitial growth and active cell motion. Via a linearization of the underlying multiphase model (whose nonlinearity poses a significant challenge for such analyses), we obtain, by means of multiple-scale homogenization, a simplified macroscale model that nevertheless retains explicit dependence on both the microscale scaffold structure and the tissue dynamics, via so-called unit-cell problems that provide permeability tensors to parameterize the macroscale description. In our previous work, the cell problems retain macroscale dependence, posing significant challenges for computational implementation of the eventual macroscopic model; here, we obtain a decoupled system whereby the quasi-steady cell problems may be solved separately from the macroscale description. Moreover, we indicate how the formulation is influenced by a set of alternative microscale boundary conditions.

Mini-sabbaticals are formal short-term training and educational experiences away from an investigator’s home research unit. These may include rotations with other research units and externships at government research or regulatory agencies, industry and non-profit programs, and training and/or intensive educational programs. The National Institutes of Health have been encouraging training institutions to consider offering mini-sabbaticals, but given the newness of the concept, limited data are available to guide the implementation of mini-sabbatical programs. In this paper, we review the history of sabbaticals and mini-sabbaticals, report the results of surveys we performed to ascertain the use of mini-sabbaticals at Clinical and Translational Science Award hubs, and consider best practice recommendations for institutions seeking to establish formal mini-sabbatical programs.

We derive an effective macroscale description for the growth of tissue on a porous scaffold. A multiphase model is employed to describe the tissue dynamics; linearisation to facilitate a multiple-scale homogenisation provides an effective macroscale description, which incorporates dependence on the microscale structure and dynamics. In particular, the resulting description admits both interstitial growth and active cell motion. This model comprises Darcy flow, and differential equations for the volume fraction of cells within the scaffold and the concentration of nutrient, required for growth. These are coupled with Stokes-type cell problems on the microscale, incorporating dependence on active cell motion and pore scale structure. The cell problems provide the permeability tensors with which the macroscale flow is parameterised. A subset of solutions is illustrated by numerical simulations.

The use of sexed semen in dairy and beef cattle production provides a number of benefits at both farm and industry levels. There is an increasing demand for dairy and beef products across the globe, which will necessitate a greater focus on improving production efficiency. In dairy farming, there is surplus production of unwanted male calves. Male dairy calves increase the risk of dystocia compared with heifer calves, and as an unwanted by-product of breeding with conventional semen, they have a low economic value. Incorporating sexed semen into the breeding programme can minimise the number of unwanted male dairy calves and reduce dystocia. Sexed semen can be used to generate herd replacements and additional heifers for herd expansion at a faster rate from within the herd, thereby minimising biosecurity risks associated with bringing in animals from different herds. Furthermore, the use of sexed semen can increase herd genetic gain compared with use of non-sorted semen. In dairy herds, a sustainable breeding strategy could combine usage of sexed semen to generate replacements only, and usage of beef semen on all dams that are not suitable for generating replacements. This results in increased genetic gain in dairy herd, increased value of beef output from the dairy herd, and reduced greenhouse gas emissions from beef. It is important to note, however, that even a small decrease in fertility of sexed semen relative to conventional semen can negate much of the economic benefit. A high fertility sexed semen product has the potential to accelerate herd expansion, minimise waste production, improve animal welfare and increase profitability compared with non-sorted conventional semen.

On behalf of my Company, which manufactures the RAE Head-up Display Equipment referred to in K. J. Holden's paper in the December 1964 issue of the Journal (pp 833-6), I would like to correct some misunderstandings which seem to exist and to amplify certain statements in this otherwise interesting and informative contribution to the techniques of instrument displays.

Dr. Holden states: “The essence of the (RAE) display is an attempt to reproduce the appearance of the runway as it would appear to the pilot.” This statement is incorrect as the flight director symbol to which he refers, is made up of a “target spot” (a’) and associated director lines (a) in Fig. 1. This symbol is a pure integrated flight director and is not and never has been intended to represent the runway.

Background: Cognitive impairment is highly prevalent in individuals with end stage kidney disease (ESKD) undergoing hemodialysis. The cause is not understood. Our overall hypothesis is that repetitive cerebral hypoperfusion during hemodialysis contributes to accelerated cognitive dysfunction in this patient population. Methods: All participants underwent a baseline assessment with the KINARM, a robotic device that provides quantitative metrics of the sensorimotor control of the upper limb in humans. For patients undergoing hemodialysis, BtO2 was monitored during one dialysis session per week. Follow up KINARM assessment was done at 3 months. Results: To date, 7 patients have completed baseline testing, with 3 being re-evaluated at 3 months. At baseline, patients were impaired on of the 8 tasks, with the exception of a test of working memory. There was a variable correlation between hemodynamics (e.g. blood pressure and heart rate), fluid removal, and BtO2 levels. At 3 months, the 3 patients improved on the majority of the performance metrics assessed with the KINARM. Conclusions: The KINARM is a feasible instrument to measure cognitive dysfunction in individuals with ESKD. In a small cohort, there is improvement in neurocognitive function 3 months after the initiation of dialysis.

The somatic muscle cells of the parasitic nematode Ascaris suum possess GABA receptors that gate chloride conductances in a similar fashion to the mammalian GABAA receptor subtype. These receptors mediate muscle relaxation and are the site of action of the anthelmintic piperazine. The properties of this receptor differ from the properties of the GABA-gated chloride receptors in the mammalian host, in particular they are not as sensitive to mammalian GABA receptor antagonists such as bicuculline and picrotoxin. Using two-electrode intracellular electrophysiological recording techniques from Ascaris muscle cells, we have tested the potency of a series of azole derivatives for their ability to block the chloride-dependent GABA response. The lead compound, SN606078, 2-(2,6-dichloro-4-trifluromethylphenyl)-4-(4,5-dicyano-lH-imidazol-2-yl)-2H-l,2,3-triazoIe, and 4 structurally related compounds reversibly blocked the conductance increase elicited by 30 μM GABA with IC50s of less than 10 μM. SN606078 (10 μM) decreased the slope of the dose-response curve for GABA, suggesting a non-competitive mechanism of action. In two-electrode voltage clamp experiments, 10μM SN606078 blocked the outward current elicited by 20 μM GABA in a voltage-dependent manner with 72 ± 2% inhibition at −20 mV and 49±6% inhibition at −40 mV. These observations indicate that SN606078 may act as an open-channel blocker of the GABA-gated chloride channel in A. suum.

The external and internal structure of the spines of Squalus acanthias are described. Internally the spines consist of a series of dentine cones laid down one within the other. This series is reflected in the external structure by bands of pigment associated with ridges of enamel. The latter are proved to be annual.

The use of the spines for age determination is discussed and the growth parameters and growth curves calculated. The results obtained differ from those of previous authors, whose work is critically discussed.

Whilst employed at the Royal Naval Hospital, Plymouth, I have been kindly granted facilities for the investigation of marine bacteria by Dr. E. J. Allen, Director of the Marine Biological Laboratories, and although the pressure of other duties has made progress extremely slow the experience obtained with different media will perhaps be of use to future workers.

5-HT is a candidate for the excitatory transmitter at the neuromuscular junction in trematodes including Fasciola hepatica. This study has determined the response of a muscle strip preparation from Fasciola hepatica to 5-HT and a range of agonists that distinguish between the vertebrate receptor 5-HT subtypes. 5-HT increased the resting tone and the rhythmic activity of the muscle strip. Of the 19 compounds tested, only 10 had an effect similar to 5-HT and all but 2 of these were tryptamine compounds. 5-HT was more potent than tryptamine whilst 4-OH-tryptamine had no effect, suggesting that the response is mediated by a 5-HT rather than a tryptamine receptor. 5-Fluorotryptamine and 5-carboxyamidotryptamine were the most potent agonists. 8-OH-DPAT also mimicked the effect of 5-HT, though less potently. Assuming that these agents elicit their response through a common receptor, this suggests the presence of a 5-HT receptor with similar properties in terms of agonist recognition as the vertebrate 5-HT1 class of receptor involved in controlling Fasciola muscle motility.

Detailed descriptions of cardiacgeometry and architecture are necessary for examining andunderstanding structural changes to the myocardium that are theresult of pathologies, for interpreting the results ofexperimental studies of propagation, and for use as athree-dimensional orthotropically anisotropic model for thecomputational reconstruction of propagation during arrhythmias.Diffusion tensor imaging (DTI) provides a means to reconstructfibre and sheet orientation throughout the ventricles. Wereconstruct and quantify canine cardiac architecture in selectedregions of the left and right ventricular free walls and theinter-ventricular septum. Fibre inclination angle rotates smoothlythrough the wall in all regions, from positive in the endocardiumto negative in the epicardium. However, fibre transverse and sheetangles show large variability in basal regions. Additionally,regions where two populations (positive and negative) of sheetstructure merge are identified. From these data, we conclude thata single DTI-derived atlas model of ventricular architectureshould be applicable to modelling propagation in wedges from theequatorial and apical left ventricle, and allow comparisons toexperimental studies carried out in wedge preparations. However,due to inter-individual variability in basal regions, individual(rather than atlas) DTI models of basal wedges or of the wholeventricles will be required.

We have studied the temperature dependence of CER spectra of layered InGaAs QWRs and QDCs and found strain-induced splitting of lh and hh states occur in both InGsAs and GaAs layers. By fitting experimental data using Varshni law and Bose-Einstein type relation, various parameters are obtained, which are similar to those of bulk GaAs. We pointed out that a caution must be excised when extracting the electron-phonon interaction parameters by subtracting the thermal dilation part from the experimental data of the embedded semiconductor microstructures because in these structures the temperature-induced lattice-dilation may produce additional strain besides the lattice mismatch.