Recent changes to US research funding are having far-reaching consequences that imperil the integrity of science and the provision of care to vulnerable populations. Resisting these changes, the BJPsych Portfolio reaffirms its commitment to publishing mental science and advancing psychiatric knowledge that improves the mental health of one and all.

Unregulated care aides provide most of the direct care to nursing home residents. We previously reported the first demographic profile of care aides in Western Canada through the Translating Research in Elder Care (TREC) longitudinal research program (2007–2022) in applied health services. Here we describe demographic, health, and work life characteristics of aides from 91 nursing homes in Western Canada. Demographics and work life varied significantly across health regions and facility owner-operator models. Our longitudinal cohort of aides from Alberta and Winnipeg had higher emotional exhaustion (a negative attribute), professional efficacy (a positive attribute), and experience of dementia-related responsive behaviours from residents. Overall, results indicate little improvement or worsening of care aide health and quality of work life. Coupled with limited provincial or national initiatives for workforce planning and training of these workers, this signals a long-term care system ill-prepared to care effectively for Canada’s aging population.

Complete BVRCIC light curves of V1187 Her were obtained in May 2017 at the Dark Sky Observatory in North Carolina with the 0.81-m reflector of Appalachian State University. Earlier, spectra were taken at the Dominion Astrophysical Observatory with the 1.8-m telescope. The spectral type was found to be F8±1 V (6250 K), so the binary is of solar-type. V1187 Her was previously identified as a low amplitude (V < 0.2 mag), short period, overcontact eclipsing binary (EW) with a period of 0.310726 d. Strikingly, despite its low amplitude, the early light curves show total eclipses (eclipse duration ≍31.5 minutes), which is a characteristic of an extreme mass ratio binary. A period study covering 11 years reveals a continuous period decrease dP/dt=–4.7×10–9 d yr–1. The multi-band Wilson-Devinney light curve solution gives a fill-out of 79% and a mass ratio of only 0.0440±0.0001. There is a cool spot region on the secondary component, which is 400 K hotter than the primary. The inclination is only 66.85±0.05 despite the system’s total eclipses.

We investigated the hydrodynamic properties of cephalopod shell sculpture in two ways: 1) flow visualization experiments with sculptured shells; and 2) application of drag coefficient data for simple geometric bodies to cephalopod shells. Results of this work suggest:

1) the hydrodynamic effect of shell sculpture depends primarily on the size of the sculptural elements relative to the size of the shell and on the positions of sculpture elements on the shell and relative to each other.

2) sculpture is detrimental to swimming (reduces hydrodynamic efficiency) if it exceeds the height of the lower part of the shell's boundary layer.

3) sculpture is advantageous to swimming (increases efficiency) if it remains immersed in the boundary layer and induces premature conversion to turbulent boundary layer flow. To be hydrodynamically optimal, small shells (diam ≈ 10 cm) must have rough (sculptured) surfaces, whereas large shells (diam ≈ 100 cm) require smooth surfaces. Thus, in order to maintain maximum efficiency throughout life, the ontogeny of small individuals, or species, should be characterized by progressive roughening of the shell, while large forms should become increasingly smooth. Such allometries are observed among many ammonoids.

4) sculpture always has an effect on the flow around a cephalopod shell. In some species this effect was probably negligible, while in others, those with compressed shells especially, it was probably of major importance. In these species, sculpture appears to have functioned primarily to increase swimming ability.

The Antarctic Plateau provides the best terrestrial sites for infrared (IR) and submillimetre (sub-mm) astronomy. In this paper we examine the relative importance of temperature, aerosol content and precipitable water vapour to determine which parameters have the greatest influence on atmospheric transmission and sky brightness. We use the atmospheric modelling program MODTRAN to model the observed sky spectrum at the South Pole from the near-IR to the sub-mm. We find that temperature and aerosol content determine the quality of near-IR observing conditions, aerosol content is the determining factor in the mid-IR up to 20 μm, while at longer wavelengths, including the sub-mm, it is the water vapour content that matters. Finding a location where aerosol levels are minimised is a key constraint in determining the optimum site on the Antarctic Plateau for an IR observatory.

During the past decade, the number known shallow-amplitude, yet totally eclipsing, extreme-mass-ratio binaries has increased from one (AW UMa, which is now in doubt) to about a dozen. Statistics are accumulating that will tell us the nature of these once rare systems. These individual interacting field binaries are believed to be the progenitors of FK Comae-type fast-rotating subgiants, which are similar to the cluster stars called ‘variable blue stragglers.’ We review our recent observations and new analyses of the individual systems, V409 Hya, GSC 1283 0053 Ori, GSC 2537 520 CVn, using the 2007 Wilson Code and summarize results from our previous observations (V802 Aql, V902 Sgr) and those from the literature (e.g., CK Boo, GR Vir, HV Aqr, UY UMa, EM Pis, CU Tau, TV Mus) to disclose a preliminary picture of the character of this interesting class of binary stars.

The ommatidia of the lateral eye of the horseshoe crab, Limulus polyphemus, undergo rhythmic changes in structure that are driven by diurnal lighting and efferent neural activity from a circadian clock in the brain. This study uses cytochemical probes to investigate the cytoskeletal elements mediating these responses and to develop models for their control. Antibodies to actin and phalloidin, a specific F-actin probe, label the rhabdom of lateral eye ommatidia, the cone cells of the ommatidial aperture, the ommatidial sheath, and the peripheral regions of the photoreceptor (retinular cell) cytoplasm. These probes also label the rhabdomere of ventral photoreceptors. Antibodies to tubulin label the eccentric cell dendrite and soma in each lateral eye ommatidium, the cone cells of the aperture, and the peripheral retinular cell cytoplasm. Models are proposed for the cytoskeletal mechanisms involved in controlling aperture and rhabdom shape, pigment movement, and shedding of rhabdomeral membrane.

A method is described in which a liquid suspension of sheep faeces is used as an inoculum in the in vitro determination of digestibility of feedingstuffs for ruminants. The modified method was applied to 21 samples of grass, ten of lucerne, and a variety of other food materials. The results correlated closely (r = 0·98) with the in vivo digestibilities, and the relationship between in vitro and in vivo digestibilities was represented by the equation: in vivo digestibility = in vitro digestibility × 1·003.

In each of two experiments, eight silages supplemented with concentrates containing a high proportion of either starch or digestible fibre were given to rumen-cannulated sheep. The silages constituted c. 65% of the total dry matter and differed widely in chemical composition, reflecting differences in the extent of fermentation in the silo.

Rumen pH was lower (P < 0·01 and P < 0·001 for Expts 1 and 2 respectively) and the concentration of total volatile fatty acids (VFA) in the rumen was higher (P < 0·001 for Expt 2) for the starchy concentrate. Silages differed in their effects on ruminal proportions of acetate (P < 0·001 and P < 0·01 for Expts 1 and 2 respectively) and, inversely, of propionate (P < 0·001 for Expt 1). There was evidence of a strong relationship between the molar proportion of propionate in the rumen and the concentration of lactic acid in the silage. The results indicate that the production of propionate during the metabolism of silage lactic acid by the rumen microbial population was the predominant influence on rumen fermentation pattern.

It is suggested that this relationship is the basis of some of the differences in milk production reported for silages showing restricted as opposed to extensive fermentation.

A total of 21 rumen-cannulated wether sheep and six rumen-cannulated Ayrshire cows were used in a series of experiments to investigate fermentation in the rumen in animals given silage diets and the nominal metabolism of silage lactic acid. Dietary experiments with sheep (three experiments) and cows (two experiments) given diets consisting of formic acid–preserved perennial ryegrass (Lolium perenne) silages, in some cases with supplements of rolled barley, were conducted to investigate the ruminal concentrations of lactic acid and of volatile fatty acids (VFA) after feeding. Ingestion of silage was followed by a short-lived peak in lactic acid concentration in the rumen and by a subsequent increase in the concentration of propionate or propionate and butyrate. Butyrate production was more evident in cattle than in sheep. Taken as an average over a 6 h period of sampling the proportions (m-mol/mol total VFA) of acetate, propionate and butyrate in the rumen in animals given silage alone were typically 590–600, 210–250 and 70–150 respectively. When silage was supplemented with barley, in both sheep and cattle, the proportion of propionate was reduced and the proportion of butyrate was increased. In one experiment with sheep these changes in fermentation pattern were shown to be accompanied by an increase in the number of rumen protozoa from 2·78×105/ml to 18·66·105/ml (P <0·01). However, in a subsequent experiment it was shown that defaunation led to an increase in the proportion of butyrate in the rumen.

Twelve estimates were also made with sheep of the metabolism of lactic acid infused into the rumen in a single dose of 20–50 g. These experiments showed that both (L+) and DL-lactio acid were metabolized equally rapidly with a half-life of approximately 25 min. In faunated animals the major products of fermentation were propionate with a small amount of butyrate. In defaunated animals lactate metabolism was slowed and the major product of fermentation was butyrate.

In vitro studies of lactate fermentation were carried out using strained liquor and isolated bacterial and protozoal fractions from the rumen of sheep receiving silage diets. The rates of lactate disappearance (μg/mg protein/h) were 50 and 22·2 for the rumen liquor and bacterial fraction, respectively, which were significantly (P <0·05, n = 5) less than the rate of 294·7 for the protozoal fraction. Rumen liquor, bacterial and protozoal fractions yielded a similar mixture of fermentation end-products, propionate accounting for approximately 60% of the VFA produced.

The results are discussed in relation to the metabolism of silage lactic acid in the rumen, the production of VFA and the yield of ATP for microbial cell synthesis. It is concluded that the pathways of lactate fermentation are regulated by the rumen microbial population and that protozoa may have an important role in the regulation of lactate fermentation.

The tissue copper concentrations of Black Najdi sheep at the Hofuf Agricultural Research Centre (HARC) are reported. Lambs suffering from a delayed neonatal ataxia had low concentrations of copper in blood, liver and kidney, consistent with a diagnosis of copper deficiency, which was supported by histological examination of their brains and spinal cords.

Low concentrations of copper and high concentrations of molybdenum and sulphate in forages produced at the HARC appear to contribute to the high incidence of neonatal ataxia observed there.

The parenteral administration of 40 mg of copper to pregnant ewes improved the viability and weight increases of lambs over lambs born to untreated control ewes, even though all lambs had received an injection of 20 mg of copper soon after birth.

The provision of supplementary barley to the lambs running with their mothers and with access to lucerne hay increased their growth and blood copper concentrations over animals restricted to the hay diet.

The blood copper, haemoglobin and packed cell volumes of lambs born to ewes maintained on Rhodes grass were significantly lower than lambs born to ewes given lucerne, all ewes having received copper during pregnancy. This effect was attributed to the low copper and high molybdenum and sulphate content of Rhodes grass (Chloris gayana).

A total of 15 rumen-cannulated sheep and four rumen-cannulated goats (Expt 3) were used in five latin square experiments designed to investigate the effects of carbohydrate supplements on ruminal ammonia concentration in animals given grass silage diets. In Expt 1 barley supplements were given at the same time, 1 h before or 2 h before a meal of silage. The treatments were designed to alter the synchronization between energy release from fermentation of barley and ammonia release from the degradation of silage N compounds. As compared with the unsupplemented control diet, barley supplements reduced (P < 0–05) rumen ammonia concentration and increased (P < 0–01) the number of total protozoa, but the time at which barley was given was without effect. In Expt 2 animals receiving silage or silage-barley diets were defaunated chemically. This treatment led to a 20–25 % reduction in rumen ammonia concentration. In Expt 3 supplements of maize starch, glucose and sucrose were compared. Mean ammonia concentrations were 231 mg/1 for the control unsupplemented diet and 205, 155 and 160 mg/1 (S.E. 21) for the starch, glucose and sucrose treatments. Corresponding numbers of protozoa were 7–7, 15–1, 6–1 and 6–3 x 10s/ml (S.E. 1–8). In Expt 4 the diets were unsupplemented silage or the same diet plus supplements of sucrose or xylose. Xylose reduced ammonia concentration more than sucrose, the values (mg/1) being 236 (control), 206 (sucrose) and 125 (xylose) (S.E. 19). There was no difference between the supplements in numbers of protozoa. Xylose induced a smaller reduction in pH, a higher (P < 0–05) proportion of acetate and a lower (P < 0–05) proportion of butyrate in rumen fluid than did sucrose. Effects of rumen pH were examined in Expt 5 where supplements of sucrose were given alone or together with NaHCO3. Rumen pH values were 6–38 for the control unsupplemented diet and 5–99, 6–28 and 6–55 (S.E. 0–06) for the diets supplemented with sucrose, sucrose plus 50 g NaHC03 and sucrose plus 100 g NaHCO3. Corresponding values for ruminal ammonia were 193, 151, 93 and 41 mg/1 (S.E. 10). Differences in VFA proportions between sucrose treatments were small and significant (P < 0–05) only for butyrate. It is concluded that there are important differences between carbohydrate sources in their effects on nitrogen metabolism in the rumen. Differences between starch and sugars appear to relate to the influence of the carbohydrates on the microbial population of the rumen, as was indicated by the differential effects of the carbohydrate sources on the number of total protozoa; differences between sugars appear to depend in part on the rates of sugar fermentation and the associated reduction in rumen pH.

Rumen ammonia levels in animals given silage diets are generally high and there appears to be considerable scope for improving the utilization of ammonia for microbial protein synthesis (Thomas & Chamberlain, 1982). Chamberlain et al. (1985) showed that supplements of sucrose were more effective than supplements of starch in reducing the rumen ammonia levels in animals given silage diets. Moreover, the effects of sucrose were increased when it was given together with sodium bicarbonate. The implication was that the sucrose supplements increased the fixation of ammonia in microbial protein through the provision of additional fermentable energy, and that this process was enhanced by the sodium bicarbonate supplements. The experiment reported here was designed to provide quantitative information on these effects and in particular to elucidate more fully the effects of sodium bicarbonate supplements on nitrogen metabolism in the rumen.

Three in vitro methods, one enzymic and two microbial, were applied satisfactorily to the determination of the dry matter digestibility of forages, but failed when applied to a variety of concentrate feeds. The microbial methods had the advantage that the proportion of weight lost from forages during the in vitro process approximated closely with their determined in vivo digestibilities.

The microbial method based on sheep faeces was as effective as that using rumen liquor in digesting ruminant feedstuff's in vitro. Since sheep faeces are readily obtained from intact animals, the faeces liquor method would seem to have a distinct advantage in use.

The aim of this study was to investigate the developmental expression of major histocompatibility complex class II (MHCII) by microglia and macrophages and their relationship to blood vessels in the retina, a representative tissue of the central nervous system. Such information is crucial to understanding the role of these cells in immune surveillance. Wholemount preparations of retinas from late embryonic, postnatal and adult rabbits were subjected to three-colour fluorescence microscopy using β2 integrin (CD18) and MHCII antibodies and biotinylated Griffonia simplicifolia B4 isolectin labelling of blood vessels. CD18+ cells consistently exhibited characteristics of macrophages or microglia in the vascularized and non-vascularized regions of the retina, respectively. At all ages, MHCII was expressed by a high proportion of cells in the vascularized region, which contained macrophage-like ‘parenchymal cells’ as well as typical perivascular macrophages. MHCII expression by ramified microglia, first detected on postnatal day 30, was lower in the peripheral retina and intermediate in the avascular region of the myelinated streak. The observed localization of MHCII+ cells in relation to blood vessels and location-dependent differences in MHCII expression point to the possibility that these cells may be distributed strategically within the retina to provide multiple lines of defence against immune challenge arriving via the retinal vasculature.

In this paper we report on the development of micromachined filters for operation at terahertz frequencies. SU8, a negative photodefinable epoxy, is used to define arrays of high aspect ratio rods which are subsequently sputter coated in gold to form the filter. We fabricate and test a filter with a fixed period but variable diameter along the length of the array. By moving the array in the terahertz beam we demonstrate the ability to mechanically tune specific filter characteristics from a single device.

We have found photometric indications that Interacting Eclipsing Binaries of early to mid F spectral type (and possibly A) have strong magnetic activity which would arise from convective atmospheres. Light curve solutions and periodicity studies revealing spots, magnetic breaking and magnetic cycles are presented in XZ CMi, V965 Cyg and V963 Cyg.