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BNT162b2 mRNA and ChAdOx1 nCOV-19 adenoviral vector vaccines have been rapidly rolled out in the UK from December, 2020. We aimed to determine the factors associated with vaccine coverage for both vaccines and documented the vaccine effectiveness of the BNT162b2 mRNA vaccine in a cohort of health-care workers undergoing regular asymptomatic testing.

ABSTRACTIn this paper, we introduce readers to the Indigenous Wellbeing of Boys and Men project, a 4-year research collaboration between scholars from the Universities of Manitoba and British Columbia and Fisher River Cree Nation (Ochékwi Sipi). We overview the research design of the project, paying particular attention to the foundational strategies that informed the research process. These strategies included, embedding the project within an Indigenous paradigm, rooting it within the place-specific context of Fisher River Cree Nation, and creating a community-wide and intergenerational dialogue about Indigenous physical cultures and masculinities. We then examine the first phase of the project, which involved sharing circles, to illustrate how these strategies informed the research process. We argue that this design enabled critical insights on the role that physical culture can potentially play in maintaining and revitalising place-specific Indigenous masculinities. This paper brings the burgeoning scholarship in Indigenous methodologies and Indigenous masculinities into conversation with the work in physical cultural studies and, in so doing, makes important contributions to each disciplinary area.

ABSTRACTAn experimental study has been conducted to evaluate the effect of static strain aging (bake hardening) on the yield strength and yield strength asymmetry in torsion and torsion/reverse torsion tests on a low-carbon martensitic steel. It is shown that vastly different strain aging responses are observed in the forward and reverse portions of the torsion test following strain aging. While the yield stresses can be described phenomenologically by classic segregation kinetics, the observed asymmetry in the kinetics and magnitude of strain aging call into question the simple interpretation of dislocation de-pinning. This is further emphasised by the fact that strain aging modifies the apparent work hardening rate in the reverse loading tests.

The objective of these studies was to investigate the efficacy of an intravaginal triptorelin acetate (TA) gel as an ovulation-inducing agent in mares. In Exp. 1, 24 mares were blocked using a combination of parity and age and randomly assigned to 1 of 3 treatment groups: 5 mL TA gel (TA5), 10 mL TA gel (TA10), or 5 mL vehicle gel only (CON). Following the appearance of a follicle ≥ 25 mm, a blood sample was obtained for measurement of LH from each mare every 24 h until treatment administration. When a follicle ≥ 35 mm was observed, treatments were administered intravaginally. Following treatment, blood samples were collected for measurement of LH and ovaries were scanned via ultrasonography every 12 h until 48 h post-ovulation. Mares in both TA5 and TA10 tended (P= 0.08) to experience a brief surge in LH by 12 h post-treatment. There was a treatment by time interaction (P< 0.005). The interval from treatment to ovulation was not different between groups (P> 0.05).. We hypothesized that duration of elevated LH was not sufficient to induce ovulation in most mares. In Exp. 2, 23 mares were blocked by parity/age and randomly assigned to 3 treatment groups: the CON (n= 7) and TA5 (n= 8) treatment groups remained the same, but the TA10 treatment was split into two 5-mL doses administered 24 h apart (TA5×2; n= 8). Blood collection and ultrasonography occurred every 12 h on detection of a follicle ≥ 25 mm in diameter. Once a follicle ≥ 35 mm was detected, treatment was administered and ultrasonography and blood collection for measurement of LH occurred every 6 h until 48 h post-ovulation to get a more robust characterization of the effect of TA on LH and a more accurate timeframe in which ovulation was occurring. Mares in both TA5 and TA5×2 had an increase (P< 0.05) in LH by 6 h post-treatment, which was declining by 12 h post-treatment. Following the second dose in TA5×2, another rise in LH occurred, but to a lesser magnitude (P> 0.05). compared with the initial dose. Again there was a treatment by time interaction (P< 0.005) and in Exp. 2 the interval from treatment to ovulation was shorter in TA5 (61.5 ± 8.8 h) and TA5×2 (61.5 ± 9.6 h) compared with CON (123.1 ± 21.7 h; P< 0.01). In Exp. 2, administration of TA gel increased LH concentrations and hastened the interval from treatment to ovulation in mares, without an advantage in the timing of ovulation noted between the 5 or 10-mL doses, or administration of two 5-mL doses given 24 h apart.

Numerical modelling methods (e.g. finite element) can provide accurate descriptions of long-range temperature fields in laser or electron-beam melting processes, however the high computational costs at part-scale make them unsuitable for process modelling in additive manufacturing (AM). Alternative methods such as semi-analytical solutions based on a moving heat source reduce the computational expense but at the cost of unrealistic assumptions. Radiation, temperature-dependent physical properties and latent heat are not considered in the semi-analytical approach but can have a significant effect on the thermal history. In this study, the error associated with each of these contributions are assessed against the conduction-only semi-analytical solution for a range of processing parameters for surface melting on solid Ti-6Al-4V. The semi-analytical model is then “enhanced” using results from finite element simulations to better account for the heat transfer in the AM process.

AA5xxx aluminium alloys are used in the automotive and packaging industries owing to their high strength and ductility. The addition of Sc and Zr to these alloys has shown promise for improving high temperature stability and therefore broadening the range of applications. This high temperature stability is due to the formation of fine Al3(Sc, Zr) precipitates during aging. In this work, two twin-belt cast Al–3Mg alloys, one with 0·4 Sc and the other without Sc, were annealed at 300 and 400°C. Hardness, tensile yield stress and electrical resistivity measurements were used to examine the evolution of microstructure and strength of the alloys. These results were then utilised to develop a yield stress–precipitation model to describe simultaneous precipitation hardening and recovery.

(S)-CPW399 (2b) is a novel, potent, and subtype-selective AMPA receptor full agonist that, unlike (S)-willardiine and related compounds, in mouse cerebellar granule cells, stimulated an increase in [Ca²⁺]i, and induced neuronal cell death in a time- and concentration-dependent manner. Compound 2b appears to be a weakly desensitizing, full agonist at AMPA receptors and therefore represents a new pharmacological tool to investigate the role of AMPA receptors in excitotoxicity and their molecular mechanisms of desensitization.

Adenosine kinase (AK) inhibitors can enhance adenosine levels and potentiate adenosine receptor activation. As the AK inhibitors 5′ iodotubercidin (ITU) and 5‐amino‐5′‐deoxyadenosine (NH2dAdo) are nucleoside analogues, we hypothesized that nucleoside transporter subtype expression can affect the potency of these inhibitors in intact cells.Three nucleoside transporter subtypes that mediate adenosine permeation of rat cells have been characterized and cloned: equilibrative transporters rENT1 and rENT2 and concentrative transporter rCNT2. We stably transfected rat C6 glioma cells, which express rENT2 nucleoside transporters, with rENT1 (rENT1‐C6 cells) or rCNT2 (rCNT2‐C6 cells) nucleoside transporters.We tested the effects of ITU and NH2dAdo on [3H]‐adenosine uptake and conversion to [3H]‐adenine nucleotides in the three cell types. NH2dAdo did not show any cell type selectivity. In contrast, ITU showed significant inhibition of [3H]‐adenosine uptake and [3H]‐adenine nucleotide formation at concentrations 100 nMin rENT1‐C6 cells, while concentrations 3 μMwere required for C6 or rCNT2‐C6 cells.Nitrobenzylthioinosine (NBMPR; 100 nM), a selective inhibitor of rENT1, abolished the effects of nanomolar concentrations of ITU in rENT1‐C6 cells.This study demonstrates that the effects of ITU, but not NH2dAdo, in whole cell assays are dependent upon nucleoside transporter subtype expression. Thus, cellular and tissue differences in expression of nucleoside transporter subtypes may affect the pharmacological actions of some AK inhibitors.

Two three-dimensional receptor interaction models for EAAT substrates and nontransportable inhibitors have been developed, and new glutamate (Glu) and aspartate (Asp) analogues have been synthesized. The analogues 1a and 3 represent novel lead compounds for the development of EAAT substrates and nontransportable inhibitors, selective for EAATs over iGluRs, as possible neuroprotective agents useful to minimize the progression of chronic or acute neurodegenerative diseases. The role played by the protonatable amine function in the interaction with EAATs has been discussed.

Uptake by the liver of the organic cation and essential nutrient choline is required for the hepatic synthesis of phosphatidylcholine. Uptake of other organic cations is also important for the metabolism and secretion of numerous endobiotics and drugs. Although a high affinity mammalian hepatic choline transporter has been kinetically defined, it has not been previously identified. We have developed stable transfectants of BALB/3T3 cells, using a murine member of the organic cation transporter gene family (mOct1/Slc22a1), and used these cells to characterize the transport of the organic cation choline and model organic cation tetraethylammonium (TEA). Functional expression of mOct1/Slc22a1 in BALB/3T3 cells confers the saturable, temperature-dependent uptake of choline with a K(m) of 42 micrometer, and uptake of TEA with a K(m) of 43 micrometer. We subsequently used our cell culture uptake system to kinetically define in HepG2 cells a high affinity choline uptake process, which transports choline with a K(m) similar to that of mOct1/Slc22a1 protein. We also demonstrated that organic cation transport by mOct1/Slc22a1 is inhibited by several organic cations, and that the gene is expressed in the perinatal period, at a time when phosphatidylcholine synthesis increases.We conclude that mOct1/Slc22a1 encodes a high affinity mammalian hepatic choline/organic cation transporter. This transporter may be important for hepatic phosphatidylcholine synthesis, and for the metabolism and secretion of many organic cationic drugs.

Abstract: The process of isothermal solidification during transient liquid-phase (TLP) bonding in a ternary system is analyzed. In the most usual situation, and in contrast to the binary case, the composition of the liquid is required to change continuously as solidification proceeds. If the solubilities and/or diffusion coefficients of the two solutes are very different, the solidification stage is clearly divided into two parabolic regimes, the first dominated by the “faster” solute and the second by the slower of the two. In extreme cases, full solidification may not be realized in experimentally accessible times.

Abstract: Transient liquid phase (TLP) bonding is finding use in applications that require high thermal, electrical, chemical, and/or mechanical stability such as in electrical connectors, turbine vanes, and metal-matrix composites. To date, much work has been done to quantify the behavior of binary material combinations during the rate-limiting isothermal solidification step of TLP bonding. However, this model is not general enough to accurately predict the behavior of more complex multicomponent alloys and interlayers. A model is presented here that begins to account for the behavior in such systems.

Protein Ser/Thr phosphatase 5 is a 58-kDa protein containing a catalytic domain structurally related to the catalytic subunits of protein phosphatases 1, 2A, and 2B and an extended N-terminal domain with three tetratricopeptide repeats. The activity of this enzyme is stimulated 4-14-fold in vitro by polyunsaturated fatty acids and anionic phospholipids. The structural basis for lipid activation of protein phosphatase 5 was examined by limited proteolysis and site-directed mutagenesis. Trypsinolysis removed the tetratricopeptide repeat domain and increased activity to approximately half that of lipid-stimulated, full-length enzyme. Subtilisin removed the tetratricopeptide repeat domain and 10 residues from the C terminus, creating a catalytic fragment with activity that was equal to or greater than that of lipid-stimulated, full-length enzyme. Catalytic fragments generated by proteolysis were no longer stimulated by lipid, and degradation of the tetratricopeptide repeat domain was decreased by association with lipid. A truncated mutant missing 13 C-terminal residues was also insensitive to lipid and was as active as full-length, lipid-stimulated enzyme. These results suggest that the C-terminal and N-terminal domain act in a coordinated manner to suppress the activity of protein phosphatase 5 and mediate its activation by lipid. These regions may be targets for the regulation of protein phosphatase 5 activity in vivo.

It may take a long time to make a machine as complex as the human brain and render it intelligent by loading in the right software, but it will happen. There are significant projects which will change man's life style considerably. A photograph of the author is included.

The NATO Science Committee's funding of programs for civil science began in the mid 1950s, and the Committee continues to support and foster science in the Alliance. The Science Committee conducted a symposium in order to review the current state of non-military science in the Soviet Union. A report on that symposium.

Thirteen out of 36 strains of Rivulariaceae were found to be able to produce hairs. In all 13 strains, abundant hair increase occurred under conditions of phosphate deficiency. Fe deficiency also led to hair formation in 8 strains, and Mg deficiency in one strain, but Ca, Mo and SO4 deficiences had no such effect. Although the presence of combined nitrogen had a marked effect on the trichome morphology of the heterocystous strains, it reduced hair formation in only three strains, and the effect was only slight. Addition of the missing element to deficient cultures with hairs always eventually led to the loss of the hair. Two field materials were also studied, in crude culture. Both showed increased hair development with decreasing phosphate concentration.

A set of overlapping peptides corresponding to the L1, E6, and E7 proteins of human papilloma virus 16 was tested for their ability to bind to major histocompatibility complex class I molecules and to stimulate cytotoxic T-lymphocyte (CTL) responses in vitro. A class I binding assay using intact RMA-S cells showed that 20 of the 99 human papilloma virus peptides bound to H-2Kb and/or Db molecules. Fifteen of the 20 class I-binding peptides stimulated primary CTL responses, whereas peptides that were negative in the binding assay failed to do so. Peptide-induced CTLs recognized the immunizing peptide very efficiently, requiring no more than 1-10 nM peptide for target cell lysis. However, two observations were made that have important implications for the design of peptide-based vaccines for inducing CTLs. (i) Not all major histocompatibility complex-binding peptides that contained known motifs characteristic of naturally processed peptides induced CTLs. (ii) The efficiency of CTL lysis was strongly decreased when the size of the target peptide differed by only one amino acid residue from that of the immunizing peptide. We conclude that peptides chosen for vaccination must correspond in length to naturally processed peptides.

We have purified from chicken forebrain a membrane glycoprotein that is enriched in purified synaptic membranes and has an apparent mol.wt. of 22 800 in 15% sodium dodecyl sulphate/polyacrylamide gels. This molecule was compared with rat and human brain Thy-1 glycoproteins purified by the same procedure in order to determine whether it could be a homologue of Thy-1. Although polyvalent heterologous antisera raised against the rat and chicken molecules showed no immunological cross-reactivity with the other glycoprotein, a great deal of physical and chemical similarity was demonstrated between the chicken glycoprotein and rat Thy-1. Their apparent molecular weights, subcellular localization and amino acid and amino sugar compositions are very similar. C.d. spectra show that both molecules contain predominantly a beta-sheet and structure with no detectable alpha-helix. Electrophoretic analysis of the CNBr-cleaved molecules under reducing and non-reducing conditions shows that both molecules contain intramolecular disulphide bridges. Taken together these results suggest that the chicken brain glycoprotein is an immunologically distinct homologue of the mammalian Thy-1 glycoproteins.

Expression of the driving forces for oxygen transfer as chemical potential differences leads to a more correct formulation of the oxygen transfer equation. The results explain many anomalies in the measurements of the oxygen transfer coefficient kLa.

An arachidonic acid-stimulated Ser/Thr phosphatase activity was detected in soluble extracts prepared from rat pituitary clonal GH4C1 cells, rat or bovine brain, and bovine heart. The enzyme activity was purified to homogeneity from bovine brain as a monomer with a Mr of 63,000 and a specific activity of 32 nmol of Pi released per min/mg of protein when assayed in the presence of 10 microM phosphocasein in the absence of lipid. Arachidonic acid stimulated activity 4-14-fold, with half-maximal stimulation at 50-100 microM, when assayed in the presence of a variety of phosphosubstrates including casein, reduced carboxamidomethylated and maleylated lysozyme, myelin basic protein, and histone. Oleic acid, linoleic acid, and palmitoleic acid also stimulated activity; however, saturated fatty acids and alcohol or methyl ester derivatives of fatty acids did not significantly affect activity. The lipid-stimulated phosphatase was identified as the bovine equivalent of protein phosphatase 5 or a closely related homolog by sequence analysis of proteolytic fragments generated from the purified enzyme. When recombinant rat protein phosphatase 5 was expressed as a cleavable glutathione S-transferase fusion protein, the affinity-purified thrombin-cleaved enzyme exhibited a specific activity and sensitivity to arachidonic acid similar to those of the purified bovine brain enzyme. These results suggest that protein phosphatase 5 may be regulated in vivo by a lipid second messenger or another endogenous activator.

An FEL injector is under development based on the photoemission gun and superconducting radio frequency (srf) technologies established at CEBAF. The injector will deliver ∼10 MeV CW electron beams having a transverse normalized rms emittance <11 π mm mrad and a longitudinal rms emittance <35 π deg-keV with up to 200 pC charge within 8 ps (4σ) at a repetition rate of 24.95 MHz or 2.495 MHz. Its performance has been modeled using a version of PARMELA with a point-by-point space charge algorithm. The details of modeling and the simulated performance of the injector are presented.

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Experiments were conducted with 300 growing-finishing swine in confinement on slotted floors to study the effects of adding .11% Mg from MgO to a ground yellow dent corn-soybean meal (soybean seeds without hulls, solvent-extracted ground) fortified diet (table 1). Also studied were the effects of crowding, i.e., 6.86 sq ft vs4.57 sq ft per pig (.63 sq m vs.43 sq m). The higher population density reduced average daily gains (P < .01) in both tests, and increased feed/gain ratio (P< .05) in Experiment I. Pigs docked vslittermates with tails had similar performance in both population densities, with or without added Mg. In the high density populations, a significantly lower percentage of the pigs were observed to be standing and a higher percentage lying than in the low density populations. These differences were greater as the experiments progressed and the pigs increased in size. Magnesium did not significantly affect the percentage of pigs standing, lying, eating, or drinking in either the high or the low density groups.

The generalised least squares, maximum likelihood, Bain-Antle 1 and 2, and two mixed methods of estimating the parameters of the two-parameter Weibull distribution are compared. The comparison is made using (a) the observed relative efficiency of parameter estimates and (b) themean squared relative error in estimated quantiles, to summarize the results of 1000 simulated samples of sizes 10 and 25. The results are that: generalised least squares is the best method of estimating the shape parameter ß the best method of estimating the scale parameter a depends onthe size of ß for quantile estimation maximum likelihood is best Bain-Antle 2 is uniformly the worst of the methods.

This controlled, randomised, double blind study compared whether glossopharyngeal nerve block and intravenous morphine administered peri‐operatively, decreased pain following elective adult tonsillectomy and uvulopalatoplasty more than morphine alone. Sixteen of 30 patients undergoing uvulopalatoplasty and 38 of 78 patients having tonsillectomy received bilateral glossopharyngeal nerve blocks, using bupivacaine 0.5% and adrenaline 1:200 000, or no intervention. There were no differences in postoperative analgesic consumption between the two groups. Visual analogue pain scores measured during swallowing, in the recovery room and on the ward postoperatively, were significantly less overall in uvulopalatoplasty patients who had received a block (p = 0.004). This difference was not found for tonsillectomy. We found no significant differences between groups, in pain scores recorded during the first 5 days at home. We conclude that glossopharyngeal block does not improve analgesia following tonsillectomy although there is short‐lived benefit following uvulopalatoplasty.

Background In the Grampian region early anistreplase trial (GREAT), domiciliary thrombolysis by general practitioners was associated with a halving of one year mortality compared with hospital administration. However, after completion of the trial and publication of the results, the use of this treatment by general practitioners declined sharply. Objective To increase the proportion of eligible patients receiving timely thrombolytic treatment from their general practitioners. Setting Practices in Grampian located ≥ 30 minutes' travelling time from Aberdeen Royal Infirmary, where patients with suspected acute myocardial infarction were referred after being seen by general practitioners. Audit standard A call-to-needle time of 90 minutes, as proposed by the British Heart Foundation (BHF). Methods Findings of this audit of prehospital management of acute myocardial infarction were periodically fed back to the participating doctors, when practice case reviews were also conducted. Results Of 414 administrations of thrombolytic treatment, 146 (35%) were given by general practitioners and 268 (65%) were deferred until after hospital admission. Median call-to-needle times were 45 (94% ≤ 90) and 145 (7% ≤ 90) minutes, respectively. Survival at one year was improved with prehospital compared with hospital thrombolysis (83% v 73%; p &lt; 0.05). The proportion of patients receiving thrombolytic treatment from their general practitioners did not increase during the audit. Conclusions In practices ≥ 30 minutes from hospital, the BHF audit standard was readily achieved if general practitioners gave thrombolytic treatment, but not otherwise. Knowledge of the benefits of early thrombolysis, and feedback of audit results, did not lead to increased prehospital thrombolytic use. Additional incentives are required if general practitioners are to give thrombolytic treatment.

A graphical method is described depicting the relationship between the physical oxygen transfer rate and microbial oxygen uptake rate in order to help determine the conditions under which growth will not be limited by oxygen.

The adsorption of beef plasma on asbestos markedly shortens the one-stage prothrombin time of the plasma when tissue thromboplastin is used as the throm boplastic agent. This adsorption on asbestos does not affect the Russell viper venom time of the plasma. The adsorbed plasma exhibits increased factor VII activity over that of the original plasma. An eluate can be prepared from the asbestos which prolongs the one-stage prothrombin time sof beef and human plasma.

Three alkylating agents, HN2 (methyl-bis(betachlorethyl)amine), chlorambucil (p-(di-2-chlorethylamino)-phenylbutyric acid), and busulphan (1,4-dimethanesulphonoxybutane) were studied with regard to their effects on leukocyte and red cell production in dogs. This was assessed by estimation of the peripheral blood leukocyte and reticulocyte changes as well as alterations in the plasma iron, Fe59disappearance rate, plasma iron turnover, and red cell incorporation of radioactive iron. The two chlorethylamines had a similar effect on both leukocyte and red cell production. The effect on peripheral leukocyte counts was evident in 24 hours and the reticulocyte response indicated maximum interference with erythropoiesis on the third to seventh day following the drug. The effect of busulphan on both granulocytes and lymphocytes was slower to appear and slowly progressive. A difference in ferrokinetic pattern between the chlorethylamines and busulphan was also noted. The dissimilarity in ferrokinetic patterns may indicate a difference not only in mechanism of these agents on proliferating normoblasts but also in the inhibitory effects on the acceptance of iron by the red cell precursors and other body iron pools.

THE SOLUTION TO THE WORLD'S FOOD PROBLEMS. "WHO WILL EAT?", by Michael Allaby. Tom Stacy Ltd., London, 1972, ISBN 085468 153 1, 252 pp. (£2.90.)MAN AND HIS ENVIRONMENT: FOOD, by Lester R. Brown, Overseas Development Council and Gail W. Finsterbusch, The Urban Institute. Published by Harper & Row, Publishers, New York and London, 1972, 208 pp. (£1.50.)MEDICINE TAKERS, PRESCRIBERS AND HOARDERS by Karen Dunnell and Ann Cartwright. Routledge & Kegan Paul, 182 pp. (£3.25.)SOCIAL BEHAVIOUR, NATURAL RESOURCES AND THE ENVIRONMENT, Burch, Cheek and Taylor (eds.). Harper & Row, New York, 1972.ENVIRONMENTAL QUALITY ANALYSIS: THEORY AND METHOD IN THE SOCIAL SCIENCES, edited by A. V. Kneese and B. T. Bowen, Johns Hopkins Press for Resources for the Future Inc., Baltimore and London, 1972. ix + 408 pp. (£5.70.)AIR SAMPLING INSTRUMENTS, 4th Edition-American Conference of Governmental Industrial Hygienists (A.C.G.I.H.), P.O. Box 1937, Cincinatti, Ohio. xxviii + 549 pp. ($12.50.)A DEVELOPING STRATEGY FOR THE WEST MIDLANDS, Report of the West Midland Regional Study, 1971.

Summary In potassium-deficient barley, the arginine content was increased three-fold above that of controls, while the amines agmatine and putrescine (derived from arginine) increased about 10-fold and 40-fold respectively. From the 6th–7th leaf stage onwards, fluctuations in the level of putrescine were negatively correlated with changes in temperature, while those of arginine and agmatine level were positively correlated. Both a mass action effect of arginine and temperature-induced changes in enzyme activity are postulated as contributory factors towards putrescine accumulation.

A lasertron (a microwave "triode" with an RF output cavity and an RF modulated laser to illuminate a photocathode) is a possible high power RF amplifier for TeV linear colliders. As the first step toward building a 35 MW, S-band lasertron for a proof of principle demonstration, a 400 kV dc diode is being designed with a GaAs photocathode, a drift-tube and a collector. After some cathode life tests are made in the diode, an RF output cavity will replace the drift tube and a modelocked, frequency-doubled, Nd:YAG laser, modulated to produce a 1 us-long comb of 60 ps pulses at a 2856 MHz rate, will be used to illuminate the photocathode to make an RF power source out of the device. This paper discusses the plans for the project and includes some results of numerical simulation studies of the lasertron as well as some of the ultra-high vacuum and mechanical design requirements for incorporating a photocathode.

The denger of blindness from the direct rays of the sun, which appears to have been generally recognized not only by the medical profession but also by the laity of the past generation, is apparently unrecognized to-day. During the recent eclipse, many might have been seen looking at it with the naked eye. It is not uncommon for patients to tell the physician, as a proof of strong vision, that they can look steadily at bright lights, and even at the sun without blinking. Children not infrequently undertake competitive trials to see which can gaze longest and most steadily at the sun.In many of the recent smaller works on ophthalmology the subject of sun-blindness is not mentioned. Nettleship, Lawson, Williams, Schweiger and De Wecker refer to the possibility of blindness being caused by flashes of lightning, by the bright glare from snow and from a too prolonged gaze at