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This paper examines the impact of mobile money account ownership on farmers' participation in farmer‐based organisations (FBOs), structured market and off‐farm work. Relying on recursive bivariate probit model, our results reveal that owning a mobile money account increases the likelihood of farmers' participating in an FBO, structured market and off‐farm work by 15.4%, 33.3% and 37.5%, respectively. Furthermore, mobile money account ownership is influenced by socioeconomic and institutional factors as well as the presence of mobile money vendors within a community. Our finding calls for sustained efforts to deepen digital financial inclusion for increased participation in FBOs, structured market and off‐farm work. [ABSTRACT FROM AUTHOR]

Aims. We present near ultraviolet (NUV: 1750 - 2800 angstrom) and far ultraviolet (FUV: 1350 - 1750 angstrom) light-curves for flares on 4 nearby dMe-type stars (GJ 3685A, CR Dra, AF Psc and SDSS J084425.9+513830.5) observed with the GALEX satellite. Methods. Taking advantage of the time-tagged events recorded with the GALEX photon counting detectors, we present high temporal resolution (< 0.01 s) analysis of these UV flare data. Results. A statistical analysis of 700 s of pre-flare quiescence data for both CR Dra and SDSS J084425.9+513830.5 failed to reveal the presence of significant micro-flare activity in time bins of 0.2, 1 and 10 s intervals. Using an appropriate differential emission measure for both the quiescent and flaring state, it is possible to reproduce the observed FUV: NUV flux ratios. A major determinant in reproducing this flux ratio is found to be the value of plasma electron density during the flare. We also searched the count rate data recorded during each of the four flare events for periodicity associated with magneto-hydrodynamic oscillations in the active region coronal loops. Significant oscillations were detected during the flare events observed on all 4 stars, with periodicities found in the 30 to 40 s range. Flare oscillations with this periodicity can be explained as acoustic waves in a coronal loop of length of approximate to 10(9) cm for an assumed plasma temperature of 5-20 x 10(6) K. This suggests a loop length for these M-dwarf flares of less than 1/10th of the stellar radii. We believe that this is the first detection of non-solar coronal loop flare oscillations observed at ultraviolet wavelengths.

There is general agreement that the effect of frequency on lexical access time is roughly logarithmic, although little attention has been given to the reason for this. The authors argue that models of lexical access that incorporate a frequency-ordered serial comparison or verification procedure provide an account of this effect and predict that the underlying function directly relates access time to the rank order of words in a frequency-ordered set. For both group data and individual data, it is shown that rank provides a better fit to the data than does a function based on log frequency. Extensions to a search model are proposed that account for error rates and latencies and the effect of age of acquisition, which is interpreted as an effect of cumulative frequency.

Asymmetry is required by most numerical simulations of stellar core-collapse explosions, but the form it takes differs significantly among models. The spatial distribution of radioactive [sup.44]Ti, synthesized in an exploding star near the boundary between material falling back onto the collapsing core and that ejected into the surrounding medium (1), directly probes the explosion asymmetries. Cassiopeia A is a young (2), nearby (3), core-collapse (4) remnant from which [sup.44]Ti emission has previously been detected (5-8) but not imaged. Asymmetries in the explosion have been indirectly inferred from a high ratio of observed [sup.44]Ti emission to estimated [sup.56]Ni emission (9), from optical light echoes (10), and from jet-like features seen in the X-ray (11) and optical (12) ejecta. Here we report spatial maps and spectral properties of the [sup.44]Ti in Cassiopeia A. This may explain the unexpected lack of correlation between the [sup.44]Ti and iron X-ray emission, the latter being visible only in shock-heated material. The observed spatial distribution rules out symmetric explosions even with a high level of convective mixing, as well as highly asymmetric bipolar explosions resulting from a fast-rotating progenitor. Instead, these observations provide strong evidence for the development of low-mode convective instabilities in core-collapse supernovae., Titanium-44 is produced in Si burning in the innermost regions of the material ejected in core-collapse supernovae, in the same processes that produce Fe and [56.sup]Ni (ref. 13). The decay [...]

The flare of radiation from the tidal disruption and accretion of a star can be used as a marker for supermassive black holes that otherwise lie dormant and undetected in the centres of distant galaxies (1). Previous candidate flares (2-6) have had declining light curves in good agreement with expectations, but with poor constraints on the time of disruption and the type of star disrupted, because the rising emission was not observed. Recently, two 'relativistic' candidate tidal disruption events were discovered, each of whose extreme X-ray luminosity and synchrotron radio emission were interpreted as the onset of emission from a relativistic jet (7-10). Here we report a luminous ultraviolet-optical flare from the nuclear region of an inactive galaxy at a redshift of 0.1696. The observed continuum is cooler than expected for a simple accreting debris disk, but the well-sampled rise and decay of the light curve follow the predicted mass accretion rate and can be modelled to determine the time of disruption to an accuracy of two days. The black hole has a mass of about two million solar masses, modulo a factor dependent on the mass and radius of the star disrupted. On the basis of the spectroscopic signature of ionized helium from the unbound debris, we determine that the disrupted star was a helium-rich stellar core., When the pericentre of a star's orbit ([R.sub.p]) passes within the tidal disruption radius of a massive black hole, [R.sub.T]≅[R.sub.*][([M.sub.BH]/[M.sub.*]).sup.1/3] (where [R.sub.*] the stellar radius, [M.sub.BH] is the black-hole mass [...]

Objectives: To describe the clinical presentation, management and outcome of cases presenting with intrathoracic wooden skewers originating from the abdominal gastrointestinal tract. Materials and Methods: Clinical records of dogs presented and treated for an intrathoracic wooden skewer were reviewed from June to August 2020. Data included signalment, clinical presentation, duration of clinical signs, haematological and biochemical abnormalities, diagnostic imaging findings, surgical procedure, postoperative complications and outcome. Results: Eleven dogs were included in the study. In all cases, the foreign body was identified as a wooden skewer. The most common clinical signs were anorexia/hyporexia (n=7), vomiting/regurgitation (n=7), lethargy (n=6), pyrexia (n=4) and gait abnormalities/lameness (n=3). CT correctly identified a wooden skewer in all cases when performed (n=7). A coeliotomy combined with transdiaphragmatic thoracotomy was performed in six of 11 cases (55%), a coeliotomy combined with median sternotomy in four of 11 cases (36%) and a median sternotomy alone was performed in one case. Foreign bodies penetrated from the stomach (n=10) or the duodenum (n=1). Intrathoracic trauma was most commonly identified to the lungs (n=3) and pericardium (n=3). Complications occurred in three of 11 cases (27%), two minor and one resulting in death. Ten of the 11 cases (91%) survived to discharge. Long‐term outcome was available for seven of 11 cases (66%), all of them excellent. Clinical Significance: Despite the challenges of managing wooden skewers penetrating the thoracic cavity from the abdominal gastrointestinal tract, the majority of the patients are stable to undergo diagnostic procedures, surgical exploration and management with low morbidity and excellent short‐ and long‐term prognosis. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate whether Neoptyphodium spp. endophytes, fungal symbionts of cool-season grasses, can be selected to improve plant growth and seed yield of perennial ryegrass (Lolium perenne L.). Endophyte-infected (EI) and endophyte-free (EF) clones of 13 L. perenne genotypes, collected from native habitats with stressful environmental conditions, were evaluated in a field experiment for symbiotic effects on plant growth (herbage yield, reproductive tiller number), seed production, and seed quality parameters [1000-seed weight (TSW), germination] over 3 yr in an area with low rainfall (Halle, Germany). The results revealed high variability in endophyte effects on the investigated parameters. In seven genotypes, endophyte presence improved plant growth and seed production during the first harvest year. However, in four of these genotypes, endophyte effects were reversed in the following harvests. In the remaining six genotypes, endophyte infection reduced plant performance. The impact of the fungus on TSW was inconsistent, while seed germination was either improved or not affected by the endophyte. A positive endophyte effect was detectable for genotypes with low performance of EF clones, whereas genotypes with high-yield EF clones were not, or negatively, affected by the endophyte. Gcnotypes originating from sites exposed to flooding and periodic drought showed consistent negative endophyte effects on herbage yield and seed production. Since reduced shoot growth is a drought avoidance mechanism, further studies are needed to determine whether endophytes in these genotypes improve adaptation to drought, or represent a 'metabolic cost.' Our results indicate that some Neotyphodium endophytes have the potential to improve plant performance of L. perenne, but the selection of strains with consistent beneficial effects on plant growth is difficult., ENDOPHYTIC FUNGI of the genus Neotyphodium live in symbiosis with many cool-season grasses. The endophyte colonizes the intercellular spaces of all aerial plant parts and depends entirely on the host [...]

Objectives: To describe the outcome and complications associated with the use of caudal superficial epigastric axial pattern flaps in dogs and cats. Material and Methods: Multicentre retrospective review and descriptive study of clinical records of dogs and cats having undergone caudal superficial epigastric axial pattern flaps between 2007 and 2020. Data retrieved included signalment, aetiology of surgical defect, tumour type, presence/absence of clean surgical margins, presence/absence of post‐operative wound infection, use of peri‐ and post‐operative antibiotics, duration of anaesthesia, duration of surgery, presence and duration of hypothermia, presence and duration of hypotension, presence/absence of post‐operative surgical drain and length of caudal superficial epigastric axial pattern flap. The incidence of complications and outcomes were documented. Results: Seventy cases met the inclusion criteria; 51 dogs and 19 cats. In dogs, 67% of cases developed complications (59% minor, 8% major) and 33% had uneventful wound healing. In cats, 53% of cases developed complications, (47% minor, 5% major) and 47% had uneventful wound healing. In dogs, the percentage of cases experiencing dehiscence, necrosis, seroma, oedema and post‐operative infection was 31%, 29%, 26%, 26% and 16% respectively. In cats, this was 26%, 16%, 11%, 0% and 5% respectively. A good overall outcome was seen in 77% of dogs and 79% of cats. A poor overall outcome was seen in 4% of dogs and 0% of cats. Clinical Significance: Caudal superficial epigastric axial pattern flaps are traditionally thought more robust than other flaps, yet complication rates remain high, despite a high overall success rate. [ABSTRACT FROM AUTHOR]

Mkn 421 is a nearby active galactic nucleus dominated at all wavelengths by a very broad nonthermal continuum thought to arise from a relativistic jet seen at a small angle to the line of sight. Its spectral energy distribution peaks in the X-ray and TeV γ-ray bands, where the energy output is dominated by cooling of high-energy electrons in the jet. In order to study the electron distribution and its evolution, we carried out a dedicated multi-wavelength campaign, including extensive observations by the recently launched highly sensitive hard X-ray telescope NuSTAR, between December 2012 and May 2013. Here we present some initial results based on NuSTAR data from January through March 2013, as well as calibration observations conducted in 2012. Although the observations cover some of the faintest hard X-ray flux states ever observed forMkn 421, the sensitivity is high enough to resolve intra-day spectral variability. We find that in this low state the dominant flux variations are smooth on timescales of hours, with typical intra-hour variations of ≲ 5%. We do not find evidence for either a cutoff in the hard X-ray spectrum, or a rise towards a high-energy component, but rather that at low flux the spectrum assumes a power law shape with a photon index of approximately 3. The spectrum is found to harden with increasing brightness.

Background Clinical pathways are associated with improved adherence to clinical guidelines; however, most studies have evaluated pathways for a single intervention at a single institution. The objective of the present study was to develop and evaluate a method of measuring concordance with a population-based clinical pathway map to determine if that method could be feasible for assessing overall health system performance. Methods Patients with stage ii or iii colon cancer diagnosed in 2010 were identified, and clinical data were obtained through linkages to administrative databases. Pathway concordance was defined a priori based on receipt of key elements of the Ontario Health (Cancer Care Ontario) colorectal pathway maps. For stages ii and iii colon cancer alike, concordance was reported as the proportion of patients receiving care that followed the predefined key elements of the pathway map. Regression analysis was used to identify predictors of concordant care. Results Our study identified 816 patients with stage ii and 800 patients with stage iii colon cancer. Of the patients with stage ii disease, 70% (n = 571) received concordant care. Of the patients with stage iii disease, results showed high concordance for all key elements except receipt of chemotherapy, leading to an overall concordance rate of 39% for that cohort. Conclusions Our method of measuring concordance was feasible on a population-based level, but future studies to validate it and to develop more sophisticated methods to measure concordance in larger cohorts and various disease sites are necessary. Measurement of clinical pathway concordance on a population-based level has the potential to be a useful tool for assessing system performance. [ABSTRACT FROM AUTHOR]

Presents a study that investigated the origin of superparamagnetism in nickel oxide. Method of the study; Results and discussion; Conclusion.

Presents a study which examined the transport and structural properties of ytrrium barium[sub2]copper[sub3]oxygen[sub7-δ] thin films deposited by pulsed laser ablation. Experimental details; Results and discussion; Conclusion.

In this paper, we report the results of an X-ray monitoring campaign on the heavily obscured Seyfert galaxy, Markarian 3, carried out between the fall of 2014 and the spring of 2015 with NuSTAR, Suzaku and XMM-Newton. The hard X-ray spectrum of Markarian 3 is variable on all the time-scales probed by our campaign, down to a few days. The observed continuum variability is due to an intrinsically variable primary continuum seen in transmission through a large, but still Compton-thin column density (NH ~ 0.8-1.1 × 1024 cm-2). If arranged in a spherical-toroidal geometry, the Compton scattering matter has an opening angle ≃66°, and is seen at a grazing angle through its upper rim (inclination angle ≃70°). We report a possible occultation event during the 2014 campaign. If the torus is constituted by a system of clouds sharing the same column density, this event allows us to constrain their number (17 ± 5) and individual column density, [≃ (4.9 ± 1.5) × 1022 cm-2]. The comparison of IR and X-ray spectroscopic results with state-of-the art 'torus' models suggests that at least two-thirds of the X-ray obscuring gas volume might be located within the dust sublimation radius. We report also the discovery of an ionized absorber, characterized by variable resonant absorption lines due to He- and H-like iron. This discovery lends support to the idea that moderate column density absorbers could be due to clouds evaporated at the outer surface of the torus, possibly accelerated by the radiation pressure due to the central AGN emission leaking through the patchy absorber. [ABSTRACT FROM AUTHOR]

A computational model has been implemented that is capable of accurately predicting the flow patterns around a vortex generator. The aim in development was the resolution of small-scale flow features. By observing the progression of the vortex structure along the wing, the causes of flow separation could be ascertained. It was found that flow separation occurred when the vortex structure produced by the generators broke down. This caused a localized flow separation that, at high angles, extended to cause globalized separation and generator engulfment. The computational fluid dynamics model was tested with a wind tunnel model and found to accurately describe the aerodynamic characteristics of the wing in the unstalled and lightly stalled condition. It was found that the severity of stall, experienced by wings fitted with ramp-type vortex generators, is largely due to a feedback loop mechanism that is created by the flow being drawn through the generators by attached trailing flows. An additional consequence of this was the increase in sensitivity to Reynolds number of the wing, resulting from the addition of vortex generators. Results indicate that the knowledge of these effects could be successfully applied to other wing profiles and designs. [ABSTRACT FROM AUTHOR]

The Nuclear Spectroscopic Telescope Array (NuSTAR) is the first focusing hard X-ray mission in orbit and operates in the 3-79 keV range. NuSTAR's sensitivity is roughly two orders of magnitude better than previous missions in this energy band thanks to its superb angular resolution. Since its launch in 2012 June, NuSTAR has performed excellently and observed many interesting sources including four magnetars, two rotation-powered pulsars and the cataclysmic variable AE Aquarii. NuSTAR also discovered 3.76-s pulsations from the transient source SGR J1745-29 recently found by Swift very close to the Galactic center, clearly identifying the source as a transient magnetar. For magnetar 1E 1841-045, we show that the spectrum is well fit by an absorbed blackbody plus broken power-law model with a hard power-law photon index of ∼ 1.3. This is consistent with previous results by INTEGRAL and RXTE. We also find an interesting double-peaked pulse profile in the 25-35 keV band. For AE Aquarii, we show that the spectrum can be described by a multi-temperature thermal model or a thermal plus non-thermal model; a multi-temperature thermal model without a non-thermal component cannot be ruled out. Furthermore, we do not see a spiky pulse profile in the hard X-ray band, as previously reported based on Suzaku observations. For other magnetars and rotation-powered pulsars observed with NuSTAR, data analysis results will be soon available. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Asymmetry is required by most numerical simulations of stellar core-collapse explosions, but the form it takes differs significantly among models. The spatial distribution of radioactive 44Ti, synthesized in an exploding star near the boundary between material falling back onto the collapsing core and that ejected into the surrounding medium, directly probes the explosion asymmetries. Cassiopeia A is a young, nearby, core-collapse remnant from which 44Ti emission has previously been detected but not imaged. Asymmetries in the explosion have been indirectly inferred from a high ratio of observed 44Ti emission to estimated 56Ni emission, from optical light echoes, and from jet-like features seen in the X-ray and optical ejecta. Here we report spatial maps and spectral properties of the 44Ti in Cassiopeia A. This may explain the unexpected lack of correlation between the 44Ti and iron X-ray emission, the latter being visible only in shock-heated material. The observed spatial distribution rules out symmetric explosions even with a high level of convective mixing, as well as highly asymmetric bipolar explosions resulting from a fast-rotating progenitor. Instead, these observations provide strong evidence for the development of low-mode convective instabilities in core-collapse supernovae. [ABSTRACT FROM AUTHOR]

We present the selection and classification of over a thousand ultraviolet (UV) variable sources discovered in ∼40 deg2 of GALEX Time Domain Survey (TDS) NUV images observed with a cadence of 2 days and a baseline of observations of ∼3 years. The GALEX TDS fields were designed to be in spatial and temporal coordination with the Pan-STARRS1 Medium Deep Survey, which provides deep optical imaging and simultaneous optical transient detections via image differencing. We characterize the GALEX photometric errors empirically as a function of mean magnitude, and select sources that vary at the 5σ level in at least one epoch. We measure the statistical properties of the UV variability, including the structure function on timescales of days and years. We report classifications for the GALEX TDS sample using a combination of optical host colors and morphology, UV light curve characteristics, and matches to archival X-ray, and spectroscopy catalogs. We classify 62% of the sources as active galaxies (358 quasars and 305 active galactic nuclei), and 10% as variable stars (including 37 RR Lyrae, 53 M dwarf flare stars, and 2 cataclysmic variables). We detect a large-amplitude tail in the UV variability distribution for M-dwarf flare stars and RR Lyrae, reaching up to ∣Δm∣ = 4.6 mag and 2.9 mag, respectively. The mean amplitude of the structure function for quasars on year timescales is five times larger than observed at optical wavelengths. The remaining unclassified sources include UV-bright extragalactic transients, two of which have been spectroscopically confirmed to be a young core-collapse supernova and a flare from the tidal disruption of a star by dormant supermassive black hole. We calculate a surface density for variable sources in the UV with NUV < 23 mag and ∣Δm∣ > 0.2 mag of ∼8.0, 7.7, and 1.8 deg-2 for quasars, active galactic nuclei, and RR Lyrae stars, respectively. We also calculate a surface density rate in the UV for transient sources, using the effective survey time at the cadence appropriate to each class, of ∼15 and 52 deg-2 yr-1 for M dwarfs and extragalactic transients, respectively. [ABSTRACT FROM AUTHOR]

Purpose: The tangential-beam technique frequently presents challenges in homogeneity of radiation dose to the target. To ensure an adequate dose to the skin, a bolus is often used. Tomotherapy has already been shown to improve target conformity and homogeneity in other disease sites. Because of the tangential delivery technique and lack of flattening filter in TomoTherapy accelerators, we hypothesize that during chest wall irradiation using tomotherapy, the skin dose will be adequate without bolus.Materials and Methods: This study compares the dosimetric differences between tomotherapy chest wall irradiation and traditional linear accelerator-based tangential-beam technique. Tomotherapy treatment plans with and without bolus were compared with tangentialbeam plans. Plans were also generated for phantom studies, and point doses were measured using MOSFET dosimetry to verify the adequate skin dose. Monte Carlo simulations of static beams of both techniques were performed, and dosimetry was compared.Results: Monte Carlo simulations and measurements confirmed that beams from tomotherapy deliver a higher skin dose than a standard linear accelerator. Skin dose also increases with the incident angle of the beams.Conclusion: Because of the characteristics of the tomotherapy beam and delivery technique, chest wall treatment plans from tomotherapy showed adequate skin dose [more than 75% of prescribed planning target volume (PTV) dose] even without bolus. [ABSTRACT FROM AUTHOR]

Using eight-letter words, masked form-priming is examined with more extreme versions of transposed primes than are normally considered. Strong priming effects are observed when as few as two out of eight letters are correctly positioned within the prime, indicating that the word recognition system is surprisingly flexible with regard to letter position. Three prominent models of letter position coding are considered in light of the observed data. The comparison between models focuses on the assumptions and mechanisms within each. Strengths and weaknesses are identified for all approaches. Some evidence is found in support of differential weighting of letter positions, although the more specific question of whether it is exterior or initial letters that are most crucial to word recognition remains unresolved. [ABSTRACT FROM AUTHOR]

Contents Thirty cyclic, non-suckled Brahman cows were divided into three groups, all of which were synchronized sequentially with CIDR-B and observed continuously for 100 h to determine different behavioural oestrus signs. Twenty-four hours after implant withdrawal, all synchronized cows in the group, together with all other cows displaying oestrus, were subjected to intensive ultrasonographic observations (every 6 h for 120 h) to pinpoint the moment of ovulation. In the first group, oestrus and ovulation response was 60% (6/10), in the second 44% (4/9) showed oestrus and six ovulated, and in the third group oestrus and ovulation were 80% (8/10). Significant differences were observed between the second and third groups (p < 0.05). No differences were observed in the duration of oestrus, time when oestrus was displayed after implant withdrawal, time of ovulation and onset of oestrus, end of oestrus to ovulation, and intensity of oestrus on a point scale. The relationship between duration of oestrus and time of ovulation was r2 = 0.16. Ovulation, on average, was 32.1 ± 14.5 h after the onset of oestrus, 22.3 ± 16.5 h after the end of oestrus, and 91.8 ± 16.7 after implant withdrawal, although no significant differences were observed. One non-synchronized animal showed oestrous activity in the second group but failed to ovulate. In the third group, 8 animals showed oestrus, 4 with high concentrations of progesterone. Of the other four one ovulated. In conclusion, oestrous behaviour is not necessarily the best marker to predict the time when ovulation takes place due to variation in the length of the oestrous period and the possible integration of non-ovulatory animals into sexually active groups. [ABSTRACT FROM AUTHOR]

Contents To determine the pattern of follicular growth during oestrus and the relationship with estradiol and luteinizing hormone in ovulating and non-ovulating cows, three groups of (n = 10), thirty cyclic, Bos indicus cows were synchronized with CIDR, consecutively at 9-day intervals. Twenty-four hours after implant withdrawal, all cows synchronized in the same group with other cows displaying estrous behaviour after implant withdrawal were subjected to an intensive period of ultrasonographic observations (every 6 h for 120 h). Blood samples were taken to evaluate LH surge and 17- β estradiol. No differences were observed in follicular growth, ovulatory diameter and growth average in the three groups of synchronized cows. Cows ovulating (CO) had a better growth average in comparison with the group of cows not ovulating (CNO) (1.4 ± 0.7 mm vs 0.7 ± 0.5 mm, p < 0.06). The average time from estradiol release to LH surge was 39.3 ± 24.6 h. Differences were also observed between CO and CNO with respect to both the first concentration (27.7 ± 5.2 vs 58.6 ± 31.9, p < 0.004) and last concentration (79.3 ± 23.3 vs 99.2 ± 27.3, p < 0.05) of estradiol above 5 pg/ml. The average time from overt signs of oestrus to LH release was 8.4 ± 7.7 h. In the CNO, the increase in LH concentration was never above two SD from the basal average. In conclusion, there is a wide variability in follicular growth and ovulatory diameter between CO and CNO, which can affect the intervals of LH release, estradiol peak and ovulation. Yet, LH surge might be a good marker for timing ovulation in Zebu cows. [ABSTRACT FROM AUTHOR]

Purpose. To determine, by a plaque reduction assay, the in vitro efficacy of novel antiviral agents in the treatment of feline herpes virus 1 (FHV-1) keratitis in the domestic cat ( Felis felis ) . Materials and methods. A standard plaque reduction assay was performed using a laboratory strain of FHV-1 and embryo-derived feline kidney cells to determine the in vitro efficacy of the antiviral drugs penciclovir (PCV), bromovinyldeoxyuridine (BVdU), and ( S )-9-(3-hydroxy-2-phosphonylmethoxypropyl) adenine (HPMPA) and to compare these with the drugs acyclovir (ACV) and trifluorothymidine (TFT). Efficacy was assessed by determining the dose of drug at which 50% plaque reduction was noted (ED 50 ). Results. HPMPA was found to have greatest antiviral activity (ED 50 0.07 µg/ml). ACV was least active (ED 50 24 µg/ml), while TFT was active with an ED 50 of 5.7 µg/ml. PCV and BVdU had intermediate activity (ED 50 1.6 and 1.7 µg/ml, respectively). Conclusions. This study suggests that the efficacy of HPMPA, BVdU, and penciclovir in cats with herpesviral keratitis should be determined in vivo as their efficacy in vitro was substantially greater than that of acyclovir, already shown to have demonstrable but limited clinical antiviral activity. [ABSTRACT FROM AUTHOR]