Cheek teeth (CT) diastemata are now recognised as a clinically significant equine disorder, but their prevalence in the general equine population is unknown. There is also limited information on the signalment of affected horses; the more commonly affected Triadan sites; and the shape and clinical characteristics of CT diastemata. During the 12-month study period (2008 to 2009), standardised records were obtained during routine dental examinations performed by five veterinarians in a first-opinion equine practice. Cheek teeth diastemata were identified in 49.9 per cent of all horses (n=471) of mean age 11 years (range one to 30 years), with 83.5 per cent of all diastemata affecting mandibular CT and 16.5 per cent affecting maxillary CT. The mean number of diastemata per case was 1.7 (range one to 20) and the mandibular 07 to 08 position was most commonly affected. Valve diastemata were more common (72.1 per cent prevalence) than open diastemata (27.9 per cent). Food trapping was present in 91.4 per cent of diastemata, with gingivitis and periodontal pockets adjacent to 34.2 per cent and 43.7 per cent, respectively. Halitosis was present in 45.5 per cent of affected horses. There was an age-related increase in both the prevalence of diastemata, and in the numbers of diastemata per affected horse, and horses over 15 years old had a significantly increased proportion of open diastemata.

In January 2016 the United Kingdom's southern European Monitoring and Evaluation Programme (EMEP) level-2 air pollution monitoring 'supersite' was relocated from Harwell, Oxfordshire to Chilbolton Observatory, Hampshire. As no co-location study was undertaken, this work retrospectively investigates whether the supersite relocation has led to discontinuities in the time series of concentrations of commonly studied gaseous pollutants (NO x , NH 3 , SO 2 and O 3 ) and particulate matter (PM 2.5 and PM 10 ). Two years of measurements pre-and post-relocation (2014-15 and 2016-17 respectively) were analysed in conjunction with meteorological variables and local emission data. The deweather package was applied to the concatenated time series to minimise the influence of meteorology. Similar average concentrations of PM 2.5 , PM 10 , SO 2 and O 3 were observed, but there were substantial differences in that of NO x and NH 3 (increase by factors of ∼1.6 and ∼3, respectively). The considerably higher NH 3 concentrations at Chilbolton are attributed to the close proximity of mixed farmland, in particular to a strong south-westerly source contributing to ∼50% of the annual average. NO x and PM concentrations in easterly winds arriving at Chilbolton are ∼2.7 and ∼1.5 times larger than at Harwell, from sources including the M3 motorway and Greater London. Westerly concentrations of NO x remain similar, therefore despite a higher frequency of westerly wind, annual mean concentrations are larger. Lower concentrations of PM arriving from the west result in similar annual averages. The secondary inorganic and black carbon components of PM were broadly similar between the sites. The differences in average NO x and NH 3 at Chilbolton must be taken into account when considering long-term regional trends based on the southern UK supersite data.

The objective of the current study is to evaluate the impact of induced starvation on horn fly susceptibility to permethrin and general reproduction using filter paper and manure bioassays, respectively. Incorporating push-pull systems for horn fly control has recently gained much attention for use in managing this pest. However, the consequences of temporary starvation associated with the relocation of horn flies from one host to another have yet to be fully explored. Susceptible (SS) and permethrin resistant (PR) horn flies were randomly allocated to one of four treatment groups: 1- blood fed, 2- partially starved (4hr), 3- moderately starved (8hr), and 4- severely starved (12hr). Permethrin resistant flies were 1,227 times more (P < 0.05) tolerant to permethrin in comparison to SS flies. Furthermore, SS blood fed flies were 1.18, 1.89, and 3.12 times more tolerant to permethrin than SS flies starved for 4, 8, and 12 hours, respectively. Egg hatching rates decreased (P < 0.04) for 8hr and 12hr starved flies in comparison to blood fed flies. Larval development, as measured through manure bioassays was lower (P = 0.02) in severely starved flies in comparison to blood fed flies. Pupae sizes were unaffected (P = 0.58) by starvation and fly strain. These results indicate that susceptibility to permethrin increases as time without a blood meal increases and furthermore, offspring success is reduced specifically through egg viability. Findings from this work will help further expand current integrated pest management options for animal producers by increasing our understanding and implementation of push-pull strategies in animal production systems.

Accurate photolysis rate constants are essential for simulation of local air quality but their values can vary substantially with changes in local meteorological and surface conditions. This study demonstrates the use of local radiometer measurements for capturing via hourly measurement-driven adjustment factors (MDAF) the temporal resolution needed to adjust clear-sky or cloud-free model estimates of j(NO2). Measurements simultaneously at two sites in the UK (Auchencorth Moss and Manchester) showed that TUV (v5.3) model estimates of j(NO2)↓ in cloud-free conditions (used as an example of modelled j-values) were, on average, approximately 45% larger than measured j(NO2)↓, which would lead to substantial model bias in the absence of local adjustment. At Auchencorth Moss, MDAF values based on 4π and 2π radiometer inlets generally agreed very well with each other (<6% average difference). However, under conditions of particularly high surface albedo (such as snow cover), increased upwelling local diffuse radiation yielded an MDAF derived using total radiation (sum of ↓ and ↑ components) ~40% larger than the MDAF derived using only ↓ radiation. The study has demonstrated: (1) the magnitude of potential impact of local conditions—principally cloud cover, but also changes in surface albedo—on assumed j-values; (2) that whilst annual mean MDAF values are similar at Auchencorth Moss and Manchester, there is no contemporaneous correlation between them at hourly resolution; hence MDAF values derived at one site cannot readily be applied at another site. These data illustrate the need to routinely deploy long-term radiometer measurements alongside compositional measurements to support atmospheric chemistry modelling.

Abstract. Production of hydroxyl (OH) radicals is frequently dominated by the photolysis of tropospheric ozone (O3). However, photolysis of nocturnal radical reservoirs, such as nitrous acid (HONO) and nitryl chloride (ClNO2), also produces radicals (OH and Cl atoms) that contribute to the oxidising capacity of the local atmosphere, and initiate many radical-chain reactions that lead to the formation of harmful secondary pollutants. Photolysis of nitric acid (HNO3) is also a minor radical production mechanism. In this paper, locally representative photolysis rate constants (j-values) for these molecules are shown to be critical for quantifying and understanding the rate of radical production in a local atmosphere. The first long-term 4-π filter radiometer dataset in the UK (21 November 2018–20 November 2019) available for direct atmospheric model validation is reported. Measurements were made at Auchencorth Moss, a Scottish rural background site, and j(NO2) is used to generate a measurement-driven adjustment factor (MDAF) for calculated j-values that accounts for local changes in meteorological variables without significantly increasing computational cost. Modelled clear-sky j-values and actinic flux for Auchencorth Moss were generated using the Tropospheric Ultraviolet and Visible radiation model (TUV; v.5.3.1). Applying the MDAF metric resulted in the calculated photolytic production rate of OH radicals, from all sources considered, being ~40 % lower over the year. Photolysis of HONO resulted in an increased rate of OH production compared to that from O3 in low-light conditions, such as sunrise and sunset (Solar Zenith Angle > 80°). Hydroxyl radical production from HONO photolysis exceeded that from O3 consistently throughout the day during the winter and autumn (by a factor of 5 and 2.1, respectively). Radical production rates from HONO and ClNO2 reached maximum values during the early morning hours of summer (06:00–09:00 UTC), with OH produced at a rate of 1.06 × 106 OH radicals cm−3 s−1, and Cl radicals at 3.20 × 104 Cl radicals cm−3 s−1, with the MDAF metric applied. This first application of the MDAF j-values demonstrates an efficient measurement and computational approach to improve modelling of the local atmospheric photochemistry that drives NO2, O3 and PM pollution levels. The incorporation of local radiation measurements in measurement networks, and the consequent greater spatial resolution of locally-relevant photolysis coefficients in model photolysis parameterisations, will improve the accuracy of assessment of air pollution and policy-intervention impacts.

Twelve Angus × Hereford crossbred heifers were used in a completely randomized design to evaluate the effects of monensin and diflubenzuron feed additives on horn fly (Haematobia irritans) (L.) and house fly (Musca domestica) (L.) immature development. Heifers were randomly assigned to one of four treatment groups; 1) monensin fed at label rate, 2) diflubenzuron fed at label rate, 3) monensin and diflubenzuron fed at label rates together, and 4) nonsupplemented control. All treatments were administered from SD 0 to 28, followed by a 16-d wash-out period for a total study duration of 45 d and assayed to assess adult fly emergence, as well as fecal pH and fecal bacterial and total protein. A treatment × day interaction (P &lt; 0.01) was observed for adult fly emergence. Fly emergence was not affected (P ≥ 0.05) by monensin, but was reduced during the 28 d treatment period when diflubenzuron was present (P = 0.01). Fecal pH, fecal bacterial protein, and total protein were not affected by any of the treatments (P ≥ 0.13). It is concluded that diflubenzuron is effective against both horn and house fly development regardless of the presence of monensin.

Photolysis rate constants (j-values) play a crucial role in atmospheric chemistry modelling, but capturing the variability in local conditions needed for their accurate simulation is computationally challenging. One approach is...

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