Interaction of 2,4,5-trichlorophenylsulphonylmethyl thiocyanate with fungal spores

Interaction of a new fungicidal compound, viz. 2, 4, 5-trichlorophenylsulphonylmethyl thiocyanate with spores of Fusarium culmorum has been investigated.The compound is readily taken up by spores and converted to the non-fungitoxic 2,4,5-trichlorophenylsuphinic acid, which is released into the ambient solution. Uptake of the thiocyanate can be markedly reduced by pretreatment of the spores with a thiol reagent like iodoacetic acid and slightly enhanced by pretreatment with a thiol, like dithiodglycol. Moreover, the thiocyanate reacts with thiols in vitro by forming the same sulphinic acid. Hence, it is concluded that the title compound is able to react with fungal cell thiols.However, addition of a thiol reagent does not affect the fungitoxicity of the thiocyanate. The absence of synergism suggests that the fungitoxicity of the thiocyanate is based at least partly on reaction with fungal cell thiols.The thiocyanate investigated resembles the fungicide captan with respect to both uptake pattern and failure to give synergism with a thiol reagent. These observations suggest that the fungicidal compounds have a similar mode of action, as far as reaction with fungal cell thiols is concerned.Samenvatting De interactie van een nieuwe fungicide verbinding nl. 2,4,5-trichloorfenylsulfonylmethyl thiocyanaat met sporen vanFusarium culmorum is onderzocht.De verbinding wordt goed door sporen opgenomen en omgezet in het niet fungitoxische 2,4,5-trichloorfenylsulfinezuur, dat aan de buitenoplossing wordt afgestaan. Opname van het thiocyanaat kan in aanzienlijke mate worden verlaagd door voorbehandeling van de sporen met een thiolreagens zoals joodazijnzuur, en enigszins worden verhoogd door voorbehandeling met een thiol zoals dithiodiglycol. Voorts reageert het thiocyanaat met thiolen in vitro onder vorming van hetzelfde sulfinzuur. De conclusie wordt getrokken, dat het thiocyanaat in staat is te reageren met thiolen van de schimmelcel.Toevoeging van een thiolreagens heeft echter geen invloed op de fungicide werking van het thiocyanaat. Het uitblijven van synergisme suggereert, dat de fungitoxiciteit van het thiocyanaat tenminste gedeeltelijk is gebaseerd op reacties met thiolen in de schimmelcel.Het onderzochte thiocyanaat gelijkt op het fungicide captan niet alleen in opnamepatroon maar ook wat betreft het uitblijven van synergisme met een thiolreagens. Deze waarnemingen suggereren dat de fungicide verbindingen hetzelfde werkingsmechanisme hebben, althans voorzover het reacties met thiolen van de schimmel betreft.     

A cohort study of preweaning piglet mortality and farrowing accommodation on 112 commercial pig farms in England

A cohort study was carried out on 112 breeding pig farms in England to investigate the impact of type of farrowing accommodation on preweaning mortality in piglets. Four types of farrowing accommodation were studied; farrowing crates, indoor loose pens, crate/loose systems (where the sow was restrained in a crate during birth and the first days of lactation before being moved to a loose pen) and outdoor farrowing in arcs in paddocks. Four estimates of preweaning mortality were collected: an oral estimate from the farmer before the visit, an estimate from the 6-month rolling average from computer records, records from 20 litters observed when the farm was visited and prospective records collected from 20 farrowings after the visit. These four estimates were significantly correlated. The prospective records also included a farmer reported date and cause of death. From the prospective data there were 25,031 piglets from 2143 litters from 112 farms, 6.5% of piglets were stillborn while live born preweaning mortality was 12%. Mixed effect discrete time survival, binomial and competing risk, models were used to investigate the association between preweaning mortality and farrowing accommodation, controlling for sow parity, litter size and number of piglets stillborn and fostered. There was a reduced risk of stillbirths in outdoor farrowing systems compared with crated systems. Farmers reported that crushing of healthy piglets was the most frequent cause of death accounting for 55% of live born preweaning mortality. There was no significant difference in mortality in live born piglets by farrowing system. There was a significantly higher risk of farmer reported crushing of healthy live born piglets in outdoor arcs compared with piglets reared with sows in farrowing crates and a significantly reduced risk of death from causes other than crushing in piglets reared outdoors or in crate/loose systems compared with piglets reared in crated systems. We conclude that, in the farms in this study, farrowing crates reduced the risk of preweaning live born mortality attributable to crushing but piglets in this system were at increased risk of death from other causes. Consequently crates had no significant effect on overall preweaning mortality percentage. In all four commercial production systems; outdoor, farrowing crates, crate/loose farrowing systems and indoor loose housed systems, there were similar levels of mortality.     

The theropod ancestry of birds: new evidence from the late cretaceous of madagascar

A partial skeleton of a primitive bird, Rahona ostromi, gen. et sp. nov., has been discovered from the Late Cretaceous of Madagascar. This specimen, although exhibiting avian features such as a reversed hallux and ulnar papillae, retains characteristics that indicate a theropod ancestry, including a pubic foot and hyposphene-hypantra vertebral articulations. Rahona has a robust, hyperextendible second digit on the hind foot that terminates in a sicklelike claw, a unique characteristic of the theropod groups Troodontidae and Dromaeosauridae. A phylogenetic analysis places Rahona with Archaeopteryx, making Rahona one of the most primitive birds yet discovered.     

Roles of bootstrap resampling,measure of central tendency,and method for calculating thermal units when developing phenology models for pest management

The successful development of phenology models from field studies depends on many factors, some of which are entirely under the control of pest managers. For example, one such factor is the choice of method for calculating thermal units. In this study, we have demonstrated that four methods for calculating thermal units provided for acceptable predictions of one phenological event of one insect species, while another method for calculating thermal units did not. The measure of central tendency (mean or median) that is used to estimate lower developmental temperatures and required thermal summations is another factor that pest managers can control when developing phenology models from field studies. Here, we show that predictions that were made when using phenology models based on median lower developmental temperatures and median required thermal summations were superior to predictions that were made when using phenology models based on mean lower developmental temperatures and mean required thermal summations. The use of bootstrap vs. non-bootstrap estimates of lower developmental temperatures and required thermal summations is yet another factor that pest managers can control when developing phenology models from field studies. In this study, we found that calculating and using bootstrap estimates of lower developmental temperatures and required thermal summations in phenology models did not improve the predictions of one phenological event for one insect species. The implications of these and other findings are discussed.     

Bacterial epididymitis in two stallions

Two stallions had unilateral bacterial epididymitis attributable to S zooepidemicus infection. Diagnosis was based on bacterial isolation, WBC in the semen, higher than normal blood fibrinogen concentration, and leukocytosis with regenerative left shift. One horse had high seminal pH. Ultrasonography of the involved epididymides revealed changes consistent with the appearance of abnormal accumulation of exudate in the tail of the epididymis. Treatment included unilateral orchiectomy and antibiotic administration. In stallion 1, the infection persisted despite treatment. Treatment result was not available for stallion 2.     

Long‐term Effects of Pyrethrin and Cyfluthrin,a Type II Synthetic Pyrethroid,Insecticide Applications on Bull Reproductive Parameters

The objectives of this study were to determine effects of cyfluthrin and pyrethrin spray products, used in combination with cyfluthrin topical and ear tag applications, on bull reproductive parameters over 18 weeks. Angus or Angus x Simmental bulls were randomly assigned to one of three treatment groups: (i) no exposure to pyrethrins/cyfluthrin (CONT; n = 10), (ii) cyfluthrin ear tag and topical applications (ET; n = 10), or (iii) cyfluthrin ear tag, topical, premise spray and pyrethrin fog spray applications (ET+S; n = 8). Bull body weight was measured every 3 week, and body condition score and scrotal circumference were recorded on weeks 0, 9 and 18. Semen and serum were collected every 3 weeks for sperm evaluation and testosterone measurement, respectively. There was a treatment × week interaction (p < 0.01) for sperm with primary defects; bulls in CONT group had a greater (p = 0.01) percentage of sperm with primary defects than bulls treated with insecticides at week 18. Overall and progressive sperm motility, normal sperm morphology, secondary sperm defects and serum testosterone concentrations changed (p < 0.01) over time in all bulls; however, treatment did not affect (p ≥ 0.13) any of these parameters. There were also no treatment effects (p ≥ 0.08) on bull body weight, body condition score or scrotal circumference. The use of pyrethrin‐ and cyfluthrin‐based insecticides, regardless of application, did not negatively affect reproductive parameters in beef bulls when administered over 18 weeks.     

Sensory Deprivation and Visual Speed: An Analysis

Two distinct but related pathways of protection against the lethal effects of ozone and nitrogen dioxide are shown by (i) simultaneous inhalation of compounds that furnish -SH or -SS-, or both, and (ii) by injection of thiourea derivatives several days prior to exposure to these oxidant gases. The mechanism of (i) is believed similar to that proposed for the action of radiation-protective compounds; that of (ii) involves the development of a tolerance initiated by the thiourea against the oxidants.