Isolation of Mycoplasma salivarium from swine

Mycoplasma salivarium, a common human oropharyngeal mycoplasma, was isolated from nasal and pharyngeal secretions of 14 of 284 swine in a barrier-maintained, disease-free herd. M. salivarium was recovered from one boar 6 times over a 26-month period and one time only from 13 other swine. Human isolates of M. salivarium were compared with the swine isolates by DNA-DNA hybridization and SDS-PAGE of the cell proteins and the strains were shown to be closely related. One of eight of the swine from which M. salivarium was isolated had complement-fixing antibodies and another culture-positive animal had metabolic-inhibiting antibodies to M. salivarium. Overt disease was not associated with the organism. These results support previous findings that mycoplasmas closely related to M. salivarium may be isolated from the nasopharynges of swine and they further indicate that the organism can establish persistently in swine without evidence of overt disease.     

Clinical and subclinical colloid goitre in adult camels (Camelus dromedarius) at Kordofan region of Sudan

Colloid goitre was diagnosed in adult camels in the Kordofan region of the Sudan. The disease is characterized by gross enlargement of the thyroid, histopathological follicular changes, reproductive disorders, low concentrations of circulating thyroid hormones (T3, T4) and normocytic normochromic anaemia. The possible cause of the condition is discussed and iodine supplementation is recommended.     

Observations on the treatment of necrobacillosis in wallabies

Clinical experience of 73 cases of necrobacillosis in red-necked wallabies (Macropus rufogriseus) over a 6-year period is reviewed. Diagnostic methods and the medical and surgical treatment options are detailed. It is suggested that survival curves are necessary to assess the outcome of treatment.     

Equine metacarpophalangeal joint surface contact changes during walk, trot and gallop

Changes in the staining pattern for the metacarpophalangealjoint in the walking, trotting and galloping positions were studied. For this purpose, horse limbs from the third metacarpal bone distally were harvested and placed in the mid-stance position on a hydraulic press that applied the load required to obtain the palmar fetlock angles corresponding to the walking (218 degrees), trotting (226 degrees) and galloping positions (240 degrees), and a 1:1000 diluted aqueous dilution of methylene blue was injected into the fetlock joint.Based on the results, increasing the palmar fetlockangle in the anatomical specimen caused the contact zones of the proximal phalanx and the proximal sesamoidean bones with the third metacarpal bone joint surface to shift dorsally, thereby increasing the contact surface area between the involved bones.In the galloping position, the proximal phalanx wasfound to extend beyond the dorsal boundary of the third metacarpal bone joint surface and its basal portion to depart from the metacarpus in such a way that the distal sesamoidean ligaments forced the basilar zone of the proximal sesamoidean bones to separate.These phenomena may obviously assist in explaining the intricate biomechanics of the joint as well as its associated pathologies.     

Oxytocin synthesis and secretion from bovine corpora lutea exposed in vitro to cycloheximide and colchicine

Two experiments were conducted to study the effects of cycloheximide and colchicine on prostaglandin F₂ (PGF₂)-induced secretion and synthesis of oxytocin in bovine luteal tissue in vitro. Corpora lutea were collected from beef heifers on Day 8 of the estrous cycle. In Experiment 1, incorporation of [¹⁴C]-leucine into oxytocin synthesized and secreted by luteal slices after exposure to PGF₂, cycloheximide and cycloheximide plus PGF₂ was examined. In Experiment 2, synthesis and secretion of oxytocin were evaluated in luteal slices incubated with colchicine and PGF₂ alone and in combination. Cycloheximide inhibited incorporation of labeled leucine into luteal proteins by more than 90% and no labeled oxytocin was detected in the media or tissue. Prostaglandin F₂ induced significant secretion of oxytocin that was not inhibited by cycloheximide. Tissue levels of oxytocin after incubation with cycloheximide and/or PGF₂ did not differ and were similar to those of the incubated control. Colchicine alone did not suppress oxytocin secretion and did not alter the ability of PGF₂ to induce significant secretion of this nonapeptide. Tissue concentrations of oxytocin after incubation with colchicine and/or PGF₂ did not differ. These studies indicate that secretion and replenishment of luteal oxytocin in vitro is not contingent upon de novo protein synthesis. Inability of colchicine to suppress oxytocin secretion and synthesis may have been due to the short duration of exposure of luteal tissue to the drug.     

A method for the analysis of the δ18O of inorganic phosphate extracted from soils with HCl

The oxygen isotope composition of phosphate (δ¹⁸O‐PO₄) has successfully been used to study the biological cycling of phosphorus (P) in seawater and marine sediments. However, only a few studies have used this approach in soils. In order to analyse δ¹⁸O‐PO₄, phosphate must be extracted from the soil, purified and converted to silver phosphate (Ag₃PO₄). The published extraction methods, successfully applied to marine waters and sediments, lead to the precipitation of impure Ag₃PO₄when used with soils or organic‐rich samples. Here we present an improved purification protocol, designed for soils and other organic‐rich samples. After extraction with HCl, phosphate is purified with multiple mineral precipitations that do not require extreme pH adjustments of the solutions. We show that contaminant‐free Ag₃PO₄ can be produced from fertilizers and various soils with different chemical and physical characteristics. Our first isotopic results confirm that differences in P status and availability in soils are expressed in the δ¹⁸O‐PO₄ signal, indicating the potential of this isotopic tracer to understand P dynamics in soil systems.     

A Multivariate Hidden Markov Model for the Identification of Sea Regimes from Incomplete Skewed and Circular Time Series

The identification of sea regimes from environmental multivariate times series is complicated by the mixed linear?Ccircular support of the data, by the occurrence of missing values, by the skewness of some variables, and by the temporal autocorrelation of the measurements. We address these issues simultaneously by a hidden Markov approach, and segment the data into pairs of toroidal and skew-elliptical clusters by means of the inferred sequence of latent states. Toroidal clusters are defined by a class of bivariate von Mises densities, while skew-elliptical clusters are defined by mixed linear models with positive random effects. The core of the classification procedure is an EM algorithm accounting for missing measurements, unknown cluster membership, and random effects as different sources of incomplete information. Moreover, standard simulation routines allow for the efficient computation of bootstrap standard errors. The proposed procedure is illustrated for a multivariate marine time series, and identifies a number of wintertime regimes in the Adriatic Sea.     

海南省琼海市耕地养分状况及利用对策

海南省琼海市是全国无公害果菜生产示范市,在冬季瓜菜的生产中,起着举足轻重的作用,为了摸清琼海市耕地质量状况、影响耕地质量的因素以及耕地质量存在的问题,通过对已有成果资料的整理,以及在全市范围内采集土壤样本进行化验分析,通过化验数据了解琼海市土壤养分的现状,找出影响琼海市耕地质量的因素,以此为依据,对琼海市耕地提出四点利用对策,为琼海市耕地资源的合理利用、科学施肥以及无公害农产品生产等提供科学依据。     

Synchronizing rock clocks of Earth history

Calibration of the geological time scale is achieved by independent radioisotopic and astronomical dating, but these techniques yield discrepancies of approximately 1.0% or more, limiting our ability to reconstruct Earth history. To overcome this fundamental setback, we compared astronomical and 40Ar/39Ar ages of tephras in marine deposits in Morocco to calibrate the age of Fish Canyon sanidine, the most widely used standard in 40Ar/39Ar geochronology. This calibration results in a more precise older age of 28.201 +/- 0.046 million years ago (Ma) and reduces the 40Ar/39Ar method's absolute uncertainty from approximately 2.5 to 0.25%. In addition, this calibration provides tight constraints for the astronomical tuning of pre-Neogene successions, resulting in a mutually consistent age of approximately 65.95 Ma for the Cretaceous/Tertiary boundary.     

Multi-phase cross-correlation method for motion estimation of fertiliser granules during centrifugal spreading

Excessive fertiliser use has been a main contributor to the increasing environmental imbalance observed in the past 20 years. Better accuracy in spreading would limit excess fertiliser loss into the environment. Increased accuracy begins by understanding the fertiliser spreading process from the vane to the soil. Our work concentrates on the use of centrifugal spreaders, as these are most commonly used in Europe. Progress in imaging devices and image processing has resulted in the availability of new technologies to use when describing the behaviour of fertiliser granules during ejection from centrifugal spreaders. Fertiliser deposition on the soil can be predicted using a ballistic flight model, but this requires determination of the velocities and the directions of the granules when they leave the spinning disc. This paper presents improvements to the high speed imaging system that we had previously developed, i.e. enhancements to the illumination and the image processing. The illumination of the previous system, which used many separate flashes, did not give consistent illumination. We have improved it by using a stroboscope with power-LEDs, located at 1 m height around the digital camera and controlled by a Field-programmable gate array (FPGA) card. The image processing has been improved by development of a multi-phase method based on a cross-correlation algorithm. We have compared the cross-correlation method to the Markov Random Fields (MRF) method previously implemented. These tests, based on multi-exposure images, revealed that cross-correlation method gives more accurate results than the MRF technique, with guaranteed sub-pixel accuracy. Knowing that an error of one pixel can lead to a prediction error between 200 and 500 mm on the ground, the latter method gives an accuracy range between 0.1 and 0.4 pixels, whereas the MRFs technique is limited to 3 and 9 pixels for the vertical and horizontal components of the velocities, respectively. The sub-pixel accuracy of the new method was proven by applying it on simulated images with known displacements between the grains. By using a realistic spreading model, the simulated images are similar to those obtained with a high speed imaging system. This sub-pixel accuracy now makes it possible to decrease the resolution of the camera to that of a classical high-speed camera. These improvements have created an affordable and durable system appropriate for installation on a spreader. Farmers could use this system to both calibrate the spreader and verify the fertiliser distribution on the ground.