Effect of sampling density on regional soil organic carbon estimation for cultivated soils

An extensive knowledge of how sampling density affects soil organic C (SOC) estimation at regional scale is imperative to reduce uncertainty to a meaningful confidence level and aid in the development of sampling schemes that are both rational and economical. Using kriging prediction, this paper examined the effect of sampling density on regional SOC‐concentration estimations in cultivated topsoils at six scales in a 990 km² area of Yucheng County, a typical region in the N China Plain. Except the original data set (n = 394), five other sampling densities were recalculated using grids of 8 km × 8 km (n = 28), 8 km × 4 km (n = 44), 4 km × 4 km (n = 82), 4 km × 2 km (n = 142), and 2 km × 2 km (n = 257), respectively. Experimental SOC semivariances and kriging interpolations at six sampling density scales were calculated and modeled to estimate regional SOC variability. Accuracy of the effects of the five sampling densities on regional SOC estimations was assessed using the indices of mean error (ME) and root mean square error (RMSE) with 100 independent validation samples. By comparison with the kriged grid map derived from the 394 samples data set, the relative error (RE,%) was spatially calculated to highlight the spatial variability of prediction errors at five sampling‐density scales due to the intrinsic limitations of ME and RMSE in accuracy assessment. The results indicated that sampling density significantly affected the estimation of regional SOC concentration. Particularly when the sampling density was < 4 km × 4 km, the large spatial variation of SOC was concealed. Semivariance analysis indicated that different sampling density had significant effect on reasonable detection of the dominant factors which influenced SOC spatial variation. Greater sampling density could more exactly reveal regional SOC variation caused by human management. The prediction accuracy for regional SOC estimation increased with the increasing of sampling density. The critical areas with larger RE values should be intensified in the future sampling scheme, and the areas of lower RE values should be decreased relatively. A specific sampling scheme should be considered in accordance with the demand to the estimation accuracy of regional SOC stock at a certain confidence level. Our results will facilitate a better understanding of the effect of sampling density on regional SOC estimation for future sampling schemes by providing meaningful confidence levels.     

识别假劣、失效兽药的简易方法

介绍了识别假劣、失效兽药的简易方法,包括假劣兽药的外观识别和部分失效兽药的识别,可供畜牧养殖者参考.     

Cardiopulmonary effects of buprenorphine in horses

OBJECTIVE: To investigate the effects of buprenorphine on cardiopulmonary variables and on abdominal auscultation scores in horses. ANIMALS: 6 healthy adult horses. PROCEDURES: Horses were restrained in stocks and allocated to 2 treatments in a randomized crossover design, with 1-week intervals between each treatment. Saline (0.9% NaCl) solution was administered IV as a control, whereas buprenorphine (10 mug/kg, IV) was administered to the experimental group. Cardiopulmonary data were collected for 120 minutes after buprenorphine or saline solution administration. Abdominal auscultation scores were monitored for 2 and 12 hours after drug administration in the control and experimental groups, respectively. RESULTS: Following control treatment, horses remained calm while restrained in the stocks and no significant changes in cardiopulmonary variables were observed throughout the study. Buprenorphine administration caused excitatory phenomena (restlessness and head shaking). Heart rate, cardiac index, and arterial blood pressure were significantly increased after buprenorphine administration until the end of the observational period (120 minutes). Minimal changes were found in arterial blood gas tensions. Abdominal auscultation scores decreased significantly from baseline for 4 hours after buprenorphine administration. CONCLUSIONS AND CLINICAL RELEVANCE: Buprenorphine induced excitement and hemodynamic stimulation with minimal changes in arterial blood gas tensions. These effects may impact the clinical use of buprenorphine in horses. Further studies are indicated to investigate the effects of buprenorphine on gastrointestinal motility and fecal output.     

The Role of Hypothyroidism in the Etiology and Progression of Dilated Cardiomyopathy in Doberman Pinschers

Background

Hypothyroidism and dilated cardiomyopathy (DCM) are both common diseases in Doberman Pinschers. A possible influence of hypothyroidism on the etiology and progression of DCM is controversial.

Objectives

Evaluation of the role of hypothyroidism in etiology and progression of DCM.

Animals

A total of 175 Doberman Pinschers.

Methods

In this longitudinal prospective study, echocardiography and 24‐hour ambulatory ECG recordings were performed in all dogs as screening tests for DCM. Total thyroxine (TT₄) and thyroid ultrasonography served as initial screening tests for hypothyroidism and low TT₄ values were followed up by a thyroid stimulating hormone (TSH) test or free total thyroxine (fT ₄)/cTSH measurements. Additionally, a follow‐up study of dogs affected by both DCM and hypothyroidism under optimal treatment for hypothyroidism was conducted.

Results

A total of 107 dogs were healthy, 45 dogs had DCM, 11 hypothyroidism, and 12 dogs had both DCM and hypothyroidism. TT ₄ values as well as the thyroid volumes were equivalent in the healthy dogs and in those with DCM. Neither ventricular premature complexes nor echocardiographic parameters differed between healthy and hypothyroid dogs. Dogs with DCM had a 2.26‐fold (CI_0.95 = 1.1–4.8) higher risk of also being affected by hypothyroidism. Despite optimal thyroid treatment of dogs with hypothyroidism and DCM, there was a progression of the heart disease.

Conclusions and Clinical Importance

This study did not confirm a role of hypothyroidism in the etiology or progression of DCM. Treatment of hypothyroidism did not improve the clinical outcome.     

Illuminating the evolutionary history of chlamydiae

Chlamydiae are the major cause of preventable blindness and sexually transmitted disease. Genome analysis of a chlamydia-related symbiont of free-living amoebae revealed that it is twice as large as any of the pathogenic chlamydiae and had few signs of recent lateral gene acquisition. We showed that about 700 million years ago the last common ancestor of pathogenic and symbiotic chlamydiae was already adapted to intracellular survival in early eukaryotes and contained many virulence factors found in modern pathogenic chlamydiae, including a type III secretion system. Ancient chlamydiae appear to be the originators of mechanisms for the exploitation of eukaryotic cells.     

Magic applied to roof experiments (Risdalsheia,N; Gårdsjön,S; Klosterhede,DK) to evaluate the rate of reversibility of acidification following experimentally reduced acid deposition

Soil and stream water responses to clean rain treatments at three roof covered forest ecosystems in Norway, Sweden and Denmark were modelled by the MAGIC model. The model outputs were compared with measured responses. Over the wide span in site conditions among the three sites MAGIC successfully reproduced the observed effects in the clean rain treatments. Seasalt influence caused single year discrepancies but the long term trends were well reproduced. In particular the significant decreases in SO₄ output were well reproduced. A simultaneous change in base cation leaching was observed, which in the long run will be the basis for the recovery of these acidified systems. The rate of recovery at the 3 studied sites was very slow.     

The exman project—Biogeochemical fluxes in plantation forests on acid soils

As a basis for experimentation, inputs and outputs of biogeochemicals were observed in coniferous stands in Denmark, the Netherlands, Germany and Ireland. The range of deposition observed is characteristic of populated regions of northwest Europe, from only moderately polluted Atlantic areas through decreasing marine influence and increasing deposition of anthropogenic nitrogen and sulphur. In intensive agricultural regions, ammonium inputs are high enough to cause nitrogen saturation of ecosystems, and nitrificationacidification is a major soil process. Co-deposition of ammonia and sulphur dioxide may be significantly increasing loads of N and S in forests in the region. Input-outputs are balanced for seasalts in the maritime sites, and sulphur outputs from the rooting zone also reflect the inputs to a large degree on these sites. Mobilisation of cations, notably aluminium, apparently occurs as a result of acidity generated by nitrogen transformations.     

Surgical results and fertility following correction of vesicovaginal reflux in mares

Objective To evaluate the surgical results and fertility of mares bred at various intervals relative to surgical management of urovagina. Design Sixty-one mares underwent surgery to correct vesicovaginal reflux. Surgery was performed at varying times relative to breeding and postoperative fertility was evaluated. Results Five mares were lost to follow-up and a further four were electively not bred. Of the remaining 52 mares, seasonal pregnancy and live foaling rates were 67% (35/52) and 54% (26/48), respectively. When mares were bred in the same cycle as the surgery, the first cycle following surgery, the second cycle following surgery or the following breeding season after surgery the seasonal pregnancy rates were 89% (8/9), 63% (10/16), 67% (2/3) and 63% (15/24), respectively. After censoring four mares that died of natural causes pre-foaling, the foaling rates were 88% (7/8), 50% (7/14), 0% (0/3), 52% (12/23), respectively. All mares bred in the same cycle as surgery or in the next cycle were bred once only that season, so the pregnancy rate per cycle of 72% (18/25) was identical to the seasonal pregnancy rate. Conclusions Good fertility (comparable to a normal population of mares) was achieved following surgery and the results suggest that delaying breeding until the following breeding season is not necessary. In addition, breeding in the same cycle as surgical repair is a previously unreported technique that should be considered to maintain a yearly foaling interval.     

Distal luxation of the patella in a horse

A 19-year-old Thoroughbred gelding presented with sudden onset, non-weight bearing lameness in the right hindlimb. Radiography confirmed distal luxation of the patella, which was replaced into its normal anatomical location under general anaesthesia. There were no pathological sequelae noted on follow-up examination 9 months after the initial injury. To our knowledge, this is a rare manifestation of patellar luxation, only reported once previously in the equine literature.