In growing pigs, chlortetracycline induces a reversible green bone discoloration and a persistent increase of bone mineral density dependent of dosing regimen

We studied in growing pigs the effects of exposure to dietary chlortetracycline on bone mineral density (BMD) and bone color. Pigs were randomly allocated to a drug-free diet (n = 48) or a diet fortified with 800 ppm of chlortetracycline, starting either at 28- or 84-d of age, and for either a 28- or 56-d duration (n = 16 pigs/group). The lumbar vertebral discoloration and BMD of randomly chosen pigs were evaluated at 28-d intervals up to 168-d of age. The odds of bone discoloration increased with dosing duration and age at treatment onset, and decreased with the withdrawal time and age at treatment onset interaction (p ? 0.001). The measured trabecular BMD linearly increased with age and squared treatment duration (p ? 0.005). Therefore, TC-induced bone discoloration is reversible, and may be prevented with proper dosing regimen design. Moreover, TC induces a persistent increase on BMD that could be detected with quantitative computed tomography.     

Reoccurrence of a paranasal osteoma following surgical removal in a 6-month-old Warmblood filly

A 6-month-old Warmblood filly presented for evaluation of a left sided unilateral mucopurulent discharge of 5 weeks' duration. Upper airway endoscopy revealed a large, smooth mass in the region of the ethmoturbinates. Dorso-ventral and lateral radiographs of the head revealed a large osseous mass in the left paranasal area. A biopsy was performed under general anaesthesia and an osteoma was diagnosed. A computed tomography (CT) examination was performed to guide surgical removal. Surgery was performed under general anaesthesia and a large mass was removed ~15 × 9 cm. A CT examination 3 months following surgery revealed three small areas of mineralisation. It was difficult to differentiate if these were areas of regrowth or portions of the original mass that were not entirely removed. A CT examination 8 months later revealed one of the areas had increased moderately in size. A second surgery was performed standing to remove the growth. A final CT 8 months later revealed no further evidence of a bone growth. This report describes the successful removal of an osteoma regrowth following initial surgical removal and, to the best of the authors’ knowledge, is the first to describe the reoccurrence of an osteoma after surgical intervention. It also describes a successful rhinotomy in the standing equine patient. This case highlights the importance of serial follow-up imaging after surgical removal as osteoma regrowth occurred in this case.     

Computed tomographic and radiographic morphometric study of cardiac and coelomic dimensions in captive blue-fronted Amazon parrots (Amazona aestiva,Linnaeus, 1758) with varying body condition scores

This study aimed to assess radiographic and tomographic cardiac parameters, including width and length of the heart, and the ratio of heart width to coelom width of blue-fronted Amazon parrots (Amazona aestiva) with varying body condition scores. Thirty-five captive birds were included in the study and were allocated into one of three groups according to their respective body condition score: lean, ideal and obese. No differences were observed among the groups with regard to radiographic and tomographic measurements. Computed tomography enabled better identification of the structures of the cardiovascular system without interference from the overlying structures of the celomatic cavity observed in radiographic images. However, radiographic examinations should still be considered the standard screening method to identify cardiac alterations, such as increased or reduced organ dimensions. Standardizing the techniques and measurements performed in this study may serve as a basis for further research in the field.     

光信息技术在现代农业中的应用研究

以遥感科学与技术的定量化发展为切入点,系统的阐明了光信息与定量遥感技术在我国现代农业中应用现状与发展趋势。详细阐述了遥感科学与技术定量化发展的含义和应用意义,从农业资源调查及动态监测、农作物估产、灾害监测与评估,以及农业气象应用等几方面系统的回顾了遥感技术在我国农业中的应用历史和现状;最后分析了光信息及定量遥感技术与现代农业发展模式之间的关系,给出了促进我国农业信息化的发展趋势与方向。     

模拟冻融循环对黑土黏化层孔隙结构的影响

以东北典型黑土区耕地土壤为研究对象,采用室内模拟冻融以及CT(Computerized tomography)扫描相结合的方法,通过孔隙数目、平均面积、成圆率3个指标的量化与分析,研究了冻融循环对黏化层土壤孔隙特征的影响规律,以期为探明该区土壤侵蚀机理提供科学依据。研究结果表明,冻融循环不同程度地降低了原状土和填充土的孔隙数目和面积,均在循环3次时达到最低值,冻融循环对≥5 mm孔隙影响较为明显。相对原状土而言,前期含水量对黏化层填充土柱孔隙特征的影响较小。黏化层结构对模拟冻融循环的响应特征印证了季节性冻融循环对黑土区黏化层可蚀性的影响,进而诱发土壤侵蚀、促进沟蚀发展的可能。