Near-infrared spectroscopy and X-ray fluorescence data fusion for olive leaf analysis and crop nutritional status determination.

Leaf analysis is a useful way of diagnosing the nutritional status of the plants and therefore fast methods of analysis are demanded to aid in fertilization management decisions. In this work, a strategy based on the combined use of near-infrared spectroscopy (NIR) and portable energy dispersive X-Ray Fluorescence (EDXRF) is proposed as a suitable cheap and rapid alternative to traditional wet analytical methodologies. The approach has the major benefit of minimal sample preparation since leaves need to be only dried and ground. The ability of both techniques individually and applying two strategies of data fusion for the prediction of the most important plant nutrients, namely N, P, K, Ca, Mg, Mn, Zn, and B was tested. Predictive models were constructed using Partial Least Squares (PLS) to correlate the spectra with the nutrient contents. Models of unequal prediction performance in terms of the ratio of predictive deviation (RPD) were obtained for the different parameters when considering both techniques separately. Low-level data fusion, which consists of a concatenation of the raw data from both techniques, showed little improvement and even decreased the predictive ability for some elements. Better results were obtained with mid-level data fusion, that is, merging data after a feature extraction step performed by means of Principal components analysis (PCA). The results show that a fair quantitative prediction is possible for Ca, K and Mn with RPDs ≥ 2 for external validation, whereas models for N and P allowed a semiquantitative estimation. Mg and B models were less satisfactory and can be used only for distinguish between low and high levels, while Zn content cannot be predicted. Finally, the potential of the fusion of FT-NIR and EDXRF spectroscopic data for the fast screening of olive crop nutritional status has been tested. Deficiencies in important elements like N and K has been successfully detected.

Do different characteristics of two emasculators make a difference in equine castration?

BACKGROUND: The Serra and Reimer emasculators are frequently used in equine orchiectomy. They differ in jaw profile and the mechanism by which they achieve haemostasis. OBJECTIVES: To investigate whether the haemostatic capacities of the Reimer and Serra emasculators in open and closed castration differ, to compare the haemostatic capacities of each emasculator in both open and closed castration, and to assess whether the tensile strength of the parietal tunic in closed castration differs according to whether a Reimer or Serra emasculator is used. STUDY DESIGN: Ex vivo randomised study. METHODS: Eighty equine cadaver testes were randomly assigned to two groups for, respectively, open and closed castration. Each group was divided into two subgroups for castration with a Serra or Reimer castrator, respectively. Testicular artery leaking pressure was measured by dye injection. In closed castration, the tensile strength of the parietal tunic was measured with a tensiometer. RESULTS: In open castration, the Reimer emasculator resisted significantly higher pressure (median: 706.1 mmHg; interquartile range [IQR]: 597.6-735.5 mmHg) than the Serra emasculator (median: 349.4 mmHg; IQR: 261.1-468.9 mmHg) (P<0.001), whereas no difference was found in closed castration (Serra emasculator, median: 382.5 mmHg [IQR: 294.2-568.2 mmHg]; Reimer emasculator, median: 419.2 mmHg [IQR: 294.2-616.0 mmHg]). The Reimer emasculator resisted significantly higher pressure in the open (median: 706.1 mmHg; IQR: 597.6-735.5 mmHg) compared with the closed (median: 419.2 mmHg; IQR: 294.2-616.0 mmHg) technique (P = 0.03). Parietal tunic tensile strength did not differ significantly by emasculator (mean ± s.d.: Serra, 12.65 ± 7.35; Reimer, 17.55 ± 11.76). MAIN LIMITATIONS: Limitations are inherent to the ex vivo study design. Post-surgery implications were investigated only in the short term and no account was taken of tissue inflammation and oedema, which may influence the integrity of the tissue. CONCLUSIONS: These results suggest it may be preferable to use a Reimer emasculator in open castration. In this ex vivo model of closed castration, no differences between the emasculators were observed.

Ex vivo comparison of the giant and transfixing knot in equine open and closed castration.

REASONS FOR PERFORMING STUDY: In equine castration, application of a ligature on the spermatic cord to prevent complications such as haemorrhage and evisceration has been reported with controversial results. Characteristics of commonly used knots have not been studied. OBJECTIVES: To compare the modified transfixing and giant knots and the emasculator in open and closed equine castration techniques. STUDY DESIGN: Ex vivo experiment. METHODS: A total of 144 testicles were randomly assigned to 2 groups for open or closed castration. Both groups were divided into 3 subgroups of 18 specimens each: emasculator only, emasculator plus giant knot and emasculator plus transfixing knot and the open castration group also contained 2 further subgroups of 18 testicles each: giant knot only and transfixing knot only. The length of suture material used was measured for each knot and the leaking pressure of the testicular artery measured using dye injection. In the closed castration group, parietal tunic tensile strength was measured with a tensiometer. RESULTS: Leaking pressure was higher in open compared with closed castration, with no significant difference among subgroups. In the closed castration group, minimum leaking pressure for the emasculator plus transfixing knot and emasculator only subgroups were close to standard physiological arterial pressures. The giant knot required less suture material than the transfixing knot. Parietal tunic tensile strength was higher when ligatures were applied. CONCLUSIONS: The giant and transfixing knot techniques have comparable haemostatic capability and parietal tunic tensile strength, but the giant knot requires less suture material. In open castration, using the emasculator alone may produce adequate haemostasis. In closed castration, using the giant knot in combination with the emasculator increases the bursting pressure and possibly reduces the incidence of haemorrhage. In closed castration, application of a ligature may reduce the risk of evisceration.