Effects of a weak DC electric field on root growth in Arundo donax (Poaceae)

Abstract

Electric fields can determine changes at the morphological and the physiological level in plants. Plants of Arundo donax L. (giant reed), obtained by set, grown on organic substrate were exposed to a DC electric field. A significant increase in growth rate was observed in the shoots and roots of treated plants. Treated roots also showed a modification in their morphology as compared to untreated ones. Our results point to a possibility of applying electric fields in plant propagation and reproduction.     

Unravelling landslide risk: soil susceptibility,agro‐forest systems and the socio‐economic profile of rural communities in Italy

Landslides are considered a form of physical soil degradation and are concentrated, especially in southern European countries, on inland and marginal rural areas. Low‐density, economically disadvantaged and poorly accessible areas are assumed to share a high landslide occurrence probability. However, an empirical verification of this assumption is still lacking for Mediterranean countries. This study investigates the spatial relation between a composite index of landslide risk and more than 100 indicators at the municipal level in Italy – a country with high landslide risk – exploring multiple territorial dimensions (population dynamics and settlements, job market and human capital, economic specialization and competitiveness, quality of life, agriculture and rural development, territory and environment). We combine nonparametric correlation, principal component analysis and hierarchical clustering, to profile municipalities according to their levels of landslide risk. The high landslide risk in certain areas of Italy is related to specific socio‐economic attributes (depopulation, ageing, tourism specialization, low density of economic activities, modest participation to the job market and crime intensity) and agro‐environmental features (low‐intensity cropping systems, natural landscapes and water resource availability).     

Use of seedling tubers from TPS in southern Italy

The TPS seedling tuber technique can be successfully adopted in developing as well as in developed countries as a standard agronomic system for potato production. Experimental work has been started in order to select the best parental lines and to evaluate the appropriate breeding schemes for the use of this technique in southern Italy. During 1989 48 true potato seed (TPS) families with different genetic backgrounds were tested for seedling tuber production and they produced a good yield. The seedling tuber families were tested for tuber production during 1990 by subdividing them in two size classes: 25mm-35mm and 35mm-45mm. The highest yield was attained by 4X x 2X families and the analysis of variance indicated significant differences with regard to tuber size and TPS families for both total and marketable tuber yield. This technique has significant potential for providing tubers for both the fall and winter crop in Italy.     

Preliminary investigation of a humoral and cell-mediated immunity ratio for diagnosis of paratuberculosis in beef cattle

One thousand three hundred and twenty-four adult beef cattle were tested for paratuberculosis using 2 antibody enzyme-linked immunosorbent assays (ELISA), an interferon-gamma (INF-γ) ELISA, and radiometric bacterial culture of feces from 5 populations. Two populations of cattle (n = 226) had data available to calculate a ratio of humoral to cell-mediated immunity based on results from one antibody test and the INF-γ ELISA. Latent class analysis was used to estimate accuracy of the 4 paratuberculosis assays within a Bayesian framework. Determination of test accuracy and paratuberculosis prevalence in the latent class analysis allowed for estimation of predictive value positive (PVP) functions. The estimated PVP functions were used to iteratively assign paratuberculosis status to sampled cattle. Accuracy of the immunity ratio, an antibody ELISA, and the INF-γ ELISA were determined for multiple cutoffs based on probabilistically assigned paratuberculosis status. Area under the receiver-operating characteristic (ROC) curves (95% probability interval) were estimated as 0.78 (0.66, 0.89), 0.81 (0.68, 0.92), and 0.59 (0.47, 0.71) for the immunity ratio, antibody ELISA, and INF-γ ELISA, respectively. The Youden index (sensitivity + specificity − 1) peaked at immunity ratios of 0.5 (J = 0.48) and 1.0 (J = 0.46). Sensitivity and specificity (95% probability interval) at an immunity ratio cutoff of 0.5 were 0.65 (0.44, 0.85) and 0.83 (0.78, 0.88), respectively. Sensitivity and specificity (95% probability interval) at the 1.0 cutoff were 0.55 (0.33, 0.77) and 0.91 (0.87, 0.95), respectively. An immunity ratio could be used to diagnosis paratuberculosis in beef cattle but requires further investigation.     

Diagnosis of Cauda Equina Abnormalities By Using Electromyography, Discography, and Epidurography in Dogs

Electromyography (EMG), L7-S1 discography and epidurography were investigated in 15 dogs with clinical signs of cauda equina dysfunction and in 7 control dogs without such clinical signs. Electromyography of paraspinal and pelvic limb muscles was done in 13 of 15 affected dogs. An L7-S1 discogram followed by an epidurogram was performed in all 22 dogs using 20% iopamidol. Results of discograms, epidurograms, and gross necropsy examinations were normal in six of seven control dogs. The one dog in which these studies were abnormal had a mild L7-S1 disc protrusion that did not result in nerve root compression at necropsy. Electromyographic analysis was 100% accurate in predicting the presence or absence of cauda equina disease. None of the results of discograms were falsely negative. Twelve of 15 discograms in clinically affected dogs indicated dorsal disc protrusion, but 2 of these protrusions were found to be noncompressive at surgery (13% error). Abnormal epidurograms occurred in 9 of 15 clinically affected dogs. There was one false positive and two false negatives (20% error). Electromyography was a sensitive screening technique for the presence of cauda equina disease. Discography may be more sensitive for detection of L7-S1 disc protrusion than epidurography. An abnormal radiographic contrast study of the cauda equina may only be useful when combined with an abnormal EMG.     

Evaluation of the inflammatory response to two intra-articular hyaluronic acid formulations in normal equine joints

Intra-articular (IA) hyaluronic acid (HA) is commonly used to treat equine arthritis. Inflammatory response or “joint flare” is a recognized potential side effect. However, the incidence and severity of inflammation following IA HA injection in horses is not well documented. This study compared the effects of two IA HA formulations of different molecular weight (MW) and a saline control on clinical signs and synovial fluid markers of inflammation in normal equine joints. Eight adult horses each had three healthy fetlock joints randomly assigned to treatment with either 1.4 mega Dalton HA, 0.8 mega Dalton HA or saline control once weekly for three weeks. Clinical evaluation and synovial fluid analysis were performed by blinded assessors. Outcomes of interest were lameness score, joint effusion score and synovial fluid white cell count and differential, total protein, viscosity and serum amyloid A. Joints injected with HA developed significant mild-to-moderate inflammatory responses often associated with lameness and joint effusion compared with saline control joints. The higher MW HA formulation elicited a significantly greater inflammatory response than the lower MW HA after the first injection. In HA injected joints, viscosity remained poor for the entire study. Both IA HA formulations in this study induced an inflammatory response in healthy equine joints. This may have implications for the use of HA in equine joints. The findings in this study are limited to the two HA formulations used. Further investigation of different HA formulations and the use of HA in normal and arthritic equine joints is warranted.     

Discrepancy between spindle anomalies and 2N pollen production insolanum interspecific hybrids

The cytological basis of 2n pollen production was studied in a diploidSolanum progeny coming from a cross between aS. tuberosum S. chacoense hybrid which does not produce2n pollen (T710) and a S.phurejar S. tuberosum hybrid (W5295.7) which does. Both parental clones showed anomalous orientation of spindles at Metaphase II of microsporogenesis, but only clone W5295.7 produced dyads. All plants of the progeny T710 × W5295.7 showed anomalous spindles at Metaphase II, but only 60% of them produced 2n pollen, thus evidencing a discrepancy between spindle anomalies and dyad/2n pollen production. This may suggest that both parallel and fused spindles are a necessary but insufficient condition for 2n pollen production, and that some other mechanisms expected to be more highly correlated with them may be involved in 2n pollen production in this population.