From landraces to modern cultivars: field observations on taro <Emphasis Type="Italic">Colocasia esculenta</Emphasis> (L.) Schott in sub-Saharan Africa

Until recently, taro Colocasia esculenta (L.) Schott, was considered a neglected food crop due to its low palatability and inferior value compared to other root crops such as cassava, potatoes and yams. Under the impulse of new studies on plant dispersal, and in light of the severe threats posed by pests to its conservation status, this crop has finally received more attention. However, there is still insufficient knowledge on specific cultivars and their culinary and medicinal uses, especially in Africa. We studied the agrodiversity of taro cultivars in Nigeria, Cameroon, the Democratic Republic of Congo, Kenya, and Tanzania. Here, we present ethnobotanical, morphological and linguistic data of 20 taro cultivars, as well as specific notes on abandoned landraces. These traditional varieties represent valuable genetic resources and can be instrumental in protecting taro from the genetic erosion caused by preference for yautia, and diseases such as the leaf blight. With this work, we call for renewed efforts to conserve this species and its landraces.     

Spatial distribution of Collembola in presence and absence of a predator

Many Collembola species are characterised by an aggregative behaviour, which is closely related to communication and co-ordination between individuals. In spite of a general heavy predation pressure, a large number of Collembola is found in soil suggesting that they have developed defence strategies against predators.

This study investigates changes in spatial structure of gregarious Collembola species in presence of a predator. It is analysed if the gregarious lifestyle of Collembola populations functions as a defence strategy against predation. In presence of a predator distances between individuals in the Collembola species Folsomia candida and Heteromurus tetrophthalmus became closer, reducing the risk of individuals to be captured by predators. On the contrary, Onychiurus sinensis specimens, which were never caught probably because of the extrusion of repelling fluids by means of their pseudocelli, moved away from each another. Besides being a successful chemical defence against predation, repelling fluid secretion may effectively repel conspecifics, thereby keeping individuals at greater distance.     

Bulk Atmospheric Deposition in the Southern Po Valley (Northern Italy)

A study on pH and chemical composition of precipitation was carried out in two Italian sites, one urban (site 1) and one rural (site 2), located approximately 30 km far from Bologna, during a 3-year period. No significative site variation was found. In both locations, bulk deposition pH ranged from slightly acid to slightly alkaline, despite the volume weighted mean concentration of acidic species, NO ₃ ^? and SO ₄ ^2? (67.4 and 118.4 μeq l^?1 in site 1 and 88.7 and 103.8 μeq l^?1 in site 2), that were similar to those of typical acidic rainfall region. This might be ascribed to the neutralization reaction of the Ca²⁺, attributed to the calcareous soil and the frequent dusty air mass intrusion from the Sahara. The pair correlation matrix and the analysis of the main components suggested also ammonium and other crustal elements as neutralization agents. The depositional rate of SO ₄ ^2? and NO ₃ ^? , chemical elements of agricultural interest, amounted to 38 and 28 and 32 and 35 kg ha^?1 for site 1 and site 2, respectively. These supplies of nutrient were not negligible and had to be considered on cultivated lands. NH ₄ ⁺ deposition rate on site 2 was 7 kg ha^?1, 23% over site 1, probably due to nitrogen fertilization in the fields around the monitoring station. In site 1, SO ₄ ^2? presented a seasonal trend, indicating that its principal source was the residential heating. Results emphasized that the entity of the bulk deposition acidification is linked not only to the ions local emission sources (fossil fuel combustions, heating, and fertilizers) but also to the surrounding territory and the prevalent wind that transports through kilometers air masses which may contain acidic and alkaline species.     

Detection of hepatitis E virus RNA in rats caught in pig farms from Northern Italy

Hepatitis E virus (HEV) strains belonging to the Orthohepevirus genus are divided into four species (A–D). HEV strains included in the Orthohepevirus A species infect humans and several other mammals. Among them, the HEV‐3 and HEV‐4 genotypes are zoonotic and infect both humans and animals, of which, pigs and wild boar are the main reservoirs. Viruses belonging to the Orthohepevirus C species (HEV‐C) have been considered to infect rats of different species and carnivores. Recently, two studies reported the detection of HEV‐C1 (rat HEV) RNA in immunocompromised and immunocompetent patients, suggesting a possible transmission of rat HEV to humans. The role of rats and mice as reservoir of HEV and the potential zoonotic transmission is still poorly known and deserves further investigation. To this purpose, in this study, the presence of HEV RNA was investigated in the intestinal contents and liver samples from 47 Black rats (Rattus rattus) and 21 House mice (Mus musculus) captured in four pig farms in Northern Italy. The presence of both Orthohepevirus A and C was investigated by the real‐rime RT‐PCR specific for HEV‐1 to HEV‐4 genotypes of Orthohepevirus A species and by a broad spectrum hemi‐nested RT‐PCR capable of detecting different HEV species including rat HEV. The intestinal content from two Black rats resulted positive for HEV‐C1 RNA and for HEV‐3 RNA, respectively. None of the House mice was HEV RNA positive. Sequence analyses confirmed the detection of HEV‐C1, genotype G1 and HEV‐3 subtype e. The viral strain HEV‐3e detected in the rat was identical to swine HEV strains detected in the same farm. Liver samples were negative for the detection of either rat HEV or HEV‐3.     

An integrated approach for cetacean knowledge and conservation in the central Mediterranean Sea using research and social media data sources

相似文献   

Tumour‐infiltrating lymphocytes in canine melanocytic tumours: An investigation on the prognostic role of CD3+ and CD20+ lymphocytic populations

The study of the immune response in several types of tumours has been rapidly increasing in recent years with the dual aim of understanding the interactions between neoplastic and immune cells and their importance in cancer pathogenesis and progression, as well as identifying targets for cancer immunotherapy. Despite being considered one of the most immunogenic tumour types, melanoma can progress in the presence of abundant lymphocytic infiltration, therefore suggesting that the immune response is not able to efficiently control tumour growth. The purpose of this study was to investigate whether the density, distribution and grade of tumour‐infiltrating lymphocytes (TILs) in 97 canine melanocytic tumours is associated with histologic indicators of malignancy and can be considered a prognostic factor in the dog. As a further step in the characterization of the immune response in melanocytic tumours, an immunohistochemical investigation was performed to evaluate the two main populations of TILs, T‐lymphocytes (CD3⁺) and B‐lymphocytes (CD20⁺). The results of our study show that TILs are present in a large proportion of canine melanocytic tumours, especially in oral melanomas, and that the infiltrate is usually mild. The quantity of CD20⁺ TILs was significantly associated with some histologic prognostic factors, such as the mitotic count, the cellular pleomorphism and the percentage of pigmented cells. Remarkably, a high infiltration of CD20⁺ TILs was associated with tumour‐related death, presence of metastasis/recurrence, shorter overall and disease‐free survival, increased hazard of death and of developing recurrence/metastasis, hence representing a potential new negative prognostic factor in canine melanocytic tumours.     

Production performance and plasma metabolite concentrations of broiler chickens fed low crude protein diets differing in Thr and Gly

The aim of the study was to test the interaction between Thr and Gly in low crude protein (CP) diets in 7 to 28 d broilers on production performance and plasma metabolites. A total of 2,040 broilers were allocated to 17 treatments. A positive control (PC) diet (20.5% CP) was formulated to be adequate in dietary Thr and Gly. A negative control (NC) diet (18.5% CP, deficient in Thr and Gly) was supplemented with crystalline l-Thr and Gly to obtain a 4 Thr × 4 Gly design. Dietary Thr was tested at an apparent faecal digestibility (AFD) Thr-to-Lys ratio, which was 55%, 58%, 61% or 64%, and dietary Gly was tested at an AFD (Gly + Ser)-to-Lys ratio, which was 135%, 142%, 149% or 156%. Plasma samples were collected at 28 d. The low CP diet, formulated at 64% Thr and 156% Gly, resulted in a higher body weight gain (BWG) (P < 0.01) and similar feed conversion ratio (FCR) as the high CP treatment (PC). FCR was improved (P < 0.001) by l-Thr supplementation. Quadratic response to dietary Thr was significant for feed intake (FI), BWG and FCR (P < 0.01). A near-significant interaction for Thr × Gly was observed for FI and BWG (P_linear = 0.091 and P = 0.074, respectively). Gly did not affect production performance. An interaction between Thr × Gly on plasma free AA level was observed (P < 0.05). Free AA concentration in plasma linearly decreased with increase in AFD Thr-to-Lys ratio, and increased with increase in AFD (Gly + Ser)-to-Lys ratio. Plasma uric acid concentration was higher in PC than in all of the other diets, and plasma triglyceride concentration was decreased by l-Thr supplementation, but not by Gly. In conclusion, Gly was not limiting for growth at low dietary CP level unless Thr was deficient, showing that adequate amounts of Thr in broiler diets can overcome marginal supply of Gly and Ser and allow reduction of dietary CP from 20.5% to 18.5% for broilers from 7 to 28 d of age.