Changing climate and changing vector-borne disease distribution: the example of Dirofilaria in Europe

Climatic changes, together with an increase in the movement of dogs across Europe, have caused an increase in the geographical range of Dirofilaria infections. The present paper is focuses on northeastern European countries, where survey data have shown an increase of Dirofilaria repens infections both in animals and humans. A growing degree day-based forecast model has been developed to predict the occurrence. The model is based on evidence that there is a threshold of 14 °C below which Dirofilaria development will not proceed in mosquitoes, there is a requirement of 130 growing degree-days (GDDs) for larvae to reach infectivity, and there is a maximum life expectancy of 30 days for a mosquito vector. The output of this model predicted that the summer temperatures (with peaks in August) are sufficient to facilitate extrinsic incubation of Dirofilaria even at latitudes of 56 °N and longitudes of 39 °E. Despite the fact that both Dirofilaria immitis and D. repens have the same temperature requirement for extrinsic incubation in mosquitoes, empirical data has shown that D. repens is the main cause of dirofilarial infections in both humans and animals. Clinical signs are absent in most canine infections with D. repens. Furthermore, diagnosis is problematic and in-clinic serological tests, such as those for D. immitis, do not exist. Therefore, most infections go undiagnosed, allowing the infection to spread undetected.     

Forest humus forms as potential indicators of soil carbon storage in Mediterranean environments

The aim of this work was to investigate the potential of forest humus forms as indicators of soil C storage. To this purpose, Mediterranean forest soils in Southern and Central Italy were examined. Sites differed for elevation, climate, parent material and vegetation conditions, while summer drought was the common ecological factor. A morpho-functional criterion, based on holorganic layers thickness and A horizon properties, was used to classify humus forms, which ranged from Dysmoder to Eumull. Such variability allowed understanding of factors influencing organic matter storage. The relations between carbon stock and humus form were investigated for the topsoil layer (0–20 cm), which was supposed to contain the soil C pools most sensitive to climate change. We found that humus forms can be grouped in statistically different populations, with respect to topsoil C stocks. The use of A horizon structure was the main diagnostic criterion and represented the most effective approach to humus classification in Mediterranean conditions. It appears that humus forms have a clear potential as indicators of organic carbon status in Mediterranean forest soils.     

Influence of nitrogen fertilization on yield and quality of canned fruits. I

The trial was carried out from 1970 to 1973 on Vivian canning clingstone peach variety grafted on seedling, planted in 1965 and trained as palmette spaced 5 × 4 metres.The aim was to control the influence of different rates of nitrogen on yield, growth and canned fruit characteristics including some chemical determinations (sugar, acidity).The treatments were: 120, 180 and 300 kg/ha of nitrogen.Yield, fruit size, trunk cross-section area, and pruning weight were recorded. In 1972 and 1973 a leaf analysis was also carried out.2 samples from each treatment were processed and canned.The U.S.D.A. quality standards, the flesh colour and the flavour were surveyed on the canned product.Treatment with 300 kg/ha of nitrogen do not give any benefit. The treatment 180 kg/ha of nitrogen seems to have a positive influence as compared to the minor N-supply (120 kg). An influence is evident in the growth of trees. Leaf analysis shows that the N level is practically the same in all treatments.On the basis of the experimental conditions, an annual supply of 120–180 N units/ha is sufficient to keep trees in the best productive conditions.

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Zusammenfassung Der Einfluß einer variierten Stickstoffdüngung auf Wachstum und Ertrag des Pfirsichs sowie auf das Verhalten der Frucht bei der Verwertung.Der Versuch wurde in einer 5jährigen Anlage in vier aufeinanderfolgenden Jahren (1970 bis 1973) durchgeführt. Als Sorte diente die für die Verwertung geeignete Vivian. Sie war auf Pfirsichsämling gepfropft, 1965 im Abstand von 5 × 4 m gepflanzt. Die Pfirsiche wurden hernach als Palmetten gezogen.Versuchsziel war, den Einfluß verschiedener Stickstoffgaben auf Wachstum und Ertrag sowie auf das Verhalten der Frucht bei der technologischen Verarbeitung zu ermitteln. Einige chemische Bestimmungen (Zucker, Säure) dienten zur Erfassung des Geschmacks.Die Stickstoffgaben, 120 kg, 180 kg und 300 kg Reinnährstoff/ha wurden, teils im Winter, teils im Frühjahr nach der Blüte, in 4 Gaben in Abständen von 20–25 Tagen verabfolgt.Stammdurchmesser, Gewicht des Schnittholzes sowie Ertragsmengen und Fruchtgröße wurden ermittelt. In den Jahren 1972 und 1973 sind auch Blattanalysen durchgeführt worden.Jeweils 2 Proben eines jeden Versuchsgliedes gingen in die Verwertung. Als Dosenkonserve wurden die Früchte auf Festigkeit des Fruchtfleisches, Farbe, pH-Wert, Gesamtsäure und USDA-Standards untersucht. Es konnte festgestellt werden, daß sehr hohe Gaben von 300 kg Rein-N/ha keinerlei Vorteile für Wachstum, Ertragshöhe, Fruchtgröße sowie für das Verhalten der Früchte bei der Konservierung brachten. Bei 180 kg Rein-N/ha war das Wachstum etwas stärker gegenüber 120 kg Rein-N. Blattanalysen erbrachten keine Unterschiede hinsichtlich des Ernährungszustandes der Palmetten. Dies erklärt auch die nur geringfügigen Unterschiede in den gesamten Ergebnissen.Unter den gegebenen Verhältnissen scheint es angebracht zu sein, die Stickstoffdüngung zwischen 120 und 180 kg Rein-N/ha zu bemessen, um die Pflanzen in einem optimalen Ernährungszustand zu halten.

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Résumé L'essai a porté sur une plantation de 5 ans, et s'est poursuivi durant quatre années consécutives (1970 à 1973). La variété utilisée était la Vivian. Elle avait été greffée en 1965 sur des pieds issus de graines; la plantation était faite à des intervalles de 5 × 4 m. Les arbres étaient conduits en palmettes.Le but était de suivre l'effet de diverses doses d'azote sur la croissance et le rendement, ainsi que sur le comportement des fruits lors de l'utilisation technologique. Quelques determinations chimiques (sucres, acides) ont servi à preciser le goût.Les doses d'azote (120, 180, 300 k. d'azote pur par hectare) ont été distribuées en hiver, au printemps, en 4 applications, à des intervalles de 20 à 25 jours. Le diamètre des troncs, la masse des branches taillées, la grosseur et la quantité de fruits ont été determinés. Les années 1972 et 1973 des analyses foliaires ont été pratiquées. Deux échantillons de chacun des pieds ont été envoyés à l'atelier de conserverie; la résistance mécanique de la chair du fruit, la couleur, le pH, l'acidité totale, les standards Américains ont été mesurés. Les très hautes doses (300 kg N/hectare) n'ont presenté aucun avantage, ni sur la croissance, ni sur le rendement, ni sur la taille des fruits, ni sur le comportement à la conserverie.180 kg N/hectare ont determiné une croissance un peu plus rapide que 120 kg/N. Les analyses foliaires n'ont pas montré un état physiologique meilleur des palmettes.Ce fait explique les différences très faibles mises en évidence dans cet essai.

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Paper read on the XIX. International Horticultural Congress in Warsaw, Poland, September, 10th to 18th, 1974.

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Note: The research has been financed by the Cassa per il Mezzogiorno.     

Aurantoside J: a new tetramic acid glycoside from Theonella swinhoei. Insights into the antifungal potential of aurantosides

The chemical investigation of an Indonesian specimen of Theonella swinhoei afforded four aurantosides, one of which, aurantoside J (5), is a new compound. The structure of this metabolite, exhibiting the unprecedented N-α-glycosidic linkage between the pentose and the tetramate units, has been determined through detailed spectroscopic analysis. The four obtained aurantosides have been tested against five fungal strains (four Candida and one Fusarium) responsible of invasive infections in immuno-compromised patients. The non-cytotoxic aurantoside I (4) was the single compound to show an excellent potency against all the tested strains, thus providing valuable insights about the antifungal potential of this class of compounds and the structure-activity relationships.     

Scaling issues in forest ecosystem management and how to address them with models

Scaling is widely recognized as a central issue in ecology. The associated cross-scale interactions and process transmutations make scaling (i.e. a change in spatial or temporal grain and extent) an important issue in understanding ecosystem structure and functioning. Moreover, current concepts of ecosystem stewardship, such as sustainability and resilience, are inherently scale-dependent. The importance of scale and scaling in the context of forest management is likely to further increase in the future because of the growing relevance of ecosystem services beyond timber production. As a result, a consideration of processes both below (e.g. leaf-level carbon uptake in the context of climate change mitigation) and above (e.g. managing for biodiversity conservation at the landscape scale) the traditional focus on the stand level is required in forest ecosystem management. Furthermore, climate change will affect a variety of ecosystem processes across scales, ranging from photosynthesis (tree organs) to disturbance regimes (landscape scale). Assessing potential climate change impacts on ecosystem services thus requires a multi-scale perspective. However, scaling issues have received comparatively little attention in the forest management community to date. Our objectives here are thus first, to synthesize scaling issues relevant to forest management and second, to elucidate ways of dealing with complex scaling problems by highlighting examples of how they can be addressed with ecosystem models. We have focused on three current management issues of particular importance in European forestry: (1) climate change mitigation through carbon sequestration, (2) multi-functional stand management for biodiversity and non-timber goods and services and (3) improving the resilience to natural disturbances. We conclude that taking into account the full spatiotemporal heterogeneity and dynamics of forest ecosystems in management decision-making is likely to make management more robust to increasing environmental and societal pressures. Models can aid this process through explicitly accounting for system dynamics and changing conditions, operationally addressing the complexity of cross-scale interactions and emerging properties. Our synthesis indicates that increased attention to scaling issues can help forest managers to integrate traditional management objectives with emerging concerns for ecosystem services and therefore deserves more attention in forestry.     

Diachronic analysis of individual-tree mortality in a Norway spruce stand in the eastern Italian Alps

? Understanding tree mortality processes across time requires long term studies. Spatiotemporal patterns of mortality in a 200 years-old mono-layered Norway spruce stand were evaluated to determine what factors affected individual-tree mortality.

? We performed an analysis on two surveys (1993 and 2005) in a 1-ha permanent plot in the Paneveggio forest (Eastern Italian Alps). Tree diameter and age distribution between surveys were compared. We examined spatial patterns of living and dead trees before 1993, in 1993 and in 2005 using univariate and bivariate Ripley’s K(d) function, and a kernel estimator of local crowding. A logistic model was used to assess the effects of diameter, age, recent growth and competitive pressure on tree mortality.

? Spatial pattern analysis indicated mortality was associated to tree neighbourhood (neighbour effect at 2–5 m). An increment of regularization of tree spatial pattern occurred due to density-dependent mortality. Logistic regression showed tree diameter and recent growth were determinant on mortality risk during the monitoring period.

? Even if the stand is relatively aged, mortality dynamics are those typical of stem exclusion stage. Mortality was related to competitive dynamics, and small suppressed trees with slow growth rate had higher probability to die.

     

Characterization of antimicrobial resistant Salmonella enterica serovars Enteritidis and Typhimurium isolates from animal and food in Southern Italy

In the last two decades, the emergence and spread of antimicrobial-resistant pathogens, among them Salmonella, has become a serious health hazard worldwide, and specifically the high incidence of multidrug resistance has been encountered widely in many European countries. This study examines the antimicrobial supsceptibility of Salmonella enterica strains Typhimurium and Enteritidis isolated in Campania and Calabria region (Southern Italy) from animal and food of animal origin. The relationship of antibiotic resistance phenotype and the presence of some resistance genes has been also investigated. As espected, our results showes that resistance to ampicillin, chloramphenicol, streptomycin, sulphonamides and tetracycline is common, although resistance to other antibiotics (i.e.:nalidixic acid) and other resistance patterns occur. The genetic resistant patterns have been partially described for this food-borne pathogen but efforts are needed to realize the complete characterization of antimicrobial resistance genes.     

Larval population structure of Engraulis encrasicolus in the Strait of Sicily as revealed by morphometric and genetic analysis

In order to investigate the larval population structure, specimens of Engraulis encrasicolus larvae from five different locations in the Strait of Sicily were analyzed by means of otolith readings, morphometric and genetic techniques. The distribution of age in day, identified by means of the otolith readings and associated with the oceanographic parameters, was useful to identify possible spawning areas and transport dynamics. The presence of more than one spawning area suggested the possibility that two or more sub‐populations may co‐exist in the study area. The morphometric characteristics were more adequate than genetic parameters to discriminate the different larval groups. The most relevant variables for the separation were the mouth length (ML) and the body diameter (BD). The population structure by means of genetic data reported the presence of two phylogroups co‐occurring among samples in each sampling locations specimens. The pattern of genetic divergence among anchovy larvae in the Strait of Sicily was congruent with previous studies conducted on adult populations present in other Mediterranean areas with different molecular markers. The habitat‐specific nature of the morphological variation and the lack of corresponding genetic variation among larvae from the different locations suggested that the observed differences in morphology could be linked to environmental parameters. The body form differences among different larvae samples could reflect the nutritional status of larvae. In fact, these differences were found among anchovy larvae collected in areas with different oxygen and fluorescence, which is an index of primary productivity and is linked to the availability of food for anchovy larvae.     

水泵水轮机甩负荷过程流动诱导噪声数值模拟

为研究水泵水轮机甩负荷过程压力脉动特性及其流动诱导噪声,该文基于网格壁面滑行技术和DES湍流模型,对水泵水轮机发电工况下导叶关闭过程进行连续性模拟,并将流场叶片表面压力脉动信号作为声场流动诱导噪声计算声源,通过对压力脉动特性和流动诱导噪声分析得到：导叶进出口处2个无叶区内压力脉动主频位置均在叶频为斯特劳哈尔数等于0.051与1处,导叶出口处频谱值是进口处10倍之上,说明动动干涉对流态的影响强于动静干涉;当尾水管内出现2个反向旋壁涡带时,压力脉动最强烈且其幅值最大。声场分析结果表明外场噪声的主频由压力脉动主频与壳体固有频率综合决定,声压分布具有"∞"形式的指向形态,且各阶叶频处声压分布呈现出明显的对称性,说明叶片噪声辐射具有明显的偶极子特性;在一阶、二阶叶频处,导叶关闭前一半阶段,流量对于外场噪声辐射能力的影响表现为大流量工况下最强,小流量工况下最弱,导叶关闭后一半阶段正好相反。