574 research outputs found
Organic versus mineral fertilization: Assessing of yield and quality of durum wheat in marginal lands
Durum wheat is often cultivated in marginal areas with great management difficulties. Organic fertilization is a sustainable agricultural practice that allows preserving the environment, but its limit can be the reduction of yield and quality of crops, also in cereals. The aim of research was to evaluate the effects of the organic fertilization on yield and quality of Simeto, a variety of durum wheat, cultivated for two years in three different sites of the internal hill of Campania Region (San Giorgio la Molara, SGM; Ariano Irpino, AI; Sant’Angelo dei Lombardi, SAL). SGM was a sandy-clay-loam soil, with high fertility, while AI and SAL were clay soil. The organic fertilization (ORG), based on roasted leather, was compared to mineral fertilization (MIN) and the not fertilized treatment (N0). In SGM, crop growth rate (CGR) and leaf area index (LAI) were significantly higher than AI and SAL until the flowering (about 2-and 4-fold more, respectively). MIN and ORG significantly boosted CGR compared to N0, while for LAI, ORG was never different from N0. The two-years value of yield was 3.0 t ha–1; in SGM, it reached 4.2 t ha–1, and it was 54.6% more than the mean value of AI and SAL, while N0 was not different from MIN of AI and SAL. ORG yield was lower and not different from NO in AI, where the lowest values of 1000 kernels weight, and hectolitre weight were also recorded. MIN and ORG increased the number of spikes per square meter: 27.0%, and 12.8% over N0, respectively, but ORG showed an 11.2% decrease compared to MIN. The 1000 kernels weight reached the highest values in SAL, without differences between N0, MIN, and ORG. The values of protein and gluten percentage were highest in AI and SGM (about 13.5%, and 11.7%, respectively), but without differences between ORG and MIN in the 3 sites for protein percentage. The worst value of the vitreousness was recorded in SAL (52.3%), six-fold more than that of AI (8.2%), probably due to the high rainfall. NUE reached the highest value in SGM in the first year, when it was significantly different from AI and SAL (0.036 vs 0.030 t kg–1). Overall, the effect of nitrogen fertilization type results site-specific; indeed, organic fertilization had the same performance of mineral in the site with better soil (low clay content, high nitrogen, and organic matter content) and climate conditions
Agronomic and environmental benefits of ‘re-using’ a biodegradable mulching film for two consecutive lettuce cycles
Biodegradable films are a valuable and sustainable alternative to plastic films for mulching soils since they avoid the environmental and economic problems related to plastic removal and dis posal. Nevertheless, the fast degradation of such materials could make them unsuitable for mid-to long-term use. In a field experiment, the agronomic performance of a biodegradable mulching film (MB) was compared to that of conventional low-density polyethylene (LDPE) film for two consecutive lettuce cycles (winter and spring). In the conditions of this trial, MB showed good resistance to atmospheric agents, with a reduction of its integrity and mechanical properties only after six months. The effects on soil temperature and lettuce yield did not differ from those obtained with LDPE films. The effect on harvest timing was the same as that with LDPE in the spring cycle, while in the winter cycle, the harvest was delayed by about five days compared to LDPE. Mulching films reduced nitrate accumulation in leaves mainly during the winter cycle. However, the effect needs to be further explored with experiments in different pedoclimatic conditions that consider the effects of mulching on nitrification and nitrate-reductase activity that could be affected by changes in soil temperature and moisture
Association between a genetic variant of type-1 cannabinoid receptor and inflammatory neurodegeneration in multiple sclerosis
Genetic ablation of type-1 cannabinoid receptors (CB1Rs) exacerbates the neurodegenerative damage of experimental autoimmune encephalomyelitis, the rodent model of multiple sclerosis (MS). To address the role on CB1Rs in the pathophysiology of human MS, we first investigated the impact of AAT trinucleotide short tandem repeat polymorphism of CNR1 gene on CB1R cell expression, and secondly on the inflammatory neurodegeneration process responsible for irreversible disability in MS patients. We found that MS patients with long AAT repeats within the CNR1 gene (≥12 in both alleles) had more pronounced neuronal degeneration in response to inflammatory white matter damage both in the optic nerve and in the cortex. Optical Coherence Tomography (OCT), in fact, showed more severe alterations of the retinal nerve fiber layer (RNFL) thickness and of the macular volume (MV) after an episode of optic neuritis in MS patients carrying the long AAT genotype of CNR1. MS patients with long AAT repeats also had magnetic resonance imaging (MRI) evidence of increased gray matter damage in response to inflammatory lesions of the white matter, especially in areas with a major role in cognition. In parallel, visual abilities evaluated at the low contrast acuity test, and cognitive performances were negatively influenced by the long AAT CNR1 genotype in our sample of MS patients. Our results demonstrate the biological relevance of the (AAT)n CNR1 repeats in the inflammatory neurodegenerative damage of MS
Comparative assessment of autochthonous bacterial and fungal communities and microbial biomarkers of polluted agricultural soils of the Terra dei Fuochi
Organic and inorganic xenobiotic compounds can affect the potential ecological function of the soil,
altering its biodiversity. Therefore, the response of microbial communities to environmental pollution
is a critical issue in soil ecology. Here, a high-throughput sequencing approach was used to investigate
the indigenous bacterial and fungal community structure as well as the impact of pollutants on their
diversity and richness in contaminated and noncontaminated soils of a National Interest Priority Site of
Campania Region (Italy) called “Terra dei Fuochi”. The microbial populations shifted in the polluted soils
via their mechanism of adaptation to contamination, establishing a new balance among prokaryotic
and eukaryotic populations. Statistical analyses showed that the indigenous microbial communities
were most strongly affected by contamination rather than by site of origin. Overabundant taxa and
Actinobacteria were identified as sensitive biomarkers for assessing soil pollution and could provide
general information on the health of the environment. This study has important implications for
microbial ecology in contaminated environments, increasing our knowledge of the capacity of natural
ecosystems to develop microbiota adapted to polluted soil in sites with high agricultural potential and
providing a possible approach for modeling pollution indicators for bioremediation purposes
Study of the chemical interaction between a high-viscosity glass ionomer cement and dentin
Objective: To investigate the chemical interactions between a high-viscosity glass ionomer cement (GIC) (KetacTM Molar Easymix, 3M ESPE, Seefeld, Bavaria, Germany) and human dentin. It was also analyzed the dynamics of GIC setting mechanism based on the time intervals required for the GIC and the GIC mixed with dentin to achieve stability. Material and Methods: Each constituent of GIC – powder (P) and liquid (L) – and powdered dentin (D), as well as the associations P+L, D+L, and P+L+D in the concentrations of 29%, 50%, 65%, 78%, 82%, and 92% of GIC were analyzed with Fourier transform infrared (FTIR) and Raman spectroscopy. Results: New optical absorption bands and/or Raman bands, which were not present in P, L, or D, were observed in the associations. The concentrations of 29% and 50% of GIC showed higher interaction, revealing that the amount of dentin influences the formation of new optical absorption or scattering bands. FTIR bands showed that the setting time to achieve bond stability was longer for the high-viscosity GIC (38±7 min) than for the sample with 29% of GIC (28±4 min). Conclusions: The analysis revealed the formation of new compounds or molecular rearrangements resulting from the chemical interactions between GIC and dentin. Moreover, this study provides an effective method to evaluate the dynamics of the setting mechanism of GICs
PRODUTIVIDADE E CARACTERÍSTICAS REPRODUTIVAS DO ARUANÃ, Osteoglossum bicirrhosum (OSTEOGLOSSIFORMES: OSTEOGLOSSIDAE), NO LAGO GRANDE, BACIA DO RIO PUTUMAYO, PERU
Due to the importance of ornamental fishing of silver arowana, as well as, Lago Grande lake as one of the main areas for capturing baby arowanas in Peru, the present study aimed to evaluate the productivity and the biological-reproductive characteristics of the species in the lake, which is located in the lower basin of the Putumayo River and represents an area preferred by fishermen because the important populations of silver arowana inhabiting it. Analysis of population density, biometrics, sexual maturity, spawning, fecundity, sex ratio, water level of the lake and production of baby arowana were made. The study was developed between March and July of 2012 and to implement the activities of the study was important the participation of the Association of Fishermen “Fronteras Vivas”. In general, the population density extrapolated to the lake area was 1.29 fish/ha. Of these, the density of progenitors in the lake was 1.19 fish/ha. Also, male animals had total length, standard length and total weight higher than females and it was observed that the spawning period occurred in synchronization with the start of the growing of the hydrological regime. The average number of oocytes produced by females of silver arowana in the study area was 201 and the sex ratio was equilibrated. Furthermore, the study shows the capacity of production of the lake. In order to this the water lever influenced in the production of baby arowanas. It is important to continue studying the species for regulate the fishing and recover populations.Keywords: baby arowana; production; ornamental trade; length of first sexual maturity; fishing.Devido à importância da pesca ornamental de aruanã, e da lagoa Lago Grande como uma das principais áreas para a captura de alevinos de aruanã no Peru, o presente estudo tive como objetivo avaliar a produtividade e as características reprodutivas na espécie na lagoa, a mesma que está localizada na bacia baixa do Rio Putumayo e representa uma das áreas de pesca preferidas pela importante população de aruanã que a habitam. Foram feitas análises de densidade populacional, biometria, maturidade sexual, desova, fecundidade, proporção sexual, níveis da água na lagoa e sobre a produção de alevinos de aruanã. O estudo foi desenvolvido entre março a julho de 2012 e as atividades foram realizadas em parceria com a Agrupação de Pescadores “Fronteras Vivas”. De modo geral, a densidade populacional extrapolada à área da lagoa foi de 1.29 peixes∕ha. Daqueles, a densidade de progenitores na lagoa foi de 1.19 peixes∕ha. Além disso, os machos tiveram comprimento total e padrão e peso total maior do que as fêmeas, e foi observado que o período de desova ocorreu em sincronia com o início da crescente no nível das águas. A média de oocitos produzidos por fêmeas de aruanã foi de 201 e a proporção sexual foi equilibrada. Assim mesmo, o estudo mostra a capacidade de produção da lago. Nesse sentido, o nível da água influenciou na produção de alevinos de aruanã. É importante continuar os estudos da espécie para regulamentar a pesca e recuperar populações.Palavras-chave: alevinos de aruanã, produção, comércio ornamental, comprimento de primeira maturidade sexual, pesca
Phenomenological Implications of Supersymmetry Breaking by the Dilaton
We investigate the low energy properties of string vacua with spontaneously
broken supersymmetry by a dilaton -term. As a consequence of the
universal couplings of the dilaton, the supersymmetric mass spectrum is
determined in terms of only three independent parameters and more constrained
than in the minimal supersymmetric Standard Model. For a -term induced by
the \K\ potential the parameter space becomes two-dimensional; in the allowed
regions of this parameter space we find that most supersymmetric particles are
determined solely by the gluino mass. The Higgs is rather light and the
top-quark mass always lower than 180 GeV.Comment: 14 pages, (4 figures not included, available upon request),
CERN-TH.6856/93 (In the previous version of this article the gaugino masses
were given incorrectly. As a consequences the quantitative analysis of the
low energy spectrum changes.
Biodegradable mulching vs traditional polyethylene film for sustainable solarization: Chemical properties and microbial community response to soil management
Abstract Soil solarization is usually performed with polyethylene plastic films, which are often disposed of by taking them to landfills, burying them in soil, burning them or occasionally recycling them, and these approaches have a great impact on the environment. Therefore, the use of biodegradable films seems to be an interesting eco-sustainable alternative to traditional films. The effect of soil solarization carried out by using biodegradable mulch or traditional polyethylene plastic film was determined under greenhouse conditions. The response of the soil was assessed by chemical determinations and microbiological culture-dependent and culture-independent approaches to evaluate the microbial biodiversity, biological status and quality of the soil. The biodegradable film avoided a high ammonia concentration in the soil, thanks to both lower soil water content and slightly lower temperature than polyethylene film, and these conditions probably have been optimal for growth of nitrifying bacteria, which were more efficient in BIO, as highlighted not only by lower ammonia value but also by higher nitrate value. Both films did not affect organic matter and total nitrogen content. Moreover, the modifications of the environmental and ecological conditions associated with the different film covers applied to the soils affected prokaryotic and eukaryotic populations, leading to the establishment of a new dominant microbial community. Interestingly, microbiological analyses highlighted a different behavior modulated with the two films indicating different times of recovery post stress. Overall, the results highlighted the potential of biodegradable film that appears to be a suitable replacement for traditional polyethylene plastic film for soil solarization, with great environmental benefits
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