521 research outputs found
Tolerância do capim marandu ao excesso de ferro e manganês
In soaked soils there is an increase in the availability of iron and manganese. Thus, it becomes important to investigate the tolerance levels of plants to excess of these nutrients. The objective was to evaluate the tolerance of Urochloa brizantha cv. Marandu cultivated in nutrient solution with different levels of iron and manganese. The experimental design was completely randomized with seven treatments and four replications. The treatments consisted of a nutrient solution and consisted of: 1- adequate concentration of Fe (8.22 mM) and Mn (2.05 mM); 2– Fe, four times the adequate concentration; 3– Fe, eight times the adequate concentration; 4– Mn, four times the adequate concentration; 5– Mn, eight times the adequate concentration; 6– Fe and Mn, four times the appropriate concentration, and; 7– Fe and Mn, eight times the appropriate concentration. The variables evaluated were visual diagnosis (symptomatology), shoot height, root volume, Fe and Mn content in shoots and dry mass production. Grass plants were not tolerant to excess Fe and Mn. The excess of nutrients promoted less development of the root system, with a reduction in volume and dry mass, and the treatment with the highest dose of nutrients resulted in the lowest values. Grass plants were sensitive to the increase in nutrient concentrations, showing reductions in total dry mass production of 55% for treatment with the application of the highest concentration of nutrients in relation to the adequate dose of Fe and Mn.Em solos encharcados há aumento na disponibilidade de ferro e de manganês. Dessa forma, torna-se importante investigar os nÃveis de tolerância das plantas ao excesso desses nutrientes. We aimed to evaluate Urochloa brizantha cv. Marandu tolerance when grown in nutrient solution with different levels of iron and manganese. The experimental design was completely randomized with seven treatments and four repetitions. Os tratamentos foram constituÃdos por solução nutritiva e consistiram em: 1- concentração adequada de Fe (8,22 mM) e de Mn (2,05 mM); 2– Fe, quatro vezes a concentração adequada; 3– Fe, oito vezes a concentração adequada; 4– Mn, quatro vezes a concentração adequada; 5– Mn, oito vezes a concentração adequada; 6– Fe e Mn, quatro vezes a concentração adequada, e; 7– Fe e Mn, oito vezes a concentração adequada. As variáveis avaliadas foram a diagnose visual (sintomatologia), altura de parte aérea, volume de raÃzes, teor de Fe e Mn na parte aérea e produção de massa seca. As plantas de capim não foram tolerantes ao excesso de Fe e Mn. O excesso dos nutrientes promoveu menor desenvolvimento do sistema radicular, com redução no volume e massa seca, sendo que o tratamento com a maior dose dos nutrientes foi o que resultou nos menores valores. As plantas de capim foram sensÃveis ao aumento das concentrações dos nutrientes, apresentando reduções na produção de massa seca total de 55% para tratamento com aplicação da maior concentração dos nutrientes em relação à dose adequada de Fe e Mn
Le competenze-di-cittadinanza: sondaggi su Dewey
The article exposes the relationship between the current debate on the key-skills of citizenship, as mean and aim of contemporary citizen’s education, and John Dewey’s theories about education and society, bound together by purpose of participatory democracy and active citizenship. Research, scientific attitude and democracy are the most significant and central points of Dewey's thought. These issues and problems are today found in the delineation of the key-skills of citizenship through scholastic subjects as a teaching/learning practice
ART. 1224 C.C., MAGGIOR DANNO DEL CREDITO DI IMPRESA DA INADEMPIMENTO DELLE OBBLIGAZIONI PECUNIARIE
Lo studio della tematica dell’inadempimento consente, per\ud
sua natura, di apprezzare e valorizzare l’approccio metodologico e\ud
sistematico di quella parte della dottrina che predilige una analisi\ud
procedimentale e funzionale degli istituti giuridici. Ogni istituto\ud
deve essere studiato sia in relazione alla struttura che in relazione\ud
alla funzione: il rapporto obbligatorio e l’inadempimento non\ud
sfuggono a tale impostazione1. Può anzi affermarsi che proprio lo\ud
studio della vicenda legata all’inadempimento e degli effetti che\ud
tale fattispecie produce sul rapporto rimasto ineseguito, confermi\ud
la necessità di una valutazione di carattere funzionale
Sodium fraction excretion rate in nocturnal enuresis correlates with nocturnal polyuria and osmolality
Abstract: Purpose: We verify the sodium fraction excretion rate (FE Na) and potassium fraction excretion WE K) rates in monosymptomatic nocturnal enuresis. We also correlate FE Na and FE K to urinary osmolality, nocturnal polyuria and vasopressin in the same population.
Materials and Methods: A total of 438 children 6 to 15 years old (mean age 9.7) presenting with monosymptomatic nocturnal enuresis were recruited from different centers. Inclusion criteria were 3 or greater wet nights a week, no daytime incontinence and no treatment in the previous 2 months. Exclusion criteria were cardiopathy, endocrinopathy, psychiatric problems and urinary tract abnormalities. Micturition chart, diurnal (8 am to 8 pm) and nocturnal (8 pm to 8 am) urine collection, including separate diuresis volumes, (Na, K and Ca) electrolytes and osmolality were evaluated, as well as serum electrolytes, creatinine and nocturnal (4 am) vasopressin. Diurnal and nocturnal FE K and FE Na were calculated. ANOVA test, chi-square test, Student's t test and Pearson correlation test were used for statistical analysis.
Results: Nocturnal polyuria (diurnal to nocturnal diuresis ratio less than 1) was found in 273 children (62.3%, group I and nocturnal urine volumes were normal in 165 with enuresis (37.7%, group 2). Nocturnal FE Na was abnormal in 179 children (40.8%), including 118 in group 1 (43.2%) and 61 in group 2 (36.9%) (chi-square not significant). FE Na was also increased in nocturnal versus daytime diuresis (Student's t test p < 0.001). In group 1 nocturnal FE Na correlated with nocturnal diuresis (Pearson correlation p = 0.003, r = +0.175), while daytime FE Na and nocturnal FE Na correlated with diurnal diuresis (Pearson correlation p = 0.001, r = +0.225 and Pearson correlation p = 0.001, r = +0.209, respectively). In group 2 nocturnal FE Na did not correlate with diuresis (Pearson correlation p = 0.103, r = +0.128) but correlated with vasopressin values (Pearson correlation p = 0.042, r = -0.205). Urine osmolality was reduced in 140 children (31.9%) and correlated with nocturnal diuresis (Pearson correlation p = 0.003, r = -0.321). Vasopressin was decreased in 332 children (75.8%, 62.6% in group 1 and 13.2% in group 2). No significant difference was found between sexes and age of enuretic subgroups.
Conclusions: Nocturnal FE Na correlates with nocturnal diuresis, whereas daytime FE Na does not. FE K in daytime and nighttime diuresis does not statistically differ in nocturnal polyuric and nonpolyuric enuretic groups. Osmolality correlates with nocturnal diuresis, and vasopressin at 4 am was lower in the nocturnal polyuric group. The hypothesis of a subset of enuretic patients presenting with nocturnal polyuria associated with high nocturnal natriuria and low vasopressin values has been confirmed
DETECTION OF MICROPLASTICS IN MARINE SEDIMENTS: RESULTS FROM THREE ITALIAN COASTS
The presence and dangerousness of microplastics (MPs) in aquatic environments is universally
recognized. The MPs criticalities are tied to their small size (less than 5mm), which make most
of the treatment processes used for other waste ineffective, to their persistence and poor
degradability and to their presence in large and ever-increasing quantities.
This research deals with the separation and identification of MP particles present within
sediments of sea sand sampled in three different Italian coasts: Imperia (Liguria), Metaponto
(Basilicata) and Villa San Giovanni, (Calabria). Comparison between sediment sampled from
less frequented beaches and tourist ones were made too, to verify the relation with tourism or
any other sources of MP pollution. The complexity of collecting and analyzing real sample, the
proper counting and recognition of all MPs in the sample were deeply discussed.
The importance of grain size classification and separation was highlighted [1]. The density
separation method with saline solution (NaCl) was used to analyze the samples. In addition, a
CaCl solution was tested to separate MP particles with higher density. Electrostatic separation
method was tested too, separating the conductive fraction to the non-conductive (containing
MPs) one. An increasing of MP content/g of sediment was obtained comparing the nonconductive
fraction with samples subjected to densimetric separation with NaCl solution
(reaching also a 82% of variation). This method could be used to reduce the volume of samples,
optimizing the MP identification and counting; however, other tests could be carried out in the
future taking into account that a loss of material due to the apparatus should be considered.
Visual identification under microscope with a UV lamp was used to identify and count
fluorescent MPs particles [2][3], subsequently verified with spectroscopy analyses using FTIR
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