185 research outputs found
Soil quality and fertility in sustainable agriculture, with a contribution to the biological classification of agricultural soils
Soils and crops are particularly vulnerable to climate change and environmental stresses. In many agrosystems, soil biodiversity and ecosystem services provided by soils are under threat from a range of natural and human drivers. Agricultural soils are often subject to agronomic practices that disrupt soil trophic networks and make soils less productive in the long term. In this scenario, sustainable soil use aimed at improving plant/root status, growth and development plays a crucial role for enhancing the biological capacity of agricultural soils. This commentary paper is divided into the following four main sections: (i) the contentious nature of soil organic matter; (ii) soil biological quality/fertility; (iii) soil classification; and, (iv) which agricultural practices can be defined as sustainable? The published literature was analyzed within a holistic framework, with agrosystems considered as living systems where soil, vegetation, fauna and microorganisms co-evolve and are reciprocally influenced. Ultimately, this article will suggest a better stewardship of agricultural soils as a natural capital
Vertical distribution of Collembola (Hexapoda) and their food resources in organic horizons of beech forests
Hubungan Kepribadian Tipe-d Dengan Koping Klien Akne Vulgaris Di Jurusan Keperawatan Politeknik Kesehatan Kemenkes Manado
; This study aims to identify the relationship of type-D personality with clients coping acne vulgaris. The research method using descriptive analytic cross sectional design, the 120 respondents polytechnic nursing students of Department of Health MoH Manado, period study from April to July 2014. The instrument used was a questionnaire-type-D personality and coping questionnaire. Univariad analysis using frequency distributions are presented in tables and bivariate analysis using Chi-Square. The results of Chi-square analysis with significance level of 95% at α 5% (α = 0.05), obtained by X ÂČ = 13.308 with p (asypm.sig) = 0.000, <0.005, means that there is a significant association between type-D personality in coping clients of acne vulgaris. Conclusion: Type-D personality proved significantly associated with clients coping acne vulgaris, and individuals with a type-D personality tend to have maladaptive coping. Suggestion: the need for student research development of type-D personality and motivation in facing the problem of acne vulgaris
Fast algorithms for handling diagonal constraints in timed automata
A popular method for solving reachability in timed automata proceeds by
enumerating reachable sets of valuations represented as zones. A na\"ive
enumeration of zones does not terminate. Various termination mechanisms have
been studied over the years. Coming up with efficient termination mechanisms
has been remarkably more challenging when the automaton has diagonal
constraints in guards.
In this paper, we propose a new termination mechanism for timed automata with
diagonal constraints based on a new simulation relation between zones.
Experiments with an implementation of this simulation show significant gains
over existing methods.Comment: Shorter version of this article to appear in CAV 201
Wodzicki Residue for Operators on Manifolds with Cylindrical Ends
We define the Wodzicki Residue TR(A) for A in a space of operators with
double order (m_1,m_2). Such operators are globally defined initially on R^n
and then, more generally, on a class of non-compact manifolds, namely, the
manifolds with cylindrical ends. The definition is based on the analysis of the
associate zeta function. Using this approach, under suitable ellipticity
assumptions, we also compute a two terms leading part of the Weyl formula for a
positive selfadjoint operator belonging the mentioned class in the case
m_1=m_2.Comment: 24 pages, picture changed, added references, corrected typo
TerrHum: an iPhone app for classifying forest humipedons.
The knowledge of a little number of specific terms is necessary to investigate and describe the forest topsoils: diagnostic components, diagnostic organic and organic-mineral horizons and the 17 series of humus horizons composing all the observed real forest not submerged topsoils. Diagnostic horizons are grouped in humus forms, which represent five humus systems. To become a good topsoil investigator is then only a question of field experience. No mean to do otherwise: you must go in the field with a blade and a good manual and put your hand in the soil. You have to make a hole and to observe on your knee a wall of the pit, from the top to the bottom, detecting all the characters that you find indicated in the manual. At the beginning you will be discouraged, things change from a site to another and never are exactly as in the manual. After few days of difficult survey, you will be able to know your soil even without doing a hole. Be patient and follow what it is indicated in the published first eight articles of Humusica (http://intra.tesaf.unipd.it/people/zanella/hmanual.html). On the poster, you find some examples of diagnostic properties of forest topsoils, and a dichotomy key of classification, you can copy paste and take with you in the field. An iPhone application (Terrhum) allows to bring in the field the necessary information for a fast classification of the topsoil
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