3,375 research outputs found
Cacao agroforestry systems do not increase pest and disease incidence compared with monocultures under good cultural management practices
Pests and diseases threaten cacao production worldwide. Agroforestry systems are traditionally seen by farmers as one of the causes of increased pest and disease incidence, in contrast with full-sun monocultures. Cultural management practices - e.g. regular tree pruning, frequent pod harvest, regular removal of infested pods, weed management - have been reported to be crucial for pest and disease management. We performed two experiments for the purpose of assessing the effect of (i) different cacao production systems, and (ii) the frequency of harvest and removal of infested pods on the incidence of pests and diseases and on the cacao yield. The first experiment was performed in a long-term system comparison trial in Bolivia, where data on pest and disease incidence were recorded for three years in five production systems: two monocultures and two agroforestry system under organic and conventional farming, and one successional agroforestry system, i.e. a high tree density multi-strata system. Pest and disease management did not differ between systems and relied on cultural management practices. Overall, the incidence of pests and diseases did not differ between production systems, which indicated they were not the driver of yield differences between them. Across production systems, only 14% of the pods were affected by pests and diseases; 70% of these were affected by frosty pod rot. More than 80% of the pods infected by frosty pod rot were removed before the sporulation phase. In the second experiment, the effects of the frequency of harvest and removal of infected pods - every 15 days versus every 25 days - on pest and disease incidence and yield were tested in four farmersâ fields. Fortnightly harvest and diseased pod removal significantly decreased disease incidence and increased cacao yield, by 25% and 46% respectively. Our results show that cacao agroforestry systems do not increase pest and disease incidence compared with monocultures when good cultural management practices are implemented, which, in turn, can increase the productivity of the cacao plantations
Valores semĂĄntico-pragmĂĄticos de aĂșn
Els diccionaris i les gramĂ tiques solen distingir
entre aĂșn temporal i aun amb valors de tipus modal-concessiu. Segons aquesta caracteritzaciĂł,
el primer Ă©s commutable per todavĂa i porta accent grĂ fic mentre que el segon no sâaccentua i Ă©s
reemplaçable per hasta, incluso o siquiera. La multiplicitat de funcions i valors semĂ ntics dâaĂșn,
ja advertida per Bello (§1217), ha portat alguns autors a incloureâl en el grup de les âpartĂculesâ
(Pavon Lucero 1999), una metaclasse que engloba preposicions, adverbis i conjuncions. Altres
estudis (SĂĄnchez LĂłpez 1999, Leonetti 2007 i NGRALE 2009) lâhan ubicat dins la subclasse
dels focalitzadors, la funciĂł dels quals Ă©s posar de relleu lâestructura informativa de lâoraciĂł. En
aquest treball, ens interessa plantejar que totes dues variants âaĂșn temporal / aun concessiuâ
no representen un contrast dicotĂČmic sinĂł que comparteixen un valor quantificacional que es
vincula amb el carĂ cter escalar que tambĂ© tĂ© aquest mot. Aquesta similitud sâevidencia en els casos
en quĂš aquesta partĂcula incideix sobre una comparaciĂł i resulta possible tant la substituciĂł per
todavĂa com per incluso.Spanish dictionaries and grammar textbooks
usually describe the word aĂșn (even) as an expression of time and aun as an expression of
modality (concession). In the first case, it is interchangeable with todavĂa (yet) and it carries an accent mark. In the second case, the word carries no accent and it is interchangeable with hasta,
incluso or siquiera (until, even, (not) even). Because of its wide variety of functions and semantic
values, as pointed out much earlier by Bello (§1217), some grammarians (Pavón Lucero (1999)
have included aĂșn in the group of the so called âparticlesâ, a group formed by some prepositions,
adverbs and conjunctions. Other authors (SĂĄnchez LĂłpez 1999, Leonetti 2007 y NGRALE 2009)
have placed it within the subgroup of focus words, i.e. words that show the sentence information
structure. This paper points out that there is no sharp contrast between these two values â
aĂșn/aun expressing time or concessionâ and that they actually share a sense of quantification
related to the wordâs incremental character. This shared value is clearly seen in sentences with a
comparative structure, in which cases this word can be equally replaced by todavĂa or incluso
Articulating signs in the city
Diego Ferrari will introduce photographic projects evolving from
his artistic concerns and research, and which have
also informed his teaching of fine art approaches to
photography. In his conception, photography becomes
a playful process which allows for an interdisciplinary
approach between photography, performance
art/âhappeningsâ and the public space. The act of
photographing becomes itself performative and
challenges ideas of public and private space, and
what can and cannot beenacted in the city. Ferrari
will present photography from projects in Berlin,
London, Barcelona and Johannesburg, where he has
worked with various universities and institutions such
as Central Saint Martins College of Art and Design,
Goldsmiths and Kingston Universities in London,
Elisava Barcelona School, the House of World Cultures
in Berlin and the Goethe Institute in South Africa. The
work elicits an ambiguity between personal subjectivity
and social objectivity as a fertile platform to reflect on
the psychological as well as bodily and metaphysical
relationship to the notion of public space. Cities of Light: Barcelona is co-organised by Diego Ferrari, Urban Photographers Association (UPA) / Kingston University, UK and Elisava University, Barcelona; Laura Cuch, Urban Photographers Association (UPA) / Goldsmiths, University of London and University College London; and Jean McNeil, University of East Anglia, UK; in collaboration with Institut dâEstudis FotogrĂ fics de Catalunya
Challenges in the development and growth of small for gestational age newborns
Introduction: Being born with low birth weight (less than 2.500 gr) is considered a public health
problem, with an overall world rate of about 14%. Low birth weight may result from a premature birth
(< 37 weeks of gestation), from several causes of intra-uterine growth restriction or from a combination
of both.
Areas covered: We described how, if weight and/or length at birth are not adequate for gestational
age, the newborn is considered âsmall for gestational ageâ and may present several growth, hormonal
and developmental peculiarities, possibly due to the growth restriction developed during pregnancy.
Expert commentary: We provide a description of the possible mid-term consequences of being born
small for gestational age and how to follow and provide care for these babies from a multidisciplinary
point of view
Analysis of the Catecholaminergic Phenotype in Human SH-SY5Y and BE(2)-M17 Neuroblastoma Cell Lines upon Differentiation
Human cell lines are often used to investigate cellular pathways relevant for physiological or pathological processes or to evaluate cell toxicity or protection induced by different compounds, including potential drugs. In this study, we analyzed and compared the differentiating activities of three agents (retinoic acid, staurosporine and 12-O-tetradecanoylphorbol-13-acetate) on the human neuroblastoma SH-SY5Y and BE(2)-M17 cell lines; the first cell line is largely used in the field of neuroscience, while the second is still poorly characterized. After evaluating their effects in terms of cell proliferation and morphology, we investigated their catecholaminergic properties by assessing the expression profiles of the major genes involved in catecholamine synthesis and storage and the cellular concentrations of the neurotransmitters dopamine and noradrenaline. Our results demonstrate that the two cell lines possess similar abilities to differentiate and acquire a neuron-like morphology. The most evident effects in SH-SY5Y cells were observed in the presence of staurosporine, while in BE(2)-M17 cells, retinoic acid induced the strongest effects. Undifferentiated SH-SY5Y and BE(2)-M17 cells are characterized by the production of both NA and DA, but their levels are considerably higher in BE(2)-M17 cells. Moreover, the NAergic phenotype appears to be more pronounced in SH-SY5Y cells, while BE(2)-M17 cells have a more prominent DAergic phenotype. Finally, the catecholamine concentration strongly increases upon differentiation induced by staurosporine in both cell lines. In conclusion, in this work the catecholaminergic phenotype of the human BE(2)-M17 cell line upon differentiation was characterized for the first time. Our data suggest that SH-SY5Y and BE(2)-M17 represent two alternative cell models for the neuroscience field
Assigning UPDRS Scores in the Leg Agility Task of Parkinsonians: Can It Be Done through BSN-based Kinematic Variables?
In this paper, by characterizing the Leg Agility (LA) task, which contributes
to the evaluation of the degree of severity of the Parkinson's Disease (PD),
through kinematic variables (including the angular amplitude and speed of
thighs' motion), we investigate the link between these variables and Unified
Parkinson's Disease Rating Scale (UPDRS) scores. Our investigation relies on
the use of a few body-worn wireless inertial nodes and represents a first step
in the design of a portable system, amenable to be integrated in Internet of
Things (IoT) scenarios, for automatic detection of the degree of severity (in
terms of UPDRS score) of PD. The experimental investigation is carried out
considering 24 PD patients.Comment: 10 page
On the Hydrodynamic Equilibrium of a Rod in a Lattice Fluid
We model the behavior of a big (Brazil) nut in a medium of smaller nuts with
a stochastic asymmetric simple exclusion dynamics of a polymer-monomer lattice
system. The polymer or `rod' can move up or down in an external negative field,
occupying N horizontal lattice sites where the monomers cannot enter. The
monomers (at most one per site) or `fluid particles' are moving symmetrically
in the horizontal plane and asymmetrically in the vertical direction, also with
a negative field. For a fixed position of the rod, this lattice fluid is in
equilibrium with a vertical height profile reversible for the monomers' motion.
Upon `shaking' (speeding up the monomers) the motion of the `rod' dynamically
decouples from that of the monomers resulting in a reversible random walk for
the rod around an average height proportional to log N.Comment: 19 pages, 2 figure
Irreversible reinsurance: Minimization of Capital Injections in Presence of a Fixed Cost
We propose a model in which, in exchange to the payment of a fixed
transaction cost, an insurance company can choose the retention level as well
as the time at which subscribing a perpetual reinsurance contract. The surplus
process of the insurance company evolves according to the diffusive
approximation of the Cram\'er-Lundberg model, claims arrive at a fixed constant
rate, and the distribution of their sizes is general. Furthermore, we do not
specify any specific functional form of the retention level. The aim of the
company is to take actions in order to minimize the sum of the expected value
of the total discounted flow of capital injections needed to avoid bankruptcy
and of the fixed activation cost of the reinsurance contract. We provide an
explicit solution to this problem, which involves the resolution of a static
nonlinear optimization problem and of an optimal stopping problem for a
reflected diffusion. We then illustrate the theoretical results in the case of
proportional and excess-of-loss reinsurance, by providing a numerical study of
the dependency of the optimal solution with respect to the model's parameters.Comment: 23 pages, 8 figure
Integration of Wi-Fi mobile nodes in a Web of Things Testbed
Abstract The Internet of Things (IoT) is supposed to connect billions of devices to the Internet through IP-based communications. The main goal is to foster a rapid deployment of Web-enabled everyday objects, allowing end users to manage and control smart things in a simple way, by using Web browsers. This paper focuses on the integration of Wi-Fi nodes, hosting HTTP resources, into a Web of Things Testbed (WoTT). The main novelty of the proposed approach is that the WoTT integrates new nodes by using only standard mechanisms, allowing end-users to interact with all Smart Objects without worrying about protocol-specific details
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