bluuebunny/crossref_metadata_2025 huggingface dataset:
Calcium-Sensing Receptor Autoantibodies and Idiopathic Hypoparathyroidism
Authors: Tomar Neeraj , Gupta Nandita , Goswami Ravinder
Published: July 2013

Context:

Data on calcium-sensing receptor autoantibodies (CaSRAbs) in hypoparathyroidism are variable.

Objective:

We assessed the prevalence and significance of CaSRAbs in idiopathic hypoparathyroidism.

Design:

This was a case-control study.

Subjects:

One hundred forty-seven patients with idiopathic hypoparathyroidism treated during 1998–2011 in a tertiary care setting and 348 controls [healthy, n = 199; type 1 diabetes mellitus (T1DM), n = 99; and chronic lymphocytic thyroiditis (CLT), n = 50] participated in the study.

Methods:

CaSRAb assays included Western blot with CaSR protein expressed in Escherichia coli or human embryonic kidney (HEK)-293 cells, immunoprecipitation (IP) using in vitro-transcribed/translated protein, and indirect immunofluorescence on HEK293-CaSR. Functional significance was assessed by ERK1/2 phosphorylation. PTH and CaSR genes were sequenced for mutations.

Results:

E coli-Western blot assay revealed 16.3% CaSRAb positivity in idiopathic hypoparathyroidism, which was comparable with healthy subjects and CLT but significantly less than the T1DM controls. The prevalence of CaSRAbs on HEK293-Western blot (24.5%) against 150 kDa and/or 168 kDa protein in hypoparathyroidism was significantly higher than the healthy subjects, T1DM, and CLT. IP assay showed CaSRAbs in 12.9% of the hypoparathyroid patients but not in controls. The sensitivity and specificity of CaSRAbs in E coli and HEK-293-CaSR Western blot and IP assays were 16.3% and 83.1%, 24.5% and 88.9%, and 12.9% and 100%, respectively, and 42.1% of the cases detected were common in the IP assay and HEK293-Western blot. Duration of illness and coexistent autoimmunity were similar in patients with and without CaSRAbs. The CaSRAb-positive sera showed no immunofluorescence and phosphorylated ERK1/2 activity. The CaSR gene sequence was normal in all patients. One of the patients showed a novel p.Met1_Asp6del mutation in the signal peptide region of the PTH gene.

Conclusion:

IP performed the best in detecting CaSRAbs in 12.9% of hypoparathyroid patients. Although CaSRAbs were functionally inert, its clinical relevance remains due to 100% specificity. Limited prevalence of CaSRAb suggests heterogeneity in the etiology of idiopathic hypoparathyroidism or the presence of CaSR epitopes other than those measured in the current study.
Which U.S. Market Interactions Affect CEO Pay? Evidence from UK Companies
Authors: Gerakos Joseph J. , Piotroski Joseph D. , Srinivasan Suraj
Published: July 2013

This paper examines how different types of interactions with U.S. markets by non-U.S. firms are associated with higher levels of CEO pay, greater emphasis on incentive-based compensation, and smaller pay gaps with U.S. firms. Using a sample of CEOs of UK firms and using both broad cross-sectional and narrow event-window tests, we find that capital market relationship in the form of a U.S. exchange listing is related to higher UK CEO pay; however, the effect is similar when UK firms have a listing in any foreign country, implying a foreign listing effect not unique to the United States. Product market relationships measured by the extent of sales in the United States by UK companies are associated with higher pay, greater use of U.S.-style pay arrangements, and a reduction in the U.S.–UK pay gap. The product market effect is incremental to the effect of a U.S. exchange listing, the extent of the firm's non-U.S. foreign market interactions, and the characteristics of the executive. The U.S.–UK CEO pay gap reduces in UK firms that make U.S. acquisitions. Furthermore, the firm's use of a U.S. compensation consultant increases the sensitivity of UK pay practices to U.S. product market relationships.

This paper was accepted by Gérard P. Cachon, accounting.
Can Margin Differences in Vertical Marketing Channels Lead to Contracts with Slotting Fees?
Authors: Dhar Tirtha
Published: July 2013

In this paper, we show that slotting fees can be part of an equilibrium solution if per-unit downstream margin is smaller than the per-unit upstream margin. In recent literature, a similar margin-based argument is made by Klein and Wright (2007), whereas intense downstream retail competition coupled with high upstream margin causes upstream manufacturers to offer slotting fees for promotional shelf space. In this paper, we generalize this argument and show that it is possible to have the margin-based argument without any downstream retail competition and competition between products within a retail chain. Interestingly we show that slotting fees will be larger if the products sold by a retailer are complements rather than substitutes. Using a model of a channel bargaining game, we also provide the necessary and sufficient conditions for the existence of slotting fees and show that for contracts with slotting fees under full vertical coordination, upstream marginal cost functions need to be increasing. Broadly, our findings provide new insights into the strategic role of downstream product assortment on equilibrium-marketing-channel contracts with slotting fees.

This paper was accepted by J. Miguel Villas-Boas, marketing.
Simultaneous vs. Sequential Group-Buying Mechanisms
Authors: Hu Ming , Shi Mengze , Wu Jiahua
Published: July 2013

This paper studies the design of group-buying mechanisms in a two-period game where cohorts of consumers arrive at a deal and make sign-up decisions sequentially. A firm can adopt either a sequential mechanism where the firm discloses to second-period arrivals the number of sign-ups accumulated in the first period, or a simultaneous mechanism where the firm does not post the number of first-period sign-ups and hence each cohort of consumers faces uncertainty about another cohort's size and valuations when making sign-up decisions. Our analysis shows that, compared with the simultaneous mechanism, the sequential mechanism leads to higher deal success rates and larger expected consumer surpluses. This result holds for a multiperiod extension and when the firm offers a price discount schedule with multiple breakpoints. Finally, when the firm can manage the sequence of arrivals, it should inform the smaller cohort of consumers first.

This paper was accepted by J. Miguel Villas-Boas, marketing.
A Person–Organization Discontinuity in Contract Perception: Why Corporations Can Get Away with Breaking Contracts But Individuals Cannot
Authors: Haran Uriel
Published: July 2013

Most legal systems in the world follow the principle of corporate personhood, which grants organizations the same legal status as natural persons. Although debate over the notion of corporate personhood has been fierce, whether and how this principle is applied in people's beliefs and intuitions has yet to be empirically examined. This work addresses the gap in the literature, in the context of formal contracts. While contracts are typically seen as either morally binding promises or morally neutral business instruments, the data presented here show that contracts of individuals are associated more strongly with promises than are contracts of organizations. As a result, breach of contract by an individual is seen as a moral transgression. The same behavior by an organization, however, is viewed more as a legitimate business decision. This paper also finds that contractual obligations should be phrased in “promise” terms to eliminate this person–organization discontinuity.

Data, as supplemental material, are available at http://dx.doi.org/10.1287/mnsc.2013.1745 .

This paper was accepted by Yuval Rottenstreich, judgment and decision making.
The NGO's Dilemma: How to Influence Firms to Replace a Potentially Hazardous Substance
Authors: Kraft Tim , Zheng Yanchong , Erhun Feryal
Published: July 2013

We study a nongovernmental organization's (NGO's) decisions when it attempts to remove a potentially hazardous substance from commercial use in a market with competing firms. Specifically, we determine under what market and regulatory conditions an NGO should target the industry versus the regulatory body to influence firms to replace the substance. We examine how the NGO's strategy changes as the NGO's pragmatism (i.e., the extent to which the NGO incorporates firms' profits into its decision making) increases. Our results demonstrate that when the NGO is less pragmatic, it should examine the existing market structure to determine whether to target the industry or the regulatory body. However, as the pragmatism of the NGO increases, the NGO should increasingly leverage the competition between firms to ensure that a replacement is available to consumers. We examine multiple extensions including varying the competition dynamics, the NGO targeting both the industry and the regulatory body, the time discounting of replacement costs, and a firm potentially lobbying to counteract an NGO's activism. We show that the potential for a firm to lobby can benefit consumers by motivating the NGO to exert more effort and increase the market sensitivity to a substance, thereby forcing the firm to replace.
Supermodularity and Affine Policies in Dynamic Robust Optimization
Authors: Iancu Dan A. , Sharma Mayank , Sviridenko Maxim
Published: July 2013

This paper considers a particular class of dynamic robust optimization problems, where a large number of decisions must be made in the first stage, which consequently fix the constraints and cost structure underlying a one-dimensional, linear dynamical system. We seek to bridge two classical paradigms for solving such problems, namely, (1) dynamic programming (DP), and (2) policies parameterized in model uncertainties (also known as decision rules), obtained by solving tractable convex optimization problems.

We show that if the uncertainty sets are integer sublattices of the unit hypercube, the DP value functions are convex and supermodular in the uncertain parameters, and a certain technical condition is satisfied, then decision rules that are affine in the uncertain parameters are optimal. We also derive conditions under which such rules can be obtained by optimizing simple (i.e., linear) objective functions over the uncertainty sets. Our results suggest new modeling paradigms for dynamic robust optimization, and our proofs, which bring together ideas from three areas of optimization typically studied separately—robust optimization, combinatorial optimization (the theory of lattice programming and supermodularity), and global optimization (the theory of concave envelopes)—may be of independent interest.

We exemplify our findings in a class of applications concerning the design of flexible production processes, where a retailer seeks to optimally compute a set of strategic decisions (before the start of a selling season), as well as in-season replenishment policies. We show that, when the costs incurred are jointly convex, replenishment policies that depend linearly on the realized demands are optimal. When the costs are also piecewise affine, all the optimal decisions can be found by solving a single linear program of small size (when all decisions are continuous) or a mixed-integer, linear program of the same size (when some strategic decisions are discrete).
On Solving Multistage Stochastic Programs with Coherent Risk Measures
Authors: Philpott Andy , de Matos Vitor , Finardi Erlon
Published: July 2013

We consider a class of multistage stochastic linear programs in which at each stage a coherent risk measure of future costs is to be minimized. A general computational approach based on dynamic programming is derived that can be shown to converge to an optimal policy. By computing an inner approximation to future cost functions, we can evaluate an upper bound on the cost of an optimal policy, and an outer approximation delivers a lower bound. The approach we describe is particularly useful in sampling-based algorithms, and a numerical example is provided to show the efficacy of the methodology when used in conjunction with stochastic dual dynamic programming.
An Infinite Server System with General Packing Constraints
Authors: Stolyar Alexander L.
Published: July 2013

We consider a service system model primarily motivated by the problem of efficient assignment of virtual machines to physical host machines in a network cloud, so that the number of occupied hosts is minimized.

There are multiple input flows of different type customers, with a customer mean service time depending on its type. There is an infinite number of servers. A server-packing configuration is the vector k = {ki}, where ki is the number of type i customers the server “contains.” Packing constraints must be observed; namely, there is a fixed finite set of configurations k that are allowed. Service times of different customers are independent; after a service completion, each customer leaves its server and the system. Each new arriving customer is placed for service immediately; it can be placed into a server already serving other customers (as long as packing constraints are not violated), or into an idle server.

We consider a simple parsimonious real-time algorithm, called Greedy, that attempts to minimize the increment of the objective function [Formula: see text], α > 0, caused by each new assignment; here Xk is the number of servers in configuration k. (When α is small, [Formula: see text] approximates the total number [Formula: see text] of occupied servers.) Our main results show that certain versions of the Greedy algorithm are asymptotically optimal, in the sense of minimizing [Formula: see text] in stationary regime as the input flow rates grow to infinity. We also show that in the special case when the set of allowed configurations is determined by vector-packing constraints, the Greedy algorithm can work with aggregate configurations as opposed to exact configurations k, thus reducing computational complexity while preserving the asymptotic optimality.
Bridging divides: Transference in the work of Lynne Heller
Authors: Hare Anastasia
Published: July 2013

This article discusses the work of Canadian artist Lynne Heller, specifically her project The Adventures of Nar Duell in Second Life begun in 2007. It examines her use of computational arts to blur distinctions between artistic media through the creation of digital and material composites in both physical and virtual spaces. Heller’s performances, which involve creating and navigating an avatar in Second Life, become material for her comic books and immersive, multimedia art installations. Moving in and out of formats, Heller bridges physical and alternative spaces and identities. An interview with the artist details the development of her multifaceted project and aesthetic complexity, particularly her artistic strategies and the ideas that inform her work, such as transference and the relationship with her avatar described as a mother-daughter bond. This article considers the implications of crafting within the virtual, and addresses aspects of materiality within these spaces, as well as modes of viewing, interaction and collaboration.
The low life epic: The Adventures of Nar Duell in Second Life
Authors: Heller Lynne
Published: July 2013

In this comic book style adventure, Lynne Heller’s intrepid but naive avatar, Nar Duell explores her world. The translation of the virtual adventures into comix style documentation is a natural expression of the experience of spending time in Second Life. The superficial and arbitrary nature of virtual life is mirrored in the ‘pow, bam, zap’ aesthetic of the printed page. Nar Duell’s adventures are transmogrified into narrative. The graphic novel supports the illusive nature of the work with the concrete and historical reference to print – a travel guide, and captures the essence and detail of what has been deemed alien and exotic by the outside world, and makes intimate that which is generally seen as inaccessible.
The actor, the designer and digital media: A case study at Formello
Authors: Zellner Dan
Published: July 2013

An account, from a performer’s perspective, of the REMAP/RITL workshop in Italy that details the various performer/media relationships encountered during the workshop. These experiences are identified using David Saltz’s taxonomy of performer/media relationships and described in the context of improvisational theatre and traditional Commedia dell’Arte mask work. Three digital media aspects of the work (‘the field’, ‘the object’ and ‘the mask’) are explored and conclusions drawn regarding approaches to digital media and areas for further research.
An intimate appearance: Black Box Production in the twenty-first century
Authors: Steck Rachel Kinsman
Published: July 2013

This article explores how, in an era where e-mail has discharged the letter or where Facebook replaces face-time with friends over a drink, where the lines between virtual reality and reality are colliding, can live performance aid in the creation of an activated citizenship? I believe to create an activated citizenship, we must first involve an activated spectatorship. Wrapped up in spectatorship, itself, are the elements of identity politics, subjectivity, ways of looking/seeing/gazing and cultural conventions. This research explores the relationship between the ways in which spectators look/see/view and the ways in which the production, working with the intimate relationship of performance-spectatorship in a black box theatre, manipulates the visual vocabulary, collapsing the boundaries of culture, performance and the real.
Lighting – A part of a changing aesthetics
Authors: White Christine
Published: July 2013

The advancements in, and the use of technology within, the theatre have resulted in some changes in directorial practice. As these advances in technology have changed the emphasis of the process of production, the prominence given to the director as sole ‘auteur’ of a piece of work has become diminished. The scenographic team is now more legitimately described as the ‘auteurs’ of a production. Another contributory factor for these developments has been the changes in theatre practice influenced both by European and Eastern European performance theories. This article explores the nature of these changes and influences and discusses the technology, which has offered greater scope for the manipulation of the stage image, in particular the use of lighting in scenography. The director is no longer a specialist in every area, ‘a man of the theatre’. He or she works collaboratively with the other artists in the production team in a much more democratic process of production. More than at any other time, the director works as another member of the team not only because he or she lacks knowledge, but because the technology has allowed considerable flexibility and the director’s ‘vision’ can be translated into many forms, materials and theories. The contribution of scenography to these changes, changes in acting styles and of what is expected within a performance space, has transformed the way in which an actor uses that space.
For example, the importance that Brecht placed on Caspar Neher’s designs for a cohesive performance structure (based on his sketches of/for the rehearsal process) and the relation of the actor to light (which Appia recognized as important) has resulted in stage technologies and scenography emerging as a partner of the actor and thus a new aesthetic.
The Stage is Set – or is it? – Production by Chris White, Derby Theatre, 20 March 2013
Authors: White Christine
Published: July 2013

The aim of the production was to perform the lighting research juxtaposing the historical research with special effects and lighting techniques. It experimented with performance and lighting styles to demonstrate the use of imagination and suggestion, and the emblematic and non-naturalistic in lighting effects from the Renaissance through to the interconnectedness of animation and live performance technologies.
Dynamic scores: Extending the parameter space of live performance
Authors: Sayer Tim
Published: July 2013

This article describes the rationale behind the development of a digital performance system that enables a musical ensemble or solo instrumentalist to interact with a generative and reactive visual score, projected in a cinematic environment. A partial feedback loop is setup between the performer and a projection of visual media, which allow the performer to perceive a response to their playing in certain aspects of the projection. The premise underpinning this piece runs far deeper than merely allowing acoustic instruments to interact with technology; it builds on the pioneering work of Benjamin Libet (1916–2007) and challenges the notion of volition and agency in the way performers react and respond to visual stimulus. The performances enabled by this system will not only provide an audience with a stimulating cinematic event but will also provoke the performers to engage in new and unexpected modes of musical behaviour. A prototype of this system is evaluated as a means of developing psychological and philosophical themes around the notion of freewill in interactive audio-visual performance.
‘Your Attention Please’: Media, spectacle and The Complex
Authors: Luber Steve
Published: July 2013

This article explores the problematic concept of attention in a mediatized culture. Using Blue Man Group (BMG)’s The Complex concert as a case study, I historicize and analyse discourse on attention and perception through phenomenological and deconstructive frames. I conclude with Michel Foucault’s conception of the heterotopia as the site for a productive analysis of The Complex show, a mediatized manifestation of other spaces, ones that defy focused attention and reveal encounters with and misfires from contemporary media consumption. The heterotopic multimedia concert calls the possibility of attention into question, and with this challenge the Blue Man provides a constructive re-evaluation of consumption and media culture.
The national culture references on the drama costumes: Are there limits?
Authors: Rocha Rosane Muniz
Published: July 2013

The purpose of this article is to analyse the use of local references in drama costume design, considering the possible limits when ‘showing yourself’ to others. From crossovers between the languages of Carnival and theatre, it brings up a local issue, but one that demands a global reflection, because it can lead any one of us, with any cultural background, from any country, to think about which references to choose and how to use them in drama costume design.
The place of place in telematic society
Authors: Starner Andrew
Published: July 2013

This article describes two works by American artist Robert Whitman working in the field of Expanded Cinema and avant-garde performance, with suggestions for contextualizing and interpreting them as intermedial theatre. These works, and the works of fellow theatre artists from the last 50 years, feature in a discussion of the ongoing question of how audiences relate to screens.
Beyond the gallery: The human foot as masterpiece of engineering, a work of art and window on our health
Authors: Oddey Alison
Published: July 2013

In this article, I want to examine the origins of my research, how the research process developed into an experiment of sorts, reflecting on that process and citing it as a potential hybridized form of cultural health interactive art exhibition event, focussing on the feet as they relate to health and well-being for public health engagement. In creating this unique live event, I wanted to interrogate, whether a cultural health intervention in an art gallery, can provide an alternative means to generate and promote public health awareness of self-preventive health care for self-help, wellness and well-being. I will discuss the feasibility of this type of health intervention, arguing that there is a need for these types of interventions to improve health through art, which can respond to local need within a community and bring about behaviour change.
I will explore how art can cause us to reflect on health, to understand how feet can have pressure points that affect well-being, and how art can enable people to reflect on health images and think about their own self-care and lifestyle choices. I will analyse how the human foot as masterpiece of engineering and art experience can affect people’s health, and whether those participating in the interactive art exhibition event engaged in better foot care after viewing the art. Thus, in terms of health literacy, health care innovation and exchange, whether the participants in the event are enabled to think further about foot care, health conditions in relation to reflexology, and to feel motivated to change their behaviour? I consider whether the dialogue that ensues among viewers in the gallery space plays a contributing role to illness prevention, health promotion and how the self-care of feet may contribute to a sense of wellness and well-being.
My thesis is that the art gallery event serves both as an artistic and a health promotion endeavour, demonstrated through the narratives of photography and interactive art. The liveness and performativity of the event (with two reflexologists present to conduct mini-taster sessions of individual client assessment during the exhibition) raises questions of how to evaluate the interaction and how to analyse the practical implications of the ideas that the exhibition is advancing. I consider the experiment from the perspective of both the academic and the complementary health therapist, particularly in relation to my role as a Senior Research Fellow at Nottingham Trent University, UK in the Narrative & Interactive Arts Department in the School of Art and Design, and in my role as a Reflexologist in private practice.
Reviews
Authors: Sporton Gregory , Sporton Gregory
Published: July 2013

Eugene Onegin, Kaspar Holten (dir.), London: The Royal Opera, 14 February 2013

Playing Cards 1: Spades, Robert Lepage (dir.), London: The Roundhouse, February–March 2013

In the Beginning was the End, Dreamthinkspeak, London: Somerset House, February–March 2013
Algebraic and rigid geometry on the Schottky problem
Authors: Ichikawa Takashi
Published: July 2013

We study the Schottky problem by giving the KP characterization
of Jacobian varieties among abelian varieties
in terms of their algebraic or nonarchimedean theta functions.
The regulation and function of the NUAK family
Authors: Sun Xianglan , Gao Ling , Chien Hung-Yu , Li Wan-Chun , Zhao Jiajun
Published: July 2013

AMP-activated protein kinase (AMPK) is a critical regulator of cellular and whole-body energy homeostasis. Twelve AMPK-related kinases (ARKs; BRSK1, BRSK2, NUAK1, NUAK2, QIK, QSK, SIK, MARK1, MARK2, MARK3, MARK4, and MELK) have been identified recently. These kinases show a similar structural organization, including an N-terminal catalytic domain, followed by a ubiquitin-associated domain and a C-terminal spacer sequence, which in some cases also contains a kinase-associated domain 1. Eleven of the ARKs are phosphorylated and activated by the master upstream kinase liver kinase B1. However, most of these ARKs are largely unknown, and the NUAK family seems to have different regulations and functions. This review contains a brief discussion of the NUAK family including the specific characteristics of NUAK1 and NUAK2.
Triiodothyronine induces lipid oxidation and mitochondrial biogenesis in rat Harderian gland
Authors: Santillo A , Burrone L , Falvo S , Senese R , Lanni A , Chieffi Baccari G
Published: July 2013

The rat Harderian gland (HG) is an orbital gland producing a copious lipid secretion. Recent studies indicate that its secretory activity is regulated by thyroid hormones. In this study, we found that both isoforms of the thyroid hormone receptor (Trα (Thra) and Trβ (Thrb)) are expressed in rat HGs. Although Thra is expressed at a higher level, only Thrb is regulated by triiodothyronine (T3). Because T3 induces an increase in lipid metabolism in rat HGs, we investigated the effects of an animal's thyroid state on the expression levels of carnitine palmitoyltransferase-1A (Cpt1a) and carnitine palmitoyltransferase-1B (Cpt1b) and acyl-CoA oxidase (Acox1) (rate-limiting enzymes in mitochondrial and peroxisomal fatty acid oxidation respectively), as well as on the mitochondrial compartment, thereby correlating mitochondrial activity and biogenesis with morphological analysis. We found that hypothyroidism decreased the expression of Cpt1b and Acox1 mRNA, whereas the administration of T3 to hypothyroid rats increased transcript levels. Respiratory parameters and catalase protein levels provided further evidence that T3 modulates mitochondrial and peroxisomal activities. Furthermore, in hypothyroid rat HGs, the mitochondrial number and their total area decreased with respect to the controls, whereas the average area of the individual mitochondrion did not change. However, the average area of the individual mitochondrion was reduced by ∼50% in hypothyroid T3-treated HGs, and the mitochondrial number and the total area of the mitochondrial compartment increased. The mitochondrial morphometric data correlated well with the molecular results. Indeed, hypothyroid status did not modify the expression of mitochondrial biogenesis genes such as Ppargc1a, Nrf1 and Tfam, whereas T3 treatment increased the expression level of these genes.
Produção e qualidade dos frutos de cultivares e seleções de pessegueiro na Serra da Mantiqueira
Authors: Souza Filipe Bittencourt Machado de , Alvarenga Ângelo Albérico , Pio Rafael , Gonçalves Emerson Dias , Patto Leonardo Silva
Published: July 2013

Objetivou-se avaliar a produção e atributos de qualidade de cultivares e seleções de pessegueiro nas condições da Serra da Mantiqueira. Um ensaio de competição foi implantado no município de Maria da Fé (MG), com 17 cultivares e seleções ('BRS Libra', 'Bolinha', 'Fla 88-13', 'Ouromel-2', 'Aurora-1', 'Jade', 'Aztec Gold', 'Tropical Beauty', 'Sensação', 'Chimarrita', 'Diamante', 'Maciel', Conserva 1122, Cascata 1015, Conserva 1050, Conserva 693 e Cascata 1056). O experimento foi implantado em 2006, no espaçamento de 6,0x4,0 m, com mudas enxertadas no porta-enxerto 'Okinawa'. As avaliações foram realizadas em três ciclos produtivos (2009, 2010 e 2011), analisando-se os aspectos fenológicos, produtivos e atributos de qualidade do fruto. Para 'Bolinha', Cascata 1015, 'Ouromel-2', Conserva 1050 e 'Tropical Beauty' não se observou alternância de produção. 'Ouromel-2', Conserva 1050 e 'Tropical Beauty' tiveram maior produção de frutos, com colheitas concentrando entre 13 de outubro e 16 de novembro. A cultivar Ouromel-2 teve atributos de qualidade mais adequados para o consumo ao natural, com menor acidez, boa firmeza de polpa e sólidos solúveis mais elevados. Conserva 1050 é boa opção para a indústria e 'Tropical Beauty' para dupla finalidade.
Filiação entre arenitos da formação Guará e sua cobertura pedológica no Rio Grande Do Sul
Authors: Medeiros Edgardo Ramos , Pedron Fabrício de Araújo , Reinert Dalvan José , Sccoti Anderson Augusto Volpato
Published: July 2013

As regiões oeste e sudoeste do Rio Grande do Sul, RS, destacam-se pela ocorrência de extensas áreas com solos frágeis desenvolvidos sobre sedimentos arenosos continentais do Mesozoico da Bacia do Paraná. O uso inadequado das terras tem acelerado o processo de arenização sobre essas áreas. Nesse caso, o conhecimento dos solos é fundamental para a seleção de práticas adequadas de manejo visando a sua sustentabilidade. Os objetivos deste trabalho foram entender a evolução e estabelecer a relação, em termos de filiação, entre a rocha e sua respectiva cobertura pedológica por meio de perfis desenvolvidos sobre os arenitos da Formação Guará no RS. Foram realizadas análises químicas, físicas, mineralógicas e morfológicas em dois perfis de Cambissolos Háplicos e um perfil de Argissolo Vermelho. Verificaram-se indícios de adição externa de materiais aos perfis estudados, principalmente ilmenita, oriunda da alteração de áreas com rochas vulcânicas básicas circunvizinhas. O aporte de material alóctone nos perfis estudados é responsável pela pedogênese de horizontes B com incremento de argila, característicos de Argissolos e Cambissolos. Os dados sugerem a identificação e interpretação de um sexto componente pedogenético definido como contexto geológico do entorno.
Relationships between microbial activity and soil physical and chemical properties in native and reforested Araucaria angustifolia forests in the state of São Paulo, Brazil
Authors: Pereira Jamil de Morais , Baretta Dilmar , Bini Daniel , Vasconcellos Rafael L. de F. , Cardoso Elke Jurandy Bran Nogueira
Published: July 2013

Araucaria angustifolia (Bert.) O. Kuntze is the main component of the Mixed Ombrophilous forest and, in the State of São Paulo, it is associated with a high diversity of soil organisms, essential for the maintenance of soil quality, making the conservation of this ecosystem a major and pressing challenge. The objective of this study was to identify the physical and chemical properties that are most closely correlated with dehydrogenase enzyme activity, basal respiration and microbial biomass under native (NF) and replanted (RF) Araucaria angustifolia forests in three regions of the state of São Paulo, in winter and summer. The main differentiating factors between the areas were also determined. Each forest was represented by three true replications; at each site, from around the araucaria trees, 15 soil samples (0-20 cm) were collected to evaluate the soil physical, chemical and microbiological properties. At the same points, forest litter was sampled to assess mass and chemical properties. The following microbiological properties were evaluated: microbial biomass carbon (MBC), basal respiration (CO2-C), metabolic quotient (Q: CO2), dehydrogenase enzyme activity (DHA) as well as the physical properties (moisture, bulk density, macroporosity and total porosity), soil chemical properties [pH, organic carbon (org-C), P, Ca, K, Mg, Al, H+Al], litter dry mass, and C, N and S contents. The data were subjected to analysis of variance (TWO-WAY: ANOVA). A Canonical Discriminant Analysis (CDA) and a Canonical Correlation Analysis (CCA) were also performed. In the soil under NF, the values of K, P, soil macroporosity, and litter dry mass were higher and Q: CO2 and DHA lower, regardless of the sampling period, and DHA was lower in winter. In the RF areas, the levels of moisture, porosity and Q: CO2 were higher in both sampling periods, and DHA was higher in winter. The MBC was only higher under NF in the summer, while the litter contents of C, N and S were greater in winter. In winter, CCA showed a high correlation of DHA with CO2-C, pH and H+Al, while in the summer org-C, moisture, Mg, pH and litter C were more associated with DHA and CO2-C. The CDA indicated H+Al, available P, total porosity, litter S content, and soil moisture as the most discriminating variables between NF and RF, but moisture was the most relevant, in both seasons and CO2-C only in winter. The combined analysis of CCA and CDA showed that the contribution of the microbiological variables to a differentiation of the areas was small at both samplings, which may indicate that the period after reforestation was long enough to allow an almost complete recovery of the microbial activity.
Estimation of soil moisture in the root-zone from remote sensing data
Authors: Bezerra Bergson Guedes , Santos Carlos Antonio Costa dos , Silva Bernardo Barbosa da , Perez-Marin Aldrin Martin , Bezerra Marcus Vinícius Cândido , Bezerra José Renato Cortez , Rao Tantravahi Venkata Ramana
Published: July 2013

Field-based soil moisture measurements are cumbersome. Thus, remote sensing techniques are needed because allows field and landscape-scale mapping of soil moisture depth-averaged through the root zone of existing vegetation. The objective of the study was to evaluate the accuracy of an empirical relationship to calculate soil moisture from remote sensing data of irrigated soils of the Apodi Plateau, in the Brazilian semiarid region. The empirical relationship had previously been tested for irrigated soils in Mexico, Egypt, and Pakistan, with promising results. In this study, the relationship was evaluated from experimental data collected from a cotton field. The experiment was carried out in an area of 5 ha with irrigated cotton. The energy balance and evaporative fraction (Λ) were measured by the Bowen ratio method. Soil moisture (θ) data were collected using a PR2 - Profile Probe (Delta-T Devices Ltd). The empirical relationship was tested using experimentally collected Λ and θ values and was applied using the Λ values obtained from the Surface Energy Balance Algorithm for Land (SEBAL) and three TM - Landsat 5 images. There was a close correlation between measured and estimated θ values (p<0.05, R² = 0.84) and there were no significant differences according to the Student t-test (p<0.01). The statistical analyses showed that the empirical relationship can be applied to estimate the root-zone soil moisture of irrigated soils, i.e. when the evaporative fraction is greater than 0.45.
Aplicação do método de mineralização de nitrogênio com lixiviação para solo tratado com lodo de esgoto e composto orgânico
Authors: Moretti Sarah Mello Leite , Bertoncini Edna Ivani , Abreu-Junior Cassio Hamilton
Published: July 2013

A determinação da taxa de mineralização de nitrogênio (N) em solos tratados com resíduos é fundamental para definir as doses a serem aplicadas, fornecendo N às plantas na época adequada, sem perdas do elemento por lixiviação. Inúmeros estudos em solos tratados com resíduos utilizam o teste de mineralização de N sem lixiviação e a caracterização das formas mineralizadas pelo método volumétrico. Em razão da deficiente repetibilidade do teste e da baixa sensibilidade do método de determinação observada em estudos com lodo de esgoto e composto orgânico, adotaram-se o método pouco difundido de mineralização de N com lixiviação e a especificação das formas minerais de N, por meio de métodos espectrofotométricos. O teste foi realizado em colunas de PVC, com 30 mm de diâmetro, preenchidas com terra retirada da camada 0,20 m de um solo classificado como Nitossolo Háplico, álico, argiloso, misturada às seguintes doses de resíduos, em Mg ha-1 (base úmida): lodo de esgoto - L1: 3,6; L2: 7,2; e L3: 14,4; e composto de lodo de esgoto e material vegetal triturado proveniente da poda de árvores urbanas - C1: 7,2; C2: 14,4; e C3: 28,8. As colunas foram incubadas e lixiviadas periodicamente com solução 0,01 mol L-1 KCl e as formas minerais de N determinadas colorimetricamente. Maiores taxas de mineralização ocorreram nas menores doses aplicadas de lodo e composto, evidenciando efeito priming, indesejado à fertilidade de solos sob condições tropicais. Menores taxas ocorreram nas doses L2 e C2, com valores próximos àqueles sugeridos pela legislação, não suprindo a demanda de N almejada, indicando possível necessidade de revisão na norma vigente. De modo geral, as taxas de mineralização foram maiores para o composto orgânico, enquanto a velocidade de degradação do composto orgânico foi menor que para o lodo, revelando maior distribuição da disponibilidade de N para a cultura ao longo do tempo. O método de mineralização com lixiviação e a determinação das formas de N-minerais por colorimetria evidenciaram-se rápidos e eficientes; estudos com solos e resíduos diversos podem validá-los para seu uso em rotina.
Spectroscopic quantification of soil phosphorus forms by 31p-nmr after nine years of organic or mineral fertilization
Authors: Gatiboni Luciano Colpo , Brunetto Gustavo , Rheinheimer Danilo dos Santos , Kaminski João , Pandolfo Carla Maria , Veiga Milton , Flores Alex Fabiani Claro , Lima Maria Angélica Silveira , Girotto Eduardo , Copetti André Carlos Cruz
Published: July 2013

Long-standing applications of mineral fertilizers or types of organic wastes such as manure can cause phosphorus (P) accumulation and changes in the accumulated P forms in the soil. The objective of this research was to evaluate the forms of P accumulated in soils treated with mineral fertilizer or different types of manure in a long-term experiment. Soil was sampled from the 0-5 cm layer of plots fertilized with five different nutrient sources for nine years: 1) control without fertilizer; 2) mineral fertilizer at recommended rates for local conditions; 3) 5 t ha-1 year-1 of moist poultry litter; 4) 60 m³ ha-1 year-1 of liquid cattle manure and 5) 40 m³ ha-1 year-1 of liquid swine manure. The 31P-NMR spectra of soil extracts detected the following P compounds: orthophosphate, pyrophosphate, inositol phosphate, glycerophosphate, and DNA. The use of organic or mineral fertilizer over nine years did not change the soil P forms but influenced their concentration. Fertilization with mineral or organic fertilizers stimulated P accumulation in inorganic forms. Highest inositol phosphate levels were observed after fertilization with any kind of manure and highest organic P concentration in glycerophosphate form in after mineral or no fertilization.
Doses de enxofre e tempo de incubação na dinâmica de formas de enxofre no solo
Authors: Uchôa Sandra Cátia Pereira , Víctor Hugo Alvarez V. , Freire Francisco Morel
Published: July 2013

A disponibilidade de enxofre (S) depende da dinâmica de suas formas no solo. Visando estudar o equilíbrio entre as reservas de S lábil e S não lábil, amostras de 10 solos foram incubadas com cinco doses de sulfato de cálcio (0, 20, 50, 80 e 120 mg dm-3 de S), durante 1, 8, 15, 30, 60 e 90 d. Para a determinação do S lábil, utilizou-se membrana de resina de troca aniônica em forma de lâmina. O S extraído com 48 h de agitação foi denominado de enxofre rapidamente lábil (SRL). O teor obtido com tempo de agitação superior a 48 h foi denominado de enxofre lentamente lábil e o não lábil (SLL+SNL), pela diferença entre o S do solo (extraído após calcinação) e SRL. A resistência que o solo oferece à passagem do S da reserva do SRL para a do SLL+SNL foi denominada de capacidade-tampão do S lábil (CTSL), sendo obtida pelo inverso do coeficiente angular das equações lineares do teor de SRL em função do teor de SLL+SNL. Constatou-se que tempo de incubação (reatividade) e as doses de S, na forma de sulfato de cálcio, influenciam a dinâmica do S entre as reservas de SRL e SLL+SNL. A CTSL é sensível às mudanças no equilíbrio entre as reservas de S no solo. O aumento da CTSL dos solos relacionou-se, principalmente, com a capacidade máxima de adsorção de sulfato, teor de carbono orgânico, goethita e gibbsita da fração argila dos solos estudados.
Effects of nickel and nitrogen soil fertilization on lettuce growth and urease activity
Authors: Oliveira Thomas Carlos , Fontes Renildes Lúcio Ferreira , Rezende Sebastião Tavares de , Víctor Hugo Alvarez V.
Published: July 2013

Nickel is a micronutrient involved in nitrogen metabolism and a constituent of the urease molecule. Plant growth and urease activity were evaluated in lettuce (Lactuca sativa L.) grown in soil-filled pots in a 2 x 8 factorial design with two nitrogen (N) sources and eight Ni rates, with five replications. Nitrogen was applied at 200 mg dm-3 (half the dose incorporated into the soil at seedling transplanting and half top-dressed later) using the sources NH4NO3 (AN) and CO(NH2)2 (Ur). The Ni treatments (0, 2, 4, 8, 12, 16, 24 and 32 mg dm-3) were applied as NiCl2. The shoot dry-matter yield, leaf urease activity, Ni levels in the lettuce leaves and Ni levels extracted from soil with Mehlich-3 (M-3) and DTPA were determined. In the plants supplied with AN, the shoot dry-matter yield was higher than in those supplied with Ur. There was no difference in shoot dry matter in response to soil-applied Ni. The leaf urease activity increased with Ni application, regardless of the N source. The extractions with M-3 and DTPA were efficient to evaluate Ni availability for lettuce in the Red-Yellow Latosol.
Mineralização de nitrogênio em latossolos adubados com resíduos orgânicos
Authors: Carneiro Waldete Japiassu de Oliveira , Silva Carlos Alberto , Muniz Joel Augusto , Savian Taciana Villela
Published: July 2013

A taxa de mineralização do nitrogênio (N) varia de um resíduo orgânico para outro, evidenciando-se dependente da sua composição química e interação do material orgânico com o solo. Este estudo foi realizado com o objetivo de avaliar a dinâmica de mineralização de N de resíduos orgânicos incubados em Latossolos. O experimento foi conduzido no período de julho de 2007 a abril de 2008, sendo incubadas amostras de estercos, lodos, compostos, substrato e turfa em areia lavada, Latossolo Vermelho-Amarelo (LVA) e Latossolo Vermelho distroférrico (LVdf), com 240 e 670 g kg-1 de argila, respectivamente. O N mineralizado foi avaliado medindo-se os teores de N-NH4+ e N-NO3- em lixiviados coletados aos 15, 30, 45, 60, 75, 90, 120, 150, 180, 210, 240 e 270 dias de incubação. A mineralização de N ocorreu a maiores taxas nos períodos iniciais de incubação. O N mineralizado (33 a 199,2 mg kg-1) após 270 dias de incubação é regulado pelos teores de N total e de carbono solúvel em água dos resíduos orgânicos. Independentemente do meio utilizado para incubação, os estercos de galinha e de codorna propiciaram os maiores teores de N mineralizado nos Latossolos. À exceção dos estercos de galinha e codorna, há imobilização líquida de N no LVA; mineralização líquida de N é verificada no LVdf, para todos os resíduos orgânicos. Em relação às formas de N disponibilizadas pelos resíduos, predomina o N-nitrato, sendo a proporção N-nítrico/N-amoniacal dependente da mistura solo-resíduo estudada.
Volatilização de amônia oriunda de ureia pastilhada com micronutrientes em ambiente controlado
Authors: Stafanato Juliano Bahiense , Goulart Rosimar de Souza , Zonta Everaldo , Lima Eduardo , Mazur Nelson , Pereira Carlos Guerra , Souza Heraldo Namorato de
Published: July 2013

Novas tecnologias com o intuito de minimizar as perdas de N-NH3 por volatilização devem ser desenvolvidas para aumentar a eficiência de uso do N-ureia. A incorporação de boro e cobre na ureia pode reduzir esses efeitos por meio da inibição da atividade da urease. O experimento foi conduzido em casa de vegetação, onde foram aplicados diferentes fertilizantes nitrogenados (ureia pastilhada com e sem boro e cobre, sulfato de amônio, ureia com inibidor da urease NBPT, ureia granulada e ureia revestida com boro e cobre) na superfície de um Planossolo Háplico contido em bandejas (0,1 m² de área e 10 cm de profundidade), em dose equivalente a 200 kg ha-1 de N. Foram avaliadas as perdas de N-NH3 por volatilização durante 18 dias, com o auxílio de um coletor semiaberto. A adição de cobre e boro no processo de pastilhamento da ureia reduziu as perdas de amônia por volatilização em até 54 %, quando comparado com a ureia granulada comercial, comprovando ser eficiente contra as perdas de N-NH3 por volatilização.