Causal Warrant for Realism about Particle Physics

While scientific realism generally assumes that successful scientific explanations yield information about reality, realists also have to admit that not all information acquired in this way is equally well warranted. Some versions of scientific realism do this by saying that explanatory posits with which we have established some kind of causal contact are better warranted than those that merely appear in theoretical hypotheses. I first explicate this distinction by considering some general criteria that permit us to distinguish causal warrant from theoretical warrant. I then apply these criteria to a specific case from particle physics, claiming that scientific realism has to incorporate the distinction between causal and theoretical warrant if it is to be an adequate stance in the philosophy of particle physics.

Amoebal pathogens as emerging causal agents of pneumonia.

Despite using modern microbiological diagnostic approaches, the aetiological agents of pneumonia remain unidentified in about 50% of cases. Some bacteria that grow poorly or not at all in axenic media used in routine clinical bacteriology laboratory but which can develop inside amoebae may be the agents of these lower respiratory tract infections (RTIs) of unexplained aetiology. Such amoebae-resisting bacteria, which coevolved with amoebae to resist their microbicidal machinery, may have developed virulence traits that help them survive within human macrophages, i.e. the first line of innate immune defence in the lung. We review here the current evidence for the emerging pathogenic role of various amoebae-resisting microorganisms as agents of RTIs in humans. Specifically, we discuss the emerging pathogenic roles of Legionella-like amoebal pathogens, novel Chlamydiae (Parachlamydia acanthamoebae, Simkania negevensis), waterborne mycobacteria and Bradyrhizobiaceae (Bosea and Afipia spp.).

Arabidopsis Basic Helix-Loop-Helix Transcription Factors MYC2, MYC3, and MYC4 Regulate Glucosinolate Biosynthesis, Insect Performance, and Feeding Behavior.

Arabidopsis thaliana plants fend off insect attack by constitutive and inducible production of toxic metabolites, such as glucosinolates (GSs). A triple mutant lacking MYC2, MYC3, and MYC4, three basic helix-loop-helix transcription factors that are known to additively control jasmonate-related defense responses, was shown to have a highly reduced expression of GS biosynthesis genes. The myc2 myc3 myc4 (myc234) triple mutant was almost completely devoid of GS and was extremely susceptible to the generalist herbivore Spodoptera littoralis. On the contrary, the specialist Pieris brassicae was unaffected by the presence of GS and preferred to feed on wild-type plants. In addition, lack of GS in myc234 drastically modified S. littoralis feeding behavior. Surprisingly, the expression of MYB factors known to regulate GS biosynthesis genes was not altered in myc234, suggesting that MYC2/MYC3/MYC4 are necessary for direct transcriptional activation of GS biosynthesis genes. To support this, chromatin immunoprecipitation analysis showed that MYC2 binds directly to the promoter of several GS biosynthesis genes in vivo. Furthermore, yeast two-hybrid and pull-down experiments indicated that MYC2/MYC3/MYC4 interact directly with GS-related MYBs. This specific MYC-MYB interaction plays a crucial role in the regulation of defense secondary metabolite production and underlines the importance of GS in shaping plant interactions with adapted and nonadapted herbivores.

Improving Dynamic Characteristics of Open-loop Controlled Log Crane

The improvement of the dynamics of flexible manipulators like log cranes often requires advanced control methods. This thesis discusses the vibration problems in the cranes used in commercial forestry machines. Two control methods, adaptive filtering and semi-active damping, are presented. The adaptive filter uses a part of the lowest natural frequency of the crane as a filtering frequency. The payload estimation algorithm, filtering of control signal and algorithm for calculation of the lowest natural frequency of the crane are presented. The semi-active damping method is basedon pressure feedback. The pressure vibration, scaled with suitable gain, is added to the control signal of the valve of the lift cylinder to suppress vibrations. The adaptive filter cuts off high frequency impulses coming from the operatorand semi-active damping suppresses the crane?s oscillation, which is often caused by some external disturbance. In field tests performed on the crane, a correctly tuned (25 % tuning) adaptive filter reduced pressure vibration by 14-17 % and semi-active damping correspondingly by 21-43%. Applying of these methods require auxiliary transducers, installed in specific points in the crane, and electronically controlled directional control valves.

Utilização de marcador molecular SCAR na identificação de Fusarium subglutinans, agente causal da malformação da mangueira

O gênero Fusarium é responsável por doenças em diversas plantas economicamente importantes. Entre estas doenças, destaca-se a malformação da mangueira, causada pelo fungo Fusarium subglutinans. O objetivo deste trabalho foi desenvolver oligonucleotídeos iniciadores para reação em cadeia da polimerase (PCR), específicos para o fungo F. subglutinans da mangueira. A amplificação de DNA de oito Fusarium spp. de diferentes hospedeiros, usando o oligonucleotídeo randômico UBC-41 (TTAACCGGGG), produziu um fragmento de aproximadamente 1.300 pb somente para o fungo da mangueira. Tendo em vista que padrões de bandeamento por RAPD não são considerados confiáveis devido à baixa reprodutibilidade dos resultados, o fragmento diferencial foi eluído do gel de agarose, purificado, clonado e seqüenciado. As seqüências nucleotídicas foram utilizadas para identificar e sintetizar quatro pares de oligonucleotídeos específicos, denominados Fs 5, Fs 13, Fs 14 e Fs 15. DNAs de Fusarium spp. de outros hospedeiros (alho, amendoim, cana-de-açúcar, ciclâmen, ervilha, melão e trigo), da planta de mangueira cv. Tommy Atkins sadia e de outros cinco isolados de F. subglutinans de mangueira sintomática, foram submetidos à amplificação com os pares de oligonucleotídeos. Fragmentos amplificados foram visualizados somente para F. subglutinans de mangueira, demonstrando assim a especificidade dos oligonucleotídeos SCAR desenhados.

Efeito do extrato de alho na quebra de dormência de gemas de videiras e no controle in vitro do agente causal da antracnose (Elsinoe ampelina Shear)

Considerando a redução ou eliminação do uso de substâncias sintéticas que preconizam os sistemas sustentáveis de produção de frutas, este trabalho teve como objetivo a busca de novas alternativas para a quebra de dormência e o controle de doenças em videiras. Estacas de videira contendo uma gema foram pulverizadas com os seguintes tratamentos: 1) testemunha; 2) OV (óleo vegetal) 1%; 3) extrato de alho (EA) 3%; 4) EA 3% + OV 1%. Posteriormente, as estacas foram mantidas em câmara de crescimento (25±2.5ºC) por 56 dias. O único tratamento que estimulou a brotação das estacas de videira cv. Isabel Precoce foi o EA 3% + OV 1%, que atingiu 35% de brotação, diferindo estatisticamente dos tratamentos- testemunha (12,5%), OV 1% (17,5%) e EA 3% (15,0%). Provavelmente, o estádio de endodormência profunda das gemas, após apenas 90 horas de frio ( < 7,0ºC), impediu melhores resultados dos tratamentos para quebra de dormência. Três experimentos, foram conduzidos in vitro, com diferentes doses de extrato de alho, com o objetivo de avaliar o controle do fungo Elsinoe ampelina. Em todos os experimentos, houve efeito quadrático no crescimento micelial, sem ter havido diferenças entre os tratamentos com extrato de alho, evidenciando o seu efeito fungicida, mesmo na dose mais baixa de EA (0,0615%).

Controle alternativo de Colletotrichum acutatum agente causal da queda prematura dos frutos cítricos

A queda prematura dos frutos cítricos (QPFC), causada por Colletotrichum acutatum, dados os grandes prejuízos que têm causado aos produtores, constitui-se numa doença de grande importância econômica. O controle da doença é feito predominantemente mediante uso de fungicidas, que eleva o custo de produção e afeta negativamente o meio ambiente. Diante disso, este trabalho teve por objetivo buscar um método alternativo de controle da QPFC, mediante o uso de agentes de biocontrole ou de biofertilizantes. Diferentes concentrações de biofertilizantes (originários de duas fontes distintas e denominados de Bio1 e Bio 2); três isolados de Bacillus subtilis (ACB-69; 72 e 77) e três isolados de Trichoderma spp. (ACB-14; 37 e 39) foram testados, isoladamente ou em combinação, sob condições de laboratório, quanto à capacidade inibitória da germinação de conídios de C. acutatum. Estudaram-se, ainda, a produção de metabólitos termoestáveis por B. subtilis e o efeito sobre a germinação do patógeno. Quinze isolados de B. subtilis foram testados quanto à capacidade de prevenir a infecção por C. acutatum em flores destacadas de lima- ácida 'Tahiti' e, no campo, foram instalados dois experimentos, visando a testar ACBs e biofertilizantes no controle da doença. Verificou-se que o isolado ACB-72 (B. subtilis) e ACB-37 (T. pseudokoningii) foram os que mais inibiram a germinação do patógeno. Quanto à produção de metabólitos termoestáveis, ACB-69 e 77 foram os mais eficientes em produzir substâncias antifúngicas, e em quantidades suficientes para inibirem a germinação do patógeno. A mistura dos quatro isolados de Bacillus (ACBs: 69; 72; 77 e AP3) foi o que apresentou maior porcentagem de inibição (73%). Os biofertilizantes (Bio1 e Bio2), em concentrações acima de 10% e, quando em associação com isolados de Trichoderma spp., promoveram maiores inibições na germinação de C. acutatum. Em testes com flores destacadas, verificou-se que, onde foram aplicados os ACBs 69; 76; 74 e 77, as porcentagens de pétalas sem sintomas de infecção por C. acutatum foram de 83; 92; 92 e 97%, respectivamente. Mediante avaliações a campo, verificou-se a potencialidade de B. subtilis e de biofertilizantes em controlar a doença.

Avaliação de genótipos tetraploides de bananeira cultivados em área infestada pelo agente causal do mal-do-Panamá

O mal-do-Panamá é uma doença que causa grandes prejuízos à bananicultura no Brasil, uma vez que as principais cultivares em uso são suscetíveis ao Fusarium. Este trabalho teve como objetivos avaliar características agronômicas e resistência ao mal-do-Panamá de híbridos tetraploides de bananeira. O experimento foi conduzido no campo experimental da Embrapa Mandioca e Fruticultura Tropical, em delineamento casualizado, com 14 tratamentos e 10 repetições, nos anos de 2000 e 2001. Foram avaliados 14 tetraploides (FHIA-03, PV03-44, PC42-01, PV42-53, PV42-68, PV42-81, PV42-85, PV42-129, PV42-142, PV42-143, SH3640, ST12-31, ST42-08 e YB42-21) e a cultivar Maçã, usada como testemunha. Avaliaram-se as características altura da planta (m) e diâmetro do pseudocaule (cm) a 30 cm do solo, peso da massa do cacho (kg), penca (kg) e fruto (g), número de pencas por cacho, de frutos por penca e de dias do florescimento à colheita, e a incidência do mal-do-Panamá. As médias dos genótipos foram agrupadas pelo teste de Scott e Knott, a 5% de probabilidade. Observa-se uma ampla variação genética nos caracteres avaliados. Os genótipos FHIA 03, ST12-31, SH3640, PV42-142, PV42-53 e PV42-68apresentam boas características agronômicas e resistência ao mal-do-Panamá.

The role of causal links in performance measurement models

Abstract Purpose: Several well-known managerial accounting performance measurement models rely on causal assumptions. Whilst users of the models express satisfaction and link them with improved organizational performance, academic research, of the realworld applications, shows few reliable statistical associations. This paper provides a discussion on the"problematic" of causality in a performance measurement setting. Design/methodology/approach: This is a conceptual study based on an analysis and synthesis of the literature from managerial accounting, organizational theory, strategic management and social scientific causal modelling. Findings: The analysis indicates that dynamic, complex and uncertain environments may challenge any reliance upon valid causal models. Due to cognitive limitations and judgmental biases, managers may fail to trace correct cause-and-effect understanding of the value creation in their organizations. However, even lacking this validity, causal models can support strategic learning and perform as organizational guides if they are able to mobilize managerial action. Research limitations/implications: Future research should highlight the characteristics necessary for elaboration of convincing and appealing causal models and the social process of their construction. Practical implications: Managers of organizations using causal models should be clear on the purposes of their particular models and their limitations. In particular, difficulties are observed in specifying detailed cause and effect relations and their potential for communicating and directing attention. They should therefore construct their models to suit the particular purpose envisaged. Originality/value: This paper provides an interdisciplinary and holistic view on the issue of causality in managerial accounting models.

Population Size and Civil Conflict Risk: Is There A Causal Link?

[spa] La estimación del impacto del tamaño de la populación sobre la probabilidad de conflicto civil se complica por el sesgo de endogeneidad y las variables omitidas. Este artículo trata el problema de causalidad utilizando métodos de variables instrumentales en un panel de 37 países del África Sub-sahariana en el período 1981-2004. Encontramos que un aumento de la población en un 1% aumenta la probabilidad de conflicto civil por un 5.2%.

Heavier smoking may lead to a relative increase in waist circumference: evidence for a causal relationship from a Mendelian randomisation meta-analysis. The CARTA consortium.

OBJECTIVES: To investigate, using a Mendelian randomisation approach, whether heavier smoking is associated with a range of regional adiposity phenotypes, in particular those related to abdominal adiposity. DESIGN: Mendelian randomisation meta-analyses using a genetic variant (rs16969968/rs1051730 in the CHRNA5-CHRNA3-CHRNB4 gene region) as a proxy for smoking heaviness, of the associations of smoking heaviness with a range of adiposity phenotypes. PARTICIPANTS: 148 731 current, former and never-smokers of European ancestry aged ≥16 years from 29 studies in the consortium for Causal Analysis Research in Tobacco and Alcohol (CARTA). PRIMARY OUTCOME MEASURES: Waist and hip circumferences, and waist-hip ratio. RESULTS: The data included up to 66 809 never-smokers, 43 009 former smokers and 38 913 current daily cigarette smokers. Among current smokers, for each extra minor allele, the geometric mean was lower for waist circumference by -0.40% (95% CI -0.57% to -0.22%), with effects on hip circumference, waist-hip ratio and body mass index (BMI) being -0.31% (95% CI -0.42% to -0.19), -0.08% (-0.19% to 0.03%) and -0.74% (-0.96% to -0.51%), respectively. In contrast, among never-smokers, these effects were higher by 0.23% (0.09% to 0.36%), 0.17% (0.08% to 0.26%), 0.07% (-0.01% to 0.15%) and 0.35% (0.18% to 0.52%), respectively. When adjusting the three central adiposity measures for BMI, the effects among current smokers changed direction and were higher by 0.14% (0.05% to 0.22%) for waist circumference, 0.02% (-0.05% to 0.08%) for hip circumference and 0.10% (0.02% to 0.19%) for waist-hip ratio, for each extra minor allele. CONCLUSIONS: For a given BMI, a gene variant associated with increased cigarette consumption was associated with increased waist circumference. Smoking in an effort to control weight may lead to accumulation of central adiposity.

Protein loop compaction and the origin of the effect of arginine and glutamic acid mixtures on solubility, stability and transient oligomerization of proteins

Addition of a 50 mM mixture of l-arginine and l-glutamic acid (RE) is extensively used to improve protein solubility and stability, although the origin of the effect is not well understood. We present Small Angle X-ray Scattering (SAXS) and Nuclear Magnetic Resonance (NMR) results showing that RE induces protein compaction by collapsing flexible loops on the protein core. This is suggested to be a general mechanism preventing aggregation and improving resistance to proteases and to originate from the polyelectrolyte nature of RE. Molecular polyelectrolyte mixtures are expected to display long range correlation effects according to dressed interaction site theory. We hypothesize that perturbation of the RE solution by dissolved proteins is proportional to the volume occupied by the protein. As a consequence, loop collapse, minimizing the effective protein volume, is favored in the presence of RE.