Effects of high-order space harmonics on the operation of five-phase induction machines under unbalance.

The paper addresses the effects of high-order space harmonics on the steady-state performance of five-phase induction machines operating under unbalance. We show that the airgap harmonic fields with orders higher than three, although usually disregarded, can produce a significant increase in the torque pulsation and in the Joule losses. We propose a model based on symmetric components which is used to demonstrate that the field produced by each rotor harmonic current is related to two stator sequence currents. Further, the proposed model allows determining additional losses and harmonic torques produced by airgap harmonic fields with orders higher than three, which up to now have not been addressed elsewhere. As a case study, we applied the model to two five-phase induction machines with different designs and assessed the influence of high space harmonics under operation at steady state with one open phase in the stator. The model has been validated by comparing analytical results with results obtained through finite element analysis. Finally, the model validation was also based on experimental results obtained from tests with two prototypes under many different conditions.

Induction distribution of five-phase induction machines under open-phase fault.

The main objective of the paper is to determine the induction distribution of five-phase induction machines operating under unbalanced steady state, focusing on the operation with two opened stator phases. Firstly, we present an analytical model based on symmetric components which includes the third harmonic component of the airgap induction. The model is then used to determine the induction distribution in the airgap and also in the main iron parts, i.e. cores and teeth of the stator and rotor parts. The analytical model is thoroughly validated through two-dimensional Finite Element Analysis (FEA) and using extensive experimental data obtained from tests taken on a prototype machine of 5.5 kW; experimental data, as well results from FEA, showed a close agreement with theoretical data, which confirms the accuracy of the proposed model. The results indicate that when two phases are opened and with no control strategy to compensate the fault, the induction distributions can change significantly, predominantly in the stator and rotor teeth, as a result of additional induction harmonic components. These changes in the field distribution of stator and rotor teeth, in turn, can increase the associated magnetic losses as they are no longer evenly distributed among the teeth, thus potentially creating hot spots inside the machine. The model proposed can, therefore, serve as a basis to assess the overall magnetic losses and the load capacity under fault, given that the field distribution, as well as its associated effects, is essential to establish the machine capacity under unbalance.

Performance estimation of three-phase induction motors from no-load startup test without speed acquisition.

This paper presents a simple method to estimate the steady-state performance of three-phase induction motors using only measurements of stator voltages and currents, acquired during a no-load startup test and without speed acquisition. The procedure consists of two steps: (a) firstly, the parameters of the single-cage model are estimated while considering the rotor resistance and the leakage inductances variable with the slip; and (b) secondly, the steady-state performance is estimated from the equivalent circuit using the estimated parameters. The proposed method is experimentally validated through tests involving 229 medium-power motors with power ranging from 22 to 90 kW; the estimated performance is then compared with measurements obtained through standardized laboratory tests. In addition, we also estimated the performance using a known double-cage model with constant parameters and compare the results with those obtained with the proposed model. We demonstrate that the proposed method provides accurate estimates for the main performance characteristics, such as efficiency and rated torque, which usually cannot be correctly assessed without direct measurements. The method makes it possible to estimate the performance of medium-power induction motors within acceptable accuracy through quick and low-cost tests requiring few sensors, making it a potential substitute for expensive and labor-intensive laboratory tests.

A new high-altitude species of centipede from the Andes of Ecuador (Chilopoda, Geophilomorpha, Schendylidae).

Pectiniunguis aequatorialis sp. nov. (Chilopoda: Geophilomorpha: Schendylidae) is described and illustrated on the basis of specimens collected in the Cayambe-Coca Ecological Reserve in the High Andes of Ecuador. The new species is characterized by having ventral pore-fields on the anterior region of the trunk only, a trait that is shared by a single Neotropical congener: Pectiniunguis ascendens Pereira, Minelli Barbieri, 1994 to which it is similar and is compared taxonomically. This is only the second report of a species of the genus Pectiniunguis Bollman, 1889 from mainland Ecuador. The other taxon is Pectiniunguis roigi Pereira, Foddai Minelli, 2001, so far only known from the type locality, Limoncocha (Sucumbíos Province), and herein reported for the first time from Parque Nacional Sumaco Napo-Galeras (Napo Province).

Long 3'UTR of Nurr1 mRNAs is targeted by miRNAs in mesencephalic dopamine neurons.

The development of mesencephalic dopamine neurons and their survival later in life requires the continuous presence of the transcription factor Nurr1 (NR4A2). Nurr1 belongs to the nuclear receptors superfamily. However, it is an orphan member that does not require a ligand to regulate the transcription of its target genes. Therefore, controlling the expression of Nurr1 is an important manner to control its function. Several reports have shown that microRNAs (miRNAs) regulate Nurr1 expression. However, Nurr1 has several splicing variants, posing the question what variants are subjected to miRNA regulation. In this work, we identified a long 3'UTR variant of rat Nurr1 mRNA. We used bioinformatics analysis to identify miRNAs with the potential to regulate Nurr1 expression. Reporter assays performed with the luciferase gene fused to the short (658 bp) or long (1,339 bp) 3'UTR of rat Nurr1 mRNAs, showed that miR-93, miR-204 and miR-302d selectively regulate the mRNA with the longest 3'UTR. We found that the longest variant of Nurr1 mRNA expresses in the rat mesencephalon as assessed by PCR. The transfection of rat mesencephalic neurons with mixed miR-93, miR-204 and miR-302d resulted in a significant reduction of Nurr1 protein levels. In conclusion, Nurr1 mRNA variant with the longest 3'UTR undergoes a specific regulation by miRNAs. It is discussed the importance of fine-tuning Nurr1 protein levels in mesencephalic dopamine neurons.

Plateurytion roigi sp. nov., a new geophilid centipede (Myriapoda: Chilopoda: Geophilomorpha) from Southern Chile.

Plateurytion roigi sp. nov. (Chilopoda: Geophilomorpha: Geophilidae) is fully described and illustrated from the holotype female from southern Chile (Region X (de Los Lagos region): Palena province). The new species seems particularly similar to P. gracilis (Gervais, 1849) (from Chile and Argentina), to which it is accordingly compared in detail for a confident identification. This is the sixth report of a species of the genus Plateurytion Attems, 1909, from Chile. The others are P. gracilis (Gervais, 1849); P. metopias (Attems, 1903); P. michaelseni (Attems, 1903); P. mundus (Chamberlin, 1955); and P. zapallar (Chamberlin, 1955). New geographic records are given for Plateurytion mauryi Pereira, 2008, which is reported for the first time from San Juan province, up to now only known from the type locality (in Mendoza province), central-western Argentina. Plateurytion yungarum (Pereira, 2005), is reported from the montane cloud forest altitudinal level of the Yungas forest of northwestern Argentina, until now it has only been recorded from the (lowest) montane forest altitudinal level of the Yungas.

A further contribution to the knowledge of two inadequately known species of geophilid centipedes from the Andes of South-Central Chile, currently assigned to the genus Plateurytion Attems, 1909 (Chilopoda: Geophilomorpha).

Two poorly known species of geophilid centipedes from the Andes of South-Central Chile, i.e., Plateurytion mundus (Chamberlin, 1955) and Plateurytion zapallar (Chamberlin, 1955) (Myriapoda: Chilopoda: Geophilomorpha), are herein redescribed and illustrated after type specimens of both taxa and new material of the latter, rectifying the condition of the coxosternites of the second maxillae, which are medially joined through a narrow, hyaline and non-areolate membranous isthmus only (instead of "broadly fused as in Pachymerium", as stated by Chamberlin), this being consistent with the current generic assignment of these species under Plateurytion Attems, 1909. New data on many morphological features of specific value, until now unknown, are also given for both taxa. Plateurytion zapallar is reported for the first time from Coquimbo region, 11 Km N of Los Vilos (Elqui province), Valparaíso region, Quebrada Huaquén, Pichicuy (Petorca province), La Campana National Park (Quillota province), and Quebrada el Tigre, Cachagua (Valparíso province). A key for identification of the South American species currently included in Plateurytion is given.

A new schendylid centipede (Myriapoda: Chilopoda: Geophilomorpha) from the Bolivian Amazon Forest.

Schendylops grismadoi sp. nov., a new schendylid centipede (Chilopoda: Geophilomorpha) from the Amazon forest of east-central Bolivia (Santa Cruz Department, Guarayos Province) is described and illustrated based on the holotype female. The new species is characterized by having an uninterrupted series of ventral pore-fields, from first to penultimate sternite inclusive (undivided on anterior and posterior sternites, divided in two subsymmetrical areas on the intermediate); these combined traits being shared by five other Neotropical species currently included in the genus Schendylops Cook, 1899, i.e., S. tropicus (Brölemann & Ribaut, 1911) (from French Guiana), S. inquilinus Pereira, Uliana & Minelli, 2007 (from Brazil), S. coscaroni (Pereira & Minelli, 2006) (from Brazil), S. demelloi (Verhoeff, 1938) (from Brazil), and S. parahybae (Chamberlin, 1914) (from Brazil). The new taxon is differentiated from all aforementioned species by having the anterior margin of cephalic plate conspicuously notched in the middle, dentate lamellae of mandibles divided in two blocks, and basal internal edge of forcipular tarsungulum with a small pigmented tooth; it is included in a key which will enable the identification of all known Neotropical members having sternal pore-fields all along the trunk (including those with an interrupted series on some mid-body sternites). S. grismadoi is only the fifth species of geophilomorph centipede recorded from Bolivia.

First report of geophilid centipedes of the genus Ribautia (Myriapoda: Chilopoda: Geophilomorpha) from the Atlantic Forest biome, with description of a new miniature species from Misiones Province, Northeastern Argentina.

Ribautia paranaensis sp. nov. a new miniature species of geophilid centipede from the Upper Paraná Atlantic Forest (the westernmost of the fifteen ecoregions comprising the Atlantic Forest biome sensu Di Bitetti et al. 2003), is herein described and illustrated. The new species is characterized by having the coxal organs grouped in clusters (one of these in each coxopleuron of the ultimate leg-bearing segment) and a claw-like pretarsus in the ultimate legs; these traits being shared by three other Neotropical members of the genus, i.e., R. combinata Pereira, Uliana & Minelli, 2006 (from the Amazonian rainforest of Peru), R. jakulicai Pereira, 2007 (from the Yungas rainforest of Northwestern Argentina), and R. lewisi Pereira, 2013 (collected in a gallery forest in the Mesopotamian region, Northeastern Argentina). R. paranaensis sp. nov. represents the first report of Ribautia Brölemann, 1909 in the entire Atlantic Forest biome, and the third confirmed record of the taxon from Argentina.

PIASγ enhanced SUMO-2 modification of Nurr1 activation-function-1 domain limits Nurr1 transcriptional synergy.

Nurr1 (NR4A2) is a transcription factor that belongs to the orphan NR4A group of the nuclear receptor superfamily. Nurr1 plays key roles in the origin and maintenance of midbrain dopamine neurons, and peripheral inflammatory processes. PIASγ, a SUMO-E3 ligase, represses Nurr1 transcriptional activity. We report that Nurr1 is SUMOylated by SUMO-2 in the lysine 91 located in the transcriptional activation function 1 domain of Nurr1. Nurr1 SUMOylation by SUMO-2 is markedly facilitated by overexpressing wild type PIASγ, but not by a mutant form of PIASγ lacking its first LXXLL motif (PIASγmut1). This PIASγmut1 is also unable to interact with Nurr1 and to repress Nurr1 transcriptional activity. Interestingly, the mutant PIASγC342A that lacks SUMO ligase activity is still able to significantly repress Nurr1-dependent transcriptional activity, but not to enhance Nurr1 SUMOylation. A SUMOylation-deficient Nurr1 mutant displays higher transcriptional activity than the wild type Nurr1 only in promoters harboring more than one Nurr1 response element. Furthermore, lysine 91, the major target of Nurr1 SUMOylation is contained in a canonical synergy control motif, indicating that SUMO-2 posttranslational modification of Nurr1 regulates its transcriptional synergy in complex promoters. In conclusion, PIASγ can exert two types of negative regulations over Nurr1. On one hand, PIASγ limits Nurr1 transactivation in complex promoters by SUMOylating its lysine 91. On the other hand, PIASγ fully represses Nurr1 transactivation through a direct interaction, independently of its E3-ligase activity.

Further contribution to the knowledge of Ityphilus calinus Chamberlin, 1957, a poorly known ballophilid centipede from Colombia, with description of Ityphilus bonatoi, a new diminutive geophilomorph species from Brazil (Myriapoda: Chilopoda, Geophilomorpha).

Ityphilus calinus Chamberlin, 1957 (Chilopoda: Geophilomorpha, Ballophilidae), a poorly known centipede from Cauca Valley, Colombia, is herein redescribed and illustrated after the male holotype, revealing the condition of the forcipular tarsungulum (which is completely smooth), also giving new data on many other morphological features of specific value until now unknown. A new diminutive species named Ityphilus bonatoi sp. nov. is herein proposed after the holotype female from Rio de Janeiro State, Brazil. The new species is characterized by having the internal edge of the forcipular tarsungulum serrate; among the other Neotropical members of the genus having the same trait, it only shares with I. donatellae Pereira, 2012 (from Central Amazon) a very small body size and a low number of leg-bearing segments. The new species represents the first record of the genus Ityphilus from the Atlantic Rainforest biome, and the southernmost representative of the genus in the Continent. A key for identification of the Neotropical species currently included in Ityphilus is also given.

Ribautia lewisi sp. nov., a new centipede from Argentina with unusual tentorial process (Chilopoda: Geophilomorpha, Geophilidae).

Ribautia lewisi sp. nov. (Chilopoda: Geophilomorpha, Geophilidae) is herein described and illustrated after the holotype (male), paratypes (males and females), and additional non type specimens from Northeastern Argentina (Mesopotamian region). The new species is characterized by having a cluster of coxal organs in each coxopleuron of the ultimate leg-bearing segment and a claw-like pretarsus in the ultimate legs, bearing a very unusual feature, in that the internal limbs of tentorium have a conspicuous tooth-shaped sclerotized process directed inward. R. lewisi sp. nov. is only the second confirmed record of the genus Ribautia from Argentina, the other being R. jakulicai Pereira, 2007 from Northwestern region of the country (Yungas biogeographical province).

Effects of ambient levels of air pollution generated by traffic on birth and placental weights in mice.

OBJECTIVE: To examine whether there is an association between fetal and/or placental weight and exposure to ambient levels of air pollution in mice. DESIGN: Chronic experiments on mice that were exposed to polluted vs. clean air. SETTING: Environmental exposure to atmospheric pollution. ANIMAL(S): Female Swiss mice (n = 70) were maintained at different stages of gestation in an exposure chamber located at an intersection with heavy traffic in a major city in Brazil. Control mice were maintained in a similar chamber, located adjacent to the exposure chamber but equipped with filters for particles and reactive gases. INTERVENTION(S): Animals were divided into six groups as follows: no exposure, exposure to a polluted chamber throughout gestation, exposure to a polluted chamber during the 1st week of pregnancy, exposure to a polluted chamber during the 2nd and 3rd weeks, exposure to a polluted chamber during the 1st and 2nd week, and exposure to a polluted chamber during the 3rd week. MAIN OUTCOME MEASURE(S): At the end of the gestational period, the determination of fetal and placental weight was performed after cesarean section. RESULT(S): Exposure to air pollution during the 1st week of pregnancy promoted a significant reduction in fetal weight. Mice exposed to polluted air, in any phase of gestation, presented with lower placental weight in comparison to mice maintained in clean chambers. CONCLUSION(S): Exposure to ambient levels of traffic pollution at early phases of gestation is a determinant for decreased final fetal weight. Placental weight is reduced with exposure to air pollution at any phase of gestation.

Environmental epidemiology applied to urban atmospheric pollution: a contribution from the Experimental Air Pollution Laboratory (LPAE)

A investigaçäo sobre os efeitos da exposiçäo humana à poluiçäo ambiental iniciou de maneira sistemática, com abordagem científica, apenas no século XX, como conseqüência de uma série de acidentes ambientais percebidos por um significativo aumento na mortalidade e com a realizaçäo de estudos epidemiológicos observacionais e toxicológicos em animais. Tais estudos têm se concentrado nos países considerados desenvolvidos. Relata a experiência do Laboratório de Poluiçäo Atmosférica Experimental (LPAE), da Faculdade de Medicina da Universidade de Säo Paulo, no estudo dos mecanismos fisiopatológicos do sistema respiratório em face da exposiçäo aos poluentes, utilizando abordagens experimentais e toxicológicas, complementadas com estudos epidemiológicos observacionais na cidade de Säo Paulo. Descreve como esses estudos se inserem no panorama mundial, convergindo para um consenso de que a poluiçäo do ar é prejudicial à saúde pública, e que esses efeitos säo observados inclusive em concentraçöes de poluentes abaixo dos limites estabelecidos pela legislaçäo ambiental em vigor, fornecendo dados valiosos para subsidiar a tomada de decisöes políticas e econômicas para a melhoria do meio ambiente.