Algebroid Yang-Mills Theories

A framework for constructing new kinds of gauge theories is suggested. Essentially it consists in replacing Lie algebras by Lie or Courant algebroids. Besides presenting novel topological theories defined in arbitrary spacetime dimensions, we show that equipping Lie algebroids E with a fiber metric having sufficiently many E-Killing vectors leads to an astonishingly mild deformation of ordinary Yang-Mills theories: Additional fields turn out to carry no propagating modes. Instead they serve as moduli parameters gluing together in part different Yang-Mills theories. This leads to a symmetry enhancement at critical points of these fields, as is also typical for String effective field theories.Comment: 4 pages; v3: Minor rewording of v1, version to appear in Phys. Rev. Let

Nesting patterns of bees (Apidae) in brick walls in southern Brazil

Aiming to verify the nesting pattern of solitary bee species, a study was performed (October 2012 to March 2013) in Joinville, SC, southern Brazil, along a brick wall. There were found the following species Melitoma segmentaria (Emphorini), Caenohalictus incertus (Halictini)and Leiopodus lacertinus (Protepeolini). 147 nests showed activity in the sampling period (118 of C. incertus, 29 of M. segmentaria), 98% located in the masonry. For M. segmentaria, 29 active nests were observed (density of 4.53/ m2), with an average distance of 12.22 cmbetween them, 17 nests between the ground and 90 cm high, istributed in aggregated form (R = 0.004, p <0.02). The nests opening measured on average 0.9 cm in diameter (n =29), two of them with a mud tower entrance 0.6 cm high, with a smooth inner wall and a outer, rough. For C. incertus, 118 active nests were observed (density of 18.43/ m2), with a mean distance of 8.18 cm from each other, 98 nests between the ground and 70 cm high, distributed in aggregated form (R = 0.066, p <0.09). Individuals of L. lacertinus were noticed in all observations days, at the entrance of nests of M. segmentaria. Anthrax cf. virgo emerged from M. segmentaria nests

Minifúndios e "inquilinato" no estuário amazônico: o caso do projeto agroextrativista Nossa Senhora do Perpétuo Socorro, Ilha Quianduba, município de Abaetetuba, Pará.

As estratégias de sobrevivência dos minifúndios de várzea do estuário do Rio Amazonas, tendo como referência a Ilha Quianduba, situada no Município de Abaetetuba, no Estado do Pará, é a razão deste estudo. O espaço geográfico selecionado foi objeto da ação estatal, quando o Governo Federal, no ano de 2006, interveio na região, por intermédio do Instituto Nacional de Colonização e Reforma Agrária e da Gerência Regional do Patrimônio da União, e viabilizou a transformação de um imóvel rural com área de 2.810,9 hectares, sob jurisdição da União, num Projeto de Assentamento Agroextrativista, considerado uma Unidade de Conservação de Uso Sustentável, na modalidade Reserva Extrativista, por equiparação. As informações sobre as famílias, em número de 600, foram coletadas por intermédio de entrevistas de campo que, depois de tabuladas e confrontadas com a realidade, permitiram fazer inferências sobre as comunidades que integram o projeto, gênero, grau de parentesco, moradia, tempo de ocupação da área, hierarquia da ocupação, tamanho das posses, faixa etária dos componentes das famílias, renda familiar, educação, saúde, saneamento, associativismo, lazer, cultura, extrativismo do açaí, pesca do camarão, olarias, caça, pesca e utilização de crédito rural. As conclusões obtidas estão relacionadas com o reconhecimento de direitos dos moradores que passaram a integrar a base de dados do INCRA, sendo sujeitos de direitos e obrigações, quebrando o paradigma do sistema de inquilinato constituído até então. O emprego de políticas compensatórias pontuais sem considerar uma visão de médio prazo é incapaz de produzir melhoria nas condições de vida dos ribeirinhos, pois a ausência de assistência técnica, crédito rural, infraestrutura e documentação da terra é constatação cabal dessa assertiva. Caso os recursos naturais da Ilha continuem a ser explorados na atual escala, sem que haja atendimento às disposições reguladoras de seu uso, poderão levar a uma situação definida por Hardin (1968) como a tragédia dos comuns. A observação da relação simbiótica do Homem com a natureza representa a visão mais otimista desta proposta

Influence of opposition team formation on physical and skill-related performance in a professional soccer team

This study examined the influence of opposition team formation on physical and skill-related performance in a professional soccer team. Performance in forty-five French League 1 matches played over three competitive seasons (2007-08, 2008-09, and 2009-10) was analysed using multi-camera computerised tracking. Players (n=21) in the reference team (using a 4-3-3/4-5-1 formation) were analysed in matches against three opposition team formations: 4-4-2 (11 games), 4-3-3/4-5-1 (16 games) and 4-2-3-1 (18 games). Performance was compared for defending and midfield units as a whole and individually across four positions: fullbacks, central-defenders and central- and wide-midfielders. Collectively, players covered a greater total distance (p<0.05) and distance in low/moderate-intensity running (0-14.3km/h) (p<0.05) in matches against a 4-2-3-1 compared to a 4-4-2 formation. Distance covered in high-intensity (14.4-19.7km/h) and very high-intensity running (≥19.8km/h) was not affected by opposition formation. In contrast, players covered more distance in total high-intensity performance (≥14.4km/h) when the reference team was in possession against a 4-4-2 compared to a 4-2-3-1 formation (p<0.05) while more distance was run at these speeds when the reference team was out of possession against a 4-2-3-1 (p<0.01) and a 4-3-3 (p<0.05) compared to a 4-4-2 formation. Players ran less distance at low/moderate intensities in the second- versus first-half of matches against all three formations (p<0.01 to p<0.05) whereas total distance and high-intensity performance was unaffected. None of the measures of physical performance across the individual playing positions were affected by opposition team formation. Skill-related performance varied according to opposition formation: players as a whole performed more passes versus a 4-4-2 than a 4-2-3-1 (p<0.01), ground and aerial duels versus a 4-2-3-1 compared to a 4-4-2 (both p<0.01); 1-touch passes versus a 4-2-3-1 compared to a 4-4-2 (p<0.01) and a 4-3-3/4-5-1 (p<0.05). The mean number of touches per possession was highest versus a 4-4-2 compared to a 4-3-3/4-5-1 (p<0.01) and a 4-2-3-1 (p<0.01). While skill-related performance across the four individual playing positions was generally unaffected by opposition team formation, mean pass length was greater in central-midfielders against a 4-4-2 compared to 4-3-3/4-5-1 (p<0.05) and 4-2-3-1 (p<0.01) formations. In general, these findings suggest that physical performance in the reference team was not greatly affected by opposition team formation. In contrast, skill-related demands varied substantially according to opponent formation and may have consequences for tactical and technical preparation and team selection policies