Holographic descriptions of large N gauge dynamics

We use the AdS/CFT correspondence to study different aspects of large N dynamics of gauge theories in the strongly coupled regime. We present three models designed to capture some of the physics present in QCD at low energies or QCD-type theories such as walking tecnhicolor. We use the D3/D7 system to study chiral symmetry breaking in two different contexts: In the first model we break chiral symmetry with an arbitrary running coupling which has a pion in its spectrum. We derive integral equations for the quark condensate and pion decay constant by matching our model to a low energy chiral lagrangian and discuss the implications for technicolor theories. In the second model we study the on set of chiral symmetry breaking at the edge of the conformal window in QCD in the Veneziano limit and show a BKT-type transition. Finally, in the context of AdS/QCD we extend the ”hard wall” model to include the tensor operator ¯φσμνψ dual to a two form satisfying a self duality condition and study numerically the spectrum of vector mesons

Holography of the Conformal Window

Inspired by the model of Jarvinen and Kiritsis, we present a simple holographic model for the on set of chiral symmetry breaking at the edge of the conformal window in QCD in the Veneziano limit. Our most naive model enforces the QCD two loop running coupling on a D3/D7 holographic brane system. The mass of the holographic field, describing the chiral condensate in the model, is driven below the BF bound when the running is sufficiently strong, triggering chiral symmetry breaking for N_f/N_c<2.9. This model though contains too great a remnant of supersymmetry and does not correctly encode the perturbative anomalous dimensions of QCD. In a second model we impose the QCD anomalous dimension result and find chiral symmetry breaking sets in for N_f/N_c=4 at a BKT-type phase transition. In this case the transition is triggered when the anomalous dimension of the mass operator \gamma_m=1.Comment: 10 pages, 2 figures, v2: minor corrections, improved Figure

An improved model of vector mesons in holographic QCD

We analyze the sector of dimension-three vector meson operators in the "hard wall" model of holographic QCD, including the vector and axial currents, dual to gauge fields in the bulk, and the tensor operator $\bar{\psi}\sigma^{\mu\nu}\psi$, dual to a two-form field satisfying a complex self-duality condition. The model includes the effect of chiral symmetry breaking on vector mesons, that involves a coupling between the dual gauge field and the two-form field. We compute the leading logarithmic terms in the operator product expansion of two-point functions and the leading non-perturbative contribution to the tensor-vector correlator. The result is consistent with the operator product expansion of QCD. We also study the spectrum of vector mesons numerically.Comment: 19 page

PREDAÇÃO DE Boana raniceps (COPE, 1862) (ANURA: HYLIDAE) POR Leptophis ahaetulla (LINNAEUS, 1758) (SQUAMATA: COLUBRIDAE)

In this research, we report the predation of Boana raniceps (Cope, 1862) by Leptophis ahaetulla (Linnaeus, 1758) in the rural area of Candeias do Jamari municipality, Rondônia state, southwestern Brazilian Amazon. Leptophis ahaetulla is a diurnal arboreal snake that can be found in a variety of environments such as dryland forests, flooded forests, and plantations. Its diet consists mainly of anurans and may include lizards. Boana raniceps belongs to the B. albopuncatata group.  There are few well-described reports on the predatory behavior of anurans by L. ahaetulla, as studies are generally based on stomach contents and not on photographic records. There are also few reports on the defensive behaviors of B. raniceps. In this research, predation of Boana raniceps was by Leptophis ahaetulla lasted about 15 minutes until complete ingestion and occurred at 2:00 PM on July 05, 2020. During predation, B. raniceps performed the defensive behavior, making distress calls. Recording this predation is essential to improve knowledge about the natural history of the species described here.Keywords: Predation; amphibian; behavior; diet; snakes.Nesta pesquisa, relatamos a predação de Boana raniceps (Cope, 1862) por Leptophis ahaetulla (Linnaeus, 1758) na área rural do município de Candeias do Jamari, estado de Rondônia, sudoeste da Amazônia brasileira. Leptophis ahaetulla é uma cobra arbórea diurna que pode ser encontrada em diversos ambientes, como florestas de terra firme, florestas inundadas e plantações. Sua dieta consiste principalmente de anuros e pode incluir lagartos. A Boana raniceps pertence ao grupo B. albopuncatata.  Há poucos relatos bem descritos sobre o comportamento predatório dos anuros por L. ahaetulla, já que os estudos são geralmente baseados no conteúdo estomacal e não em registros fotográficos. Há também poucos relatos sobre os comportamentos defensivos de B. raniceps. Nesta pesquisa, a predação de B. raniceps por L. ahaetulla durou cerca de 15 minutos até a ingestão completa e ocorreu às 14h00 do dia 05 de julho de 2020. Durante a predação, B. raniceps executou o comportamento defensivo, fazendo chamadas de socorro. O registro desta predação é essencial para melhorar o conhecimento sobre a história natural das espécies aqui descritas.Palavras-chave: Predação, anfíbio, comportamento, dieta, serpentes

Underwater radio frequency image sensor using progressive image compression and region of interest

The increasing demand for underwater robotic intervention systems around the world in several application domains requires more versatile and inexpensive systems. By using a wireless communication system, supervised semi-autonomous robots have freedom of movement; however, the limited and varying bandwidth of underwater radio frequency (RF) channels is a major obstacle for the operator to get camera feedback and supervise the intervention. This paper proposes the use of progressive (embedded) image compression and region of interest (ROI) for the design of an underwater image sensor to be installed in an autonomous underwater vehicle, specially when there are constraints on the available bandwidth, allowing a more agile data exchange between the vehicle and a human operator supervising the underwater intervention. The operator can dynamically decide the size, quality, frame rate, or resolution of the received images so that the available bandwidth is utilized to its fullest potential and with the required minimum latency. The paper focuses first on the description of the system, which uses a camera, an embedded Linux system, and an RF emitter installed in an OpenROV housing cylinder. The RF receiver is connected to a computer on the user side, which controls the camera monitoring parameters, including the compression inputs, such as region of interest (ROI), size of the image, and frame rate. The paper focuses on the compression subsystem and does not attempt to improve the communications physical media for better underwater RF links. Instead, it proposes a unified system that uses well-integrated modules (compression and transmission) to provide the scientific community with a higher-level protocol for image compression and transmission in sub-sea robotic interventions

TAMANHO DA NINHADA DE Xenodon rabdocephalus (WIED-NEUWIED, 1824) (SQUAMATA: COLUBRIDAE) NO SUDOESTE DA AMAZÓNIA BRASILEIRA

This report adds information on the reproduction of Xenodon rabdocephalus (Wied-Neuwied, 1824) and describes the clutch size in a little-studied region of the Brazilian Amazon. We conducted field observations at the Military Jungle Police Base in the municipality of Porto Velho, state of Rondônia, southwestern Brazilian Amazon (9°5'31.56"S, 64°1'40.08"W). This individual of X. rabdocephalus was found to have a clutch of 11 eggs, with a size range of 26-36 mm (mean 29.36 ± 3.23 mm). The specimen analyzed in this report was deposited in the Coleção Herpetológica da Universidade Federal de Rondônia. We indicate the need for studies focused on the variation in the reproductive behaviour of the species in relation to seasonal fluctuation. Finally, reports of this kind help to understand the reproductive habits of X. rabdocephalus in nature.Keywords: false fer-de-lance; Eggs; Reproductive Behaviour; Natural history; Reproduction.Este relato acrescenta informação sobre a reprodução de Xenodon rabdocephalus (Wied-Neuwied, 1824) e descreve o tamanho da ninhada desta espécie numa região pouco estudada da Amazônia brasileira. Realizamos observações de campo na Base de Selva da Polícia Militar no município de Porto Velho, estado de Rondônia, sudoeste da Amazônia brasileira (9°5'31.56"S, 64°1'40.08"W). O indivíduo de X. rabdocephalus foi observado com uma ninhada de 11 ovos. O espécime analisado neste trabalho foi depositado na Coleção Herpetológica da Universidade Federal de Rondônia. Indicamos a necessidade de estudos centrados na variação do comportamento reprodutivo da espécie em relação à variação sazonal. Por fim, relatos deste tipo ajudam a compreender os hábitos reprodutivos da X. rabdocephalus na natureza.Palavras-chave: Jararaca Falsa, Ovos, Comportamento Reprodutivo, História natural, Reprodução

Human consumption of meat from roadkilled animals in the Southwestern Amazon

The harvest of meat from wild animals is essential for the nutrition of many human populations in the Neotropics. Specific techniques are used to access wild meat, but collecting meat from road killed animals, or purposely run over animals to kill and consume the meat have not been documented so far. In this study we interviewed four residents of the state of Rondônia who claimed to consume roadkilled animals. Respondents cited only medium and large mammals (10 species in total) as the group from which wild meat is harvested, with one respondent claiming to intentionally run over the animals. The interviewees analyse the smell/putrefaction, swelling and exposure of viscera as criteria for not collecting the meat. The meat from roadkilled animals may pose a risk to the health of humans who consume it due to the foodborne diseases it may spread after the decomposition process. In addition, the practice of running over animals for consumption of their meat can cause potential impacts to the fauna and humans since it can reduce animal numbers and also cause serious accidents. Further investigations are needed to clarify whether this is widespread phenomenon occurring in other places of the Amazon and of the Neotropics

Administración de los servicios de salud de la Unidad Departamental de Salud Lima Ciudad, Hospital de Apoyo I Santa Rosa y Centros de Salud de Magdalena y San Miguel

El cuidado de la salud constituye un imperativo categórico para ser considerada como una prioridad impostergable, ya que el poblador sano está en aptitud de conformar una población económicamente activa, que contribuirá al desarrollo Y fortalecimiento de la Sociedad. Este concepto, llevó a muchos países en desarrollo a crear vastos sistemas de atención de la salud financiados por el sector público, gratuitos o a bajo costo. La crisis financiera de los ochenta obligó a muchos de estos países a disminuir sus presupuestos en los servicios de salud. entre estos el Perú ha atravesado cíclicamente por etapas críticas, pero ninguna tan seria y prolongada como la presente, con un grave deterioro social, político y administrativo. Lo que ha llevado a una degradación de las condiciones de vida de la mayor parte de la población, conformada por los sectores populares de menores recursos y ahora por la clase media, conducidos a situaciones de extrema pobreza (45 % de la población); esto obligó a realizar ajustes económicos drásticos Y restringir los gastos sociales del gobierno. La disminución sustancial en los gastos del gobierno en lo referente al sector salud, ha producido un deterioro gradual y sustancial en los servicios de salud y por lo tanto en la situación de salud del país; esto ha incentivado al Ministerio de Salud a plantear politices orientadas a concebir Estrategias que tengan un alto grado de sustentación que permitan desarrollar planee de salud a corto, mediano y largo plazo que sean consistentes y factibles de ser ejecutados. Por lo que el estudio de la administración de salud y su problemática, como factor coadyuvante en el deterioro de los servicios de salud, cobra gran importancia para el planteamiento de soluciones que permitan redefinir los lineamientos de la política de salud.Trabajo académic