Geometrical aspects of isoscaling

The property of isoscaling in nuclear fragmentation is studied using a simple bond percolation model with ``isospin'' added as an extra degree of freedom. It is shown analytically, first, that isoscaling is expected to exist in such a simple model with the only assumption of fair sampling with homogeneous probabilities. Second, numerical percolations of hundreds of thousands of grids of different sizes and with different $N$ to $Z$ ratios confirm this prediction with remarkable agreement. It is thus concluded that isoscaling emerges from the simple assumption of fair sampling with homogeneous probabilities, a requirement which, if put in the nomenclature of the minimum information theory, translates simply into the existence of equiprobable configurations in maximum entropy states

In Vitro Activity Of Artemisia Annua L (asteraceae) Extracts Against Rhipicephalus (boophilus) Microplus [atividade In Vitro De Extratos De Artemisia Annua L (asteraceae) Sobre Rhipicephalus (boophilus) Microplus]

The activity of plant extracts on parasites may indicate groups of substances that are potentially useful for controlling Rhipicephalus (Boophilus) microplus. The aim of the present study was to investigate the in vitro action of Artemisia annua extracts on this tick. The concentrations of the sesquiterpene lactones artemisinin and deoxyartemisinin present in plant extracts were quantified via high-performance liquid chromatography. Four extracts produced from the concentrated crude extract (CCE) were evaluated on larvae using the impregnated paper method, with readings after 24 hours of incubation. The engorged females were immersed in the CCE and in its four derived extracts for five minutes, with incubation for subsequent analysis of biological parameters. The extracts were not effective on the larvae at the concentrations tested (3.1 to 50 mg.mL-1). The CCE showed greater efficacy on engorged females (EC50 of 130.6 mg.mL-1 and EC90 of 302.9 mg.mL-1) than did the derived extracts. These results tend to confirm that the action of artemisinin on engorged females of R. (B.) microplus is conditional to their blood intake. In this case, in vitro methods would be inadequate for effective evaluation of the action of A. annua on R. (B.) microplus.2013135Amaral, N.K., Guidelines for the evaluation of ixodicides against the cattle tick Boophilus microplus (Canestrini, 1887) (Acari: Ixodidae) (1993) Revista Brasileira De Parasitologia Veterinária, 2 (2), pp. 144-151(2009) Anuário Da Pecuária Brasileira, p. 360. , ANUALPEC, Sao Paulo: Angra FNP PesquisasBorges, L.M.F., Acao do extrato hexanico de frutos maduros de Melia azedarach (Meliaceae) sobre Boophilus microplus (Acari: Ixodidae) em bezerros infestados artificialmente (2005) Revista De Patologia Tropical, 34 (1), pp. 53-59Cala, A.C., (2010) Avaliação Da Atividade De Artemisia Annua L., Melia Azedarach L. E Trichilia Claussenii C. Sobre Nematódeos Gastrintestinais De Ovinos, p. 64. , Dissertacao (Mestrado)- Universidade Estadual Paulista, Faculdade de Ciencias Agrarias e Veterinarias, JaboticabalCeleghini, R.M.S., Desenvolvimento e validacao de metodologia analitica por CLAE-IR para determinacao de artemisinina em Artemisia annua L (2009) Química Nova, 32 (4), pp. 875-878Chagas, A.C.S., Efeito acaricida de oleos essenciais e concentrados emulsionaveis de Eucalyptus em Boophilus microplus (2002) Brazilian Journal of Veterinary Research and Animal Science, 39 (5), pp. 247-253Chagas, A.C.S., Sensibilidade do carrapato Boophilus microplus a solventes (2003) Ciência Rural, 33 (1), pp. 109-114Creek, D.J., Kinetics of ironmediated artemisinin degradation:Effect of solvent composition and iron salt (2005) Journal of Pharmaceutical Sciences, 94 (8), pp. 1820-1829Drummond, R.O., Boophilus annulatus and B. Microplus: Laboratory tests of insecticides (1973) Journal of Economic Entomology, 66 (1), pp. 130-133Ekanem, A.P., Brisibe, E.A., Effects of ethanol extract of Artemisia annua L. Against monogenean parasites of Heterobranchus longifilis (2010) Parasitology Research, 106 (5), pp. 1135-1139Fernandes, F.F., Freitas, E.P.S., Acaricidal activity of an oleoresinous extract from Copaifera reticulata (Leguminosae: Caesalpinioideae against larvae of the southern cattle tick, Riphicephalus (Boophilus) microplus (Acari:Ixodidae) (2007) Veterinary Parasitology, 147 (1-2), pp. 150-154Ferreira, J.F.S., Agrotechnological aspects of the anti-malarial plant Artemisia annua and its potential use in animal health in Appalachia (2006) International Symposium on Perfume, Aromatic and Medicinal Plants, (2-4), pp. 797-804. , Revue de Regions Arides - Numero special - Actes du seminaire international les Plants a Parfum, Aromatiques et Medicinales (English version: International Center for Agricultural Research in Dry AreasFerreira, J.F.S., Nutrient Deficiency in the Production of Artemisinin, Dihydroartemisinic Acid, and Artemisinic Acid in Artemisia annua L (2007) Journal of Agricultural and Food Chemistry, 55 (5), pp. 1686-1694Ferreira, J.F.S., Gonzalez, J.M., Chemical and biological stability of artemisinin in bovine rumen fluid and its kinetics in goats (Capra hircus) (2008) Revista Brasileira De Parasitologia Veterinária, 17 (SUPPL. 1), pp. 103-109Furlong, J., O carrapato dos bovinos e a resistencia: Temos o que comemorar? (2007) A Hora Veterinária, 159, pp. 26-32Grisi, L., Impacto economico das principais ectoparasitoses em bovinos no Brasil (2002) A Hora Veterinária, 21 (125), pp. 8-10Heimerdinger, A., Extrato alcoolico de Capim-cidreira (Cymbopogon citratus) no controle do Boophilus microplus em bovinos (2006) Revista Brasileira De Parasitologia Veterinária, 15 (1), pp. 37-39Idris, U.A., Adam, S.E., Tartour, G., The anthelmintic efficacy of Artemisia herba-alba against Haemonchus contortus infection in goats (1982) Animal Health Quarterly, 22 (3), pp. 138-143Iqbal, Z., Anthelmintic activity of Artemisia brevifolia in sheep (2004) Journal of Ethnopharmacology, 93 (2), pp. 265-268Keiser, J., Artesunate and artemether are effective fasciolicides in the rat model and in vitro (2006) Journal of Antimicrobial Chemotherapy, 57 (6), pp. 1139-1145Keiser, J., Efficacy and safety of artemether against a natural Fasciola hepatica infection in sheep (2008) Parasitology Research, 103 (3), pp. 517-522Keiser, J., Utzinger, J., Food-borne trematodiasis: Current chemotherapy and advances with artemisinins and synthetic trioxolanes (2007) Trends In Parasitology, 23 (11), pp. 555-562Klayman, D.L., Qinghaosu (Artemisinin): Na antimalarial drug from China (1985) Science, 228 (4703), pp. 1049-1055La-Scalea, M.A., Silva, H.S.R.C., Ferreira, E., Reducao voltametrica de artemisinina e sua interacao com grupo heme (hemina) (2007) Brazilian Journal of Pharmaceutical Sciences, 43 (3), pp. 371-383Martins, R.M., Estudio in vitro de la accion acaricida del aceite esencial de la graminea Citronela de Java (Cymbopogon winterianus Jowitt) en la garrapata Boophilus microplus (2006) Revista Brasileira De Plantas Medicinais De Botucatu, 8 (2), pp. 71-78Meshnick, S.R., Second-generation antimamalarial endoperoxides (1996) Parasitology Today, 12 (2), pp. 79-82Ribeiro, V.L.S., Acaricidal properties of extracts from the aerial parts of Hypericum polyanthemum on the cattle tick Boophilus microplus (2007) Veterinary Parasitology, 147 (1-2), pp. 199-203Rodrigues, R.A.F., Otimizacao do processo de extracao e isolamento do antimalarico artemisinina a partir de Artemisia annua L (2006) Química Nova, 29 (2), pp. 368-372Silva, H.S.R.C., (2006) Antimaláricos Potenciais: Pró-fármacos Poliméricos E Formas De Liberação Controlada De Artemisinina, p. 209. , Tese (Doutorado)-Universidade de Sao Paulo, Sao PauloSimoes, C.M., (2004) Farmacognosia: Da Planta Ao Medicamento, p. 1102. , 5. ed. Porto Alegre: Editora da UFRGSFlorianopolis: Editora da UFSCTaranto, A.G., Estudo sobre o mecanismo de acao da artemisinina e dos endoperoxidos, a mais nova classe de agents antimalaricos (2006) Sitientibus, 34, pp. 47-58Tariq, K.A., Anthelmintic activity of extracts of Artemisia absinthium against ovine nematodes (2009) Veterinary Parasitology, 160 (1-2), pp. 83-8

Benznidazole-resistance in Trypanosoma cruzi: evidence that distinct mechanisms can act in concert.

Benznidazole is the main drug used to treat Trypanosoma cruzi infections. However, frequent instances of treatment failure have been reported. To better understand potential resistance mechanisms, we analysed three clones isolated from a single parasite population that had undergone benznidazole-selection. These clones exhibited differing levels of benznidazole-resistance (varying between 9 and 26-fold), and displayed cross-resistance to nifurtimox (2 to 4-fold). Each clone had acquired a stop-codon-generating mutation in the gene which encodes the nitroreductase (TcNTR) that is responsible for activating nitroheterocyclic pro-drugs. In addition, one clone had lost a copy of the chromosome containing TcNTR. However, these processes alone are insufficient to account for the extent and diversity of benznidazole-resistance. It is implicit from our results that additional mechanisms must also operate and that T. cruzi has an intrinsic ability to develop drug-resistance by independent sequential steps, even within a single population. This has important implications for drug development strategies

Reduction of temporomandibular joint (TMJ) luxation in a horse - case report

ABSTRACT Luxation of the temporomandibular joint (TMJ) in horses, despite being an uncommon condition, is often associated with local trauma involving the head. Its clinical importance is mainly related to the painful injury and impairment of the multiple movements involved in chewing and breaking foods. The objective of the current work is to describe the manual reduction technique of TMJ dislocation in a 6-year-old Mangalarga Marchador stallion with a history of inability to close the oral cavity and lateral displacement of the mandible. In the radiographic and ultrasonographic evaluation of the region a rostral displacement of the mandibular condyle was observed. Manual reduction was effective with the patient under dissociative anesthesia, progressing to medical discharge within 12 days

Growth inhibitory effects of 3′-nitro-3-phenylamino nor-beta-lapachone against HL-60: A redox-dependent mechanism

AbstractIn this study, the cytotoxicity, genotoxicity and early ROS generation of 2,2-dimethyl-(3H)-3-(N-3′-nitrophenylamino)naphtho[1,2-b]furan-4,5-dione (QPhNO2) were investigated and compared with those of its precursor, nor-beta-lapachone (nor-beta), with the main goal of proposing a mechanism of antitumor action. The results were correlated with those obtained from electrochemical experiments held in protic (acetate buffer pH 4.5) and aprotic (DMF/TBABF4) media in the presence and absence of oxygen and with those from dsDNA biosensors and ssDNA in solution, which provided evidence of a positive interaction with DNA in the case of QPhNO2. QPhNO2 caused DNA fragmentation and mitochondrial depolarization and induced apoptosis/necrosis in HL-60 cells. Pre-treatment with N-acetyl-l-cysteine partially abolished the observed effects related to the QPhNO2 treatment, including those involving apoptosis induction, indicating a partially redox-dependent mechanism. These findings point to the potential use of the combination of pharmacology and electrochemistry in medicinal chemistry

Anisotropy studies around the galactic centre at EeV energies with the Auger Observatory

Data from the Pierre Auger Observatory are analyzed to search for anisotropies near the direction of the Galactic Centre at EeV energies. The exposure of the surface array in this part of the sky is already significantly larger than that of the fore-runner experiments. Our results do not support previous findings of localized excesses in the AGASA and SUGAR data. We set an upper bound on a point-like flux of cosmic rays arriving from the Galactic Centre which excludes several scenarios predicting sources of EeV neutrons from Sagittarius $A$. Also the events detected simultaneously by the surface and fluorescence detectors (the `hybrid' data set), which have better pointing accuracy but are less numerous than those of the surface array alone, do not show any significant localized excess from this direction.Comment: Matches published versio

Atmospheric effects on extensive air showers observed with the Surface Detector of the Pierre Auger Observatory

Atmospheric parameters, such as pressure (P), temperature (T) and density, affect the development of extensive air showers initiated by energetic cosmic rays. We have studied the impact of atmospheric variations on extensive air showers by means of the surface detector of the Pierre Auger Observatory. The rate of events shows a ~10% seasonal modulation and ~2% diurnal one. We find that the observed behaviour is explained by a model including the effects associated with the variations of pressure and density. The former affects the longitudinal development of air showers while the latter influences the Moliere radius and hence the lateral distribution of the shower particles. The model is validated with full simulations of extensive air showers using atmospheric profiles measured at the site of the Pierre Auger Observatory.Comment: 24 pages, 9 figures, accepted for publication in Astroparticle Physic

Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter

Data collected by the Pierre Auger Observatory through 31 August 2007 showed evidence for anisotropy in the arrival directions of cosmic rays above the Greisen-Zatsepin-Kuz'min energy threshold, \nobreak{$6\times 10^{19}$eV}. The anisotropy was measured by the fraction of arrival directions that are less than $3.1^\circ$ from the position of an active galactic nucleus within 75 Mpc (using the V\'eron-Cetty and V\'eron $12^{\rm th}$ catalog). An updated measurement of this fraction is reported here using the arrival directions of cosmic rays recorded above the same energy threshold through 31 December 2009. The number of arrival directions has increased from 27 to 69, allowing a more precise measurement. The correlating fraction is $(38^{+7}_{-6})$, compared with $21$ expected for isotropic cosmic rays. This is down from the early estimate of $(69^{+11}_{-13})$. The enlarged set of arrival directions is examined also in relation to other populations of nearby extragalactic objects: galaxies in the 2 Microns All Sky Survey and active galactic nuclei detected in hard X-rays by the Swift Burst Alert Telescope. A celestial region around the position of the radiogalaxy Cen A has the largest excess of arrival directions relative to isotropic expectations. The 2-point autocorrelation function is shown for the enlarged set of arrival directions and compared to the isotropic expectation.Comment: Accepted for publication in Astroparticle Physics on 31 August 201