3,204 research outputs found

    Simple, Inexpensive Method of Tagging Ictalurid Fishes for Individual Identification

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142125/1/naaq0152.pd

    Online beamline centering at PSI

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    Oriented right-angled Artin pro-\ell groups and maximal pro-\ell Galois groups

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    For a prime number \ell we introduce and study oriented right-angled Artin pro-\ell groups GΓ,λG_{\Gamma,\lambda}(oriented pro-\ell RAAGs for short) associated to a finite oriented graph Γ\Gamma and a continuous group homomorphism λ ⁣:ZZ×\lambda\colon\mathbb Z_\ell\to\mathbb Z_\ell^\times. We show that an oriented pro-\ell RAAG GΓ,λG_{\Gamma,\lambda} is a Bloch-Kato pro-\ell group if, and only if, (GΓ,λ,θΓ,λ)(G_{\Gamma,\lambda},\theta_{\Gamma,\lambda}) is an oriented pro-\ell group of elementary type generalizing a recent result of I. Snopche and P. Zalesskii. Here θΓ,λ ⁣:GΓ,λZp×\theta_{\Gamma,\lambda}\colon G_{\Gamma,\lambda}\to\mathbb Z_p^\times denotes the canonical \ell-orientation on GΓ,λG_{\Gamma,\lambda}. We invest some effort in order to show that oriented right-angled Artin pro-\ell groups share many properties with right-angled Artin pro-\ell-groups or even discrete RAAG's, e.g., if Γ\Gamma is a specially oriented chordal graph, then GΓ,λG_{\Gamma,\lambda} is coherent, generalizing a result of C. Droms. Moreover, in this case (GΓ,λ,θΓ,λ)(G_{\Gamma,\lambda},\theta_{\Gamma,\lambda}) has the Positselski-Bogomolov property generalizing a result of H. Servatius, C. Droms and B. Servatius for discrete RAAG's. If Γ\Gamma is a specially oriented chordal graph and Im(λ)1+4Z2{\rm Im}(\lambda)\subseteq 1+4\mathbb Z_2 in case that =2\ell=2, then H(GΓ,λ,F)Λ(Γ¨op){\rm H}^\bullet(G_{\Gamma,\lambda},\mathbb F_\ell) \simeq \Lambda^\bullet(\ddot{\Gamma}^{\rm op}) generalizing a well known result of M. Salvetti.Comment: The differences between the 1st version (Apr'23) and the 2nd are: correction of a couple of minor misprints, dedication to the memory of Avinoam Man

    Triplet lambs and their dams – a review of current knowledge and management systems

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    Triplet-bearing ewes and their lambs have the potential to improve flock productivity however, the lack of robust information on optimal nutrition and management is limiting their performance. In comparison to twins, the triplet lamb is; lighter, more metabolically challenged, has lower body temperature, and receives less colostrum and milk which combined results in lower survival rates and weaning weights. While scientifically based management guidelines are available for singletons and twins, guidelines are generally lacking for triplets. Although there is some knowledge on the impacts of nutrition, further studies are required to examine the impacts of varying feeding regimens in pregnancy and lactation, across the body condition range. Characterising the impacts of shelter and other paddock factors, stocking rate, mob size and human intervention would also be of benefit. Future studies must be large enough to allow for evaluation of lamb survival and litter birth weight variation

    Avaliação genética de seleções e híbridos de limões cravo, Volkameriano e Rugoso como porta-enxertos para laranjeiras Valência na presença da morte súbita dos citros.

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    Este estudo teve como objetivo realizar a avaliação genética da produção de frutos, eficiência produtiva e altura de laranjeiras Valência (Citrus sinensis) enxertadas em seleções e híbridos dos limões Cravo (C. limonia), Volkameriano (C. volkameriana) e Rugoso (C. jambhiri), em área endêmica para morte súbita dos citros (MSC). Foram avaliados 36 genótipos desses porta-enxertos, representados por cinco plantas cada, avaliados em cinco safras, do terceiro ao sétimo ano após o plantio. Sete dos genótipos avaliados apresentaram plantas com sintomas de MSC até o sétimo ano: Rangpur Otaheite orange 12901 (859), Rangpur Red Lime D.33.30 (866), Limão-Cravo EEL (871), Rangpur Borneo red (874), Citrus kokhai (1649), Limão-Rugoso 58329 (1655) e Limão- Cravo x Swingle B (1695). Para os genótipos que não manifestaram sintomas da doença, foram estimados parâmetros genéticos e fenotípicos e realizada a predição de valores genéticos dos indivíduos, visando à seleção e ao melhoramento genético para as características citadas, empregando-se o método REML/BLUP (máxima verossimilhança restrita/melhor predição linear não viciada). A análise de produção de frutos de cinco safras mostrou acurácia seletiva de 84,59%, tornando-se desnecessária a avaliação de maior número de safras. A seleção dos sete melhores genótipos proporcionou ganhos genéticos de 11,5% na produção de frutos, enquanto a do melhor genótipo conferiu ganho genético de 16,3%. As maiores médias genéticas preditas (>70,0 kg.pl-1) para produção de frutos foram obtidas pelos genótipos Limão-Cravo- Ipanema (1522), Santa- Bárbara-Red- Lime (884), Limão- Cravo- Limeira (863), Limão- Cravo- Taquaritinga (869), Limão- Rugoso- do -Cabo (1643), Rangpur- Rose Lime (868) e Limão- Cravo- da- Califórnia (1467). Já a acurácia seletiva da eficiência produtiva, para quatro colheitas, foi 77,4%. Para este caráter, as maiores médias genéticas (>8,0 kg.m-3) foram dos genótipos Rangpur- Lime x Trifoliata 3810 (1648), Rangpur- Lime x Trifoliata 5320 (1644), Limão- Cravo x Citrange- Carrizo (1524), Citrus pennivesiculata (880), Limão- Cravo x Trifoliata- Swingle A (1707), Rangpur- Rose- Lemon 124684 (864), Rangpur- Red -Lime D33.47 (867) e Limão- Cravo -Ipanema (1522). Dentre os 10 melhores genótipos para produção de frutos e para eficiência produtiva, apenas três são coincidentes: Rangpur- Rose -Lime (868), Citrus pennivesiculata (880) e Limão- Cravo-Ipanema (1522)

    Parental care sex differences in the brown bullhead, Ictalurus nebulosus (Pisces, Ictaluridae)

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    Males were the principal care-givers in the brown bullhead, Ictalurus nebulosus . Direct observations on individually tagged adults in nature revealed that males attended broods at closer distances than females and were the most frequent lone care-givers. However, females often participated in parental care and in some cases assumed the typical male role in the absence of the male. In the presence of her mate, females generally performed different care-giving functions than males. Females attended broods at a distance and chased other fishes more frequently than males. Males remained directly over the brood guarding. A series of mated pairs in each of three reproductive conditions were captured and examined. Different pairs were compared between reproductive conditions for body weight, body condition, gonadal-somatic index, and a gut-contents index. The inital costs of reproduction, as measured by weight loss, condition change, and gonadal-somatic index change, were more severe in females than males. During breeding and subsequent care-giving, males did little or no feeding whereas females increased their feeding during the same time period. However, males appeared to sustain only minor weight and condition losses due to care-giving. I suggest that males were the principal care-givers because the net benefits of remaining at the nest were greater than the net benefits of leaving. Males had little opportunity to mate with more than one female each season, and offspring had little chance of survival in the absence of a care-giving adult. Considerable variation in female behavior occurred which suggests that the net benefits of care-giving were nearly balanced with the net benefits of leaving the brood. The relative importance of feeding versus care-giving by females may vary with slight differences between females and the behavior of their mates as care-givers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46875/1/265_2004_Article_BF00299944.pd

    Absolute calibration of the LOPES antenna system

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    Radio emission in extensive air showers arises from an interaction with the geomagnetic field and is subject of theoretical studies. This radio emission has advantages for the detection of high energy cosmic rays compared to secondary particle or fluorescence measurement methods. Radio antennas like the LOPES30 antenna system are suited to investigate this emission process by detecting the radio pulses. The characteristic observable parameters like electric field strength and pulse length require a calibration which was done with a reference radio source resulting in an amplification factor representing the system behavior in the environment of the KASCADE-Grande experiment. Knowing the amplification factor and the gain of the LOPES antennas LOPES30 is calibrated absolutely for systematic analyses of the radio emission.Comment: 5 pages, Proceedings of International Workshop on Acoustic and Radio EeV Neutrino detection Activities: ARENA, May 17-19, 2005, DESY Zeuthe
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