Geomorphological investigation of multiphase glacitectonic composite ridge systems in Svalbard

Some surge-type glaciers on the High-Arctic archipelago of Svalbard have large glacitectonic composite ridge systems at their terrestrial margins. These have formed by rapid glacier advance into proglacial sediments during the active surge phase, creating multicrested moraine complexes. Such complexes can be formed during single surge advances or multiple surges to successively less-extensive positions. The few existing studies of composite ridge systems have largely relied on detailed information on internal structure and sedimentology to reconstruct their formation and links to surge processes. However, natural exposures of internal structure are commonly unavailable, and the creation of artificial exposures is often problematic in fragile Arctic environments. To compensate for these issues, we investigate the potential for reconstructing composite ridge system formation based on geomorphological evidence alone, focusing on clear morphostratigraphic relationships between ridges within the moraine complex and relict meltwater channels/outwash fans. Based on mapping at the margins of Finsterwalderbreen (in Van Keulenfjorden) and Grønfjordbreen (in Grønfjorden), we show that relict meltwater channels that breach outer parts of the composite ridge systems are in most cases truncated upstream within the ridge complex by an inner pushed ridge or ridges at their ice-proximal extents. Our interpretation of this relationship is that the entire composite ridge system is unlikely to have formed during the same glacier advance but is instead the product of multiple advances to successively less-extensive positions, whereby younger ridges are emplaced on the ice-proximal side of older ridges. This indicates that the Finsterwalderbreen composite ridge system has been formed by multiple separate advances, consistent with the cyclicity of surges. Being able to identify the frequency and magnitude of former surges is important as it provides insight into the past behaviour of surge-type glaciers and, if absolute dating is possible, allows for the assessment of surge-type glacier response to climate change on decadal to centennial timescales. Although further investigations into the internal structure of these deposits should be sought where possible, our study demonstrates that geomorphology could be an invaluable tool for reconstructing the formation of composite ridge systems

Manual mapping of drumlins in synthetic landscapes to assess operator effectiveness

Mapped topographic features are important for understanding processes that sculpt the Earth's surface. This paper presents maps that are the primary product of an exercise that brought together 27 researchers with an interest in landform mapping wherein the efficacy and causes of variation in mapping were tested using novel synthetic DEMs containing drumlins. The variation between interpreters (e.g. mapping philosophy, experience) and across the study region (e.g. woodland prevalence) opens these factors up to assessment. A priori known answers in the synthetics increase the number and strength of conclusions that may be drawn with respect to a traditional comparative study. Initial results suggest that overall detection rates are relatively low (34–40%), but reliability of mapping is higher (72–86%). The maps form a reference dataset

Gravitational Lensing at Millimeter Wavelengths

With today's millimeter and submillimeter instruments observers use gravitational lensing mostly as a tool to boost the sensitivity when observing distant objects. This is evident through the dominance of gravitationally lensed objects among those detected in CO rotational lines at z>1. It is also evident in the use of lensing magnification by galaxy clusters in order to reach faint submm/mm continuum sources. There are, however, a few cases where millimeter lines have been directly involved in understanding lensing configurations. Future mm/submm instruments, such as the ALMA interferometer, will have both the sensitivity and the angular resolution to allow detailed observations of gravitational lenses. The almost constant sensitivity to dust emission over the redshift range z=1-10 means that the likelihood for strong lensing of dust continuum sources is much higher than for optically selected sources. A large number of new strong lenses are therefore likely to be discovered with ALMA, allowing a direct assessment of cosmological parameters through lens statistics. Combined with an angular resolution <0.1", ALMA will also be efficient for probing the gravitational potential of galaxy clusters, where we will be able to study both the sources and the lenses themselves, free of obscuration and extinction corrections, derive rotation curves for the lenses, their orientation and, thus, greatly constrain lens models.Comment: 69 pages, Review on quasar lensing. Part of a LNP Topical Volume on "Dark matter and gravitational lensing", eds. F. Courbin, D. Minniti. To be published by Springer-Verlag 2002. Paper with full resolution figures can be found at ftp://oden.oso.chalmers.se/pub/tommy/mmviews.ps.g

Níveis de proteína bruta para juvenis de pirarucu

The objective of this work was to verify the effect of four protein levels on pirarucu, Arapaima gigas, growth performance. One hundred and twenty pirarucu juveniles, with an average weight of 120.6±3.5 g, were stocked into 12 floating cages with 1 m3 (ten fish per cage), in a complete randomized design with four treatments (32.7%, 39.3%, 43.4% and 48.6% crude protein), in three replicates each. After 45 days, results showed that diet with highest protein level (48.6%) produced a better weight gain, specific growth rate, and differentiated body composition. Feed conversion and protein efficiency ratios did not show any differences among treatments. The dietary protein level required to produce maximum growth is 48.6%

Hierarchically Acting Sterile Neutrinos

We propose that a hierarchical spectrum of sterile neutrinos (eV, keV, $10^{13-15}$ GeV) is considered to as the explanations for MiniBooNE and LSND oscillation anomalies, dark matter, and baryon asymmetry of the universe (BAU) respectively. The scenario can also realize the smallness of active neutrino masses by seesaw mechanism.Comment: 4 pages, 1 tabl

Diferentes fontes protéicas para a alimentação do jundiá (Rhamdia quelen) Different protein sources for jundiá (Rhamdia quelen) feeding

O objetivo deste trabalho foi verificar o crescimento e a composição de filés de juvenis de jundiá (Rhamdia quelen) alimentados com diferentes fontes protéicas, durante 60 dias. Utilizaram-se 540 peixes (peso médio inicial=15,00&plusmn;0,62g, comprimento total inicial=11,98&plusmn;0,35cm) distribuídos ao acaso em 18 caixas de 280L (30 peixes/caixa) em sistema de recirculação de água. Testaram-se seis tratamentos (com três repetições): CL (farinha de carne e ossos + levedura), SL (farelo de soja + levedura), S (somente farelo de soja), CS (farinha de carne e ossos + farelo de soja), PL (farinha de peixe + levedura) e PS (farinha de peixe + farelo de soja). Foram estimados parâmetros de desempenho (peso, comprimento total, fator de condição, taxa de crescimento específico, taxa de eficiência protéica) aos 30 e 60 dias, composição centesimal e taxas de deposição de proteína e gordura nos filés ao final do experimento. Os parâmetros peso, comprimento total e taxa de crescimento específico foram superiores nos tratamentos compostos pela combinação das farinhas de origem animal (carne e ossos e peixe) com farelo de soja. A quantidade de gordura e proteína depositada no filé dos peixes também foi superior nestes tratamentos (CS e PS). Os rendimentos de carcaça e filé não diferiram entre os tratamentos. A combinação das farinhas de carne e ossos e de peixes com farelo de soja possibilita bom crescimento e maior deposição de proteína e gordura nos filés de juvenis de jundiá.<br>This study aimed at verifing the growth and fillet composition of jundiá juveniles (Rhamdia quelen) fed with different protein sources, for 60 days. It was used 540 fish (initial weight=15.00&plusmn;0.62g, initial length=11.98&plusmn;0.35cm) at random distributed in 18 tanks of 280L (30 fish/tank) in a water re-use system. 6 treatments were tested (with 3 repetitions): CL (meat and bone meal + yeast), SL (soybean meal + yeast), S (only soybean meal), CS (meat and bone meal + soybean meal), PL (fish meal + yeast) and PS (fish meal + soybean meal). They were dear development parameters (weight, total length, condition factor, specific growth rate, protein efficiency ratio) to the 30 and 60 days, centesimal composition and protein and fat deposition in the filets at the end of the experiment. The parameters weight, total length and specific growth rate were higher in the treatments composed by the combination of the feedstufs of animal origin (meat and bone and fish meal) with soybean meal. The fat and protein deposited in the filet of the fish was also higher in these treatments (CS and PS). The carcass and filet yeld didn’t differ among the treatments. This concluded that the combination of meat, and bone, and fish meal with soybean meal make good growth and higher protein and fat deposition in the filets of jundiá juveniles

Cucumber seedling dependence on cotyledonary leaves for early growth Dependência das folhas cotiledonares para o crescimento inicial de pepino

The objective of this work was to evaluate the dependence of cucumber (Cucumis sativus L.) seedlings on cotyledonary leaves for early growth and establishment. Sets of two uniform emerging seedlings were used to quantify the initial growth and dry matter accumulation, as well as the intensity and stage of cotyledon damage in seedling establishment and to determine cotyledon protein, amino acid and carbohydrate contributions to the growing seedling. Cucumber seedling establishment was found to be highly dependent on cotyledonary leaves. Root system establishment was highly dependent on the health of the aerial part. One cotyledon was enough to maintain aerial growth of seedlings after unfolding the first true leaf. Cucumber seedlings depended on both cotyledons to keep root system growth at least until leaf area was equivalent to cotyledon area. Covering one or both cotyledons of seedlings with one unfolded leaf increased carbohydrate content of uncovered cotyledon and leaves compared with control seedlings. Cucumber seedlings are highly dependent on cotyledonary leaves and aerial parts are less dependent than root system. Cotyledon damage at early stages of plant establishment would adversely impact crop yield by reducing plant density, an important yield component, or slowing down seedling growth and establishment.<br>O objetivo deste trabalho foi estudar o desempenho das folhas cotiledonares no crescimento inicial e estabelecimento de plântulas de pepino (Cucumis sativus L.). Grupos de duas plântulas uniformemente emergidas foram utilizados para quantificar o crescimento inicial e acúmulo de matéria seca, o efeito da intensidade e época de remoção dos cotilédones sobre o estabelecimento da plântula, e a contribuição de proteínas, aminoácidos e carboidratos dos cotilédones para o crescimento inicial. O estabelecimento das plântulas de pepino foi altamente dependente das folhas cotiledonares. As folhas cotiledonares foram fundamentais para o estabelecimento do sistema radicular. A presença de um cotilédone após a emissão da primeira folha verdadeira foi suficiente para manter o crescimento da parte aérea da plântula. Plântulas de pepino foram dependentes de ambas as folhas cotiledonares para sustentar o crescimento do sistema radicular, pelo menos até a equivalência entre área foliar e cotiledonar. A cobertura de uma ou ambas folhas cotiledonares antes da emissão da primeira folha verdadeira aumentou o conteúdo de carboidratos no cotilédone descoberto e nas folhas, comparado com a testemunha. O crescimento inicial de plântulas de pepino é altamente dependente das folhas cotiledonares, sendo a parte aérea menos dependente do que o sistema radicular. Danos nos cotilédones durante o crescimento inicial podem afetar o rendimento pela redução da densidade de plantas, um importante componente do rendimento, ou da taxa de crescimento e estabelecimento da plântula, que afeta a uniformidade da cultura

Efeito da suplementação de metionina e/ou lisina no crescimento e na sobrevivência de alevinos de peixe-rei (Odontesthes bonariensis) Effect of methionine and lysine supplementation on growth and survival of pejerrey (Odontesthes bonariensis) fingerlings

Para avaliar o efeito da suplementação de metionina e lisina sobre o desempenho de alevinos de peixe-rei (Odontesthes bonariensis), estabeleceu-se um experimento completamente casualizado com quatro tratamentos. A dieta T1 (controle) continha as concentrações de metionina e lisina disponíveis nos produtos usados na formulação da mesma. A dieta T2 foi suplementada com 4,76% de DL-metionina; a dieta T3, com 4,76% de L-lisina; e a dieta T4, com 4,54% de DL-metionina e 4,54% de L-lisina. As dietas suplementadas com metionina foram mais eficientes que a dieta-controle e a suplementada apenas com lisina, pois esta não apresentou diferença em relação à dieta-controle, comprovando que a quantidade de lisina disponível nos produtos utilizados na elaboração das dietas atende às necessidades dos alevinos de peixe-rei. A quantidade de metionina disponível nestas formulações é insuficiente para o bom desempenho dos alevinos, devendo ser suplementada.<br>A completely randomized experiment was run to evaluate the effect of methionine and lysine supplementation on the pejerrey (Odontesthes bonariensis) fingerlings performance. Four treatments were compared: Diet T1 control, with available contents mehionine and lysine in products used in formulation of diets; Diet T2 supplemented with 4.76% of DL- methionine; Diet T3 supplemented with 4.76% of L- lysine and Diet T4 with 4.54% of DL methionine and 4.54% of L lysine. Resulted showed that diets containing methionine were more efficient than control diet and diet with lysine only. Control diet did not differ from diet with lysine supplementation only. It is shown that contents of available lysine in products used in the formulation of diets meet pejerrey fingerlings requirements. Amounts of methionine in control diet are insufficient for fingerlings growth. A supplementation of this aminoacid is required to maximize performance