Zero-field Kondo splitting and quantum-critical transition in double quantum dots

Double quantum dots offer unique possibilities for the study of many-body correlations. A system containing one Kondo dot and one effectively noninteracting dot maps onto a single-impurity Anderson model with a structured (nonconstant) density of states. Numerical renormalization-group calculations show that while band filtering through the resonant dot splits the Kondo resonance, the singlet ground state is robust. The system can also be continuously tuned to create a pseudogapped density of states and access a quantum critical point separating Kondo and non-Kondo phases.Comment: 4 pages, 4 figures; Accepted for publication in Physical Review Letter

Avaliação do sistema radicular de Lima Ácida Tahiti em dois sistemas de manejo.

Para que as plantas cítricas tenham longevidade é necessário que o sistema radicular possa se desenvolver sem limitações. Rezende et al. (2002) registram o desenvolvimento prejudicado do sistema radicular de citros nos solos coesos dos Tabuleiros Costeiros, com as plantas geralmente exibindo sistema radicular superficial e enovelamento da raiz principal. A utilização de práticas de manejo de solo como, uso de coberturas vegetais e subsolagem, melhoram a morfologia da planta, uma melhor distribuição do sistema radicular permite explorar maior volume de solo para absorção de nutrientes e principalmente de água em profundidade. A produção citrícola nos Tabuleiros Costeiros, onde predominam Latossolos Amarelos e Argissolos Amarelos, caracterizados como profundos, ácidos e com presença de horizontes coesos (Jacomine et al., 1977), é realizada praticamente sem uso de irrigação, pois a região dispõe de uma distribuição de chuvas regular durante 9 a 10 meses/ano (CNPMF, 1993). Práticas culturais, como a utilização de leguminosas nas entrelinhas e herbicidas nas linhas, em áreas subsoladas a 0,50 m de profundidade, que foram capazes de aumentar o volume do sistema radicular dos citros neste ecossistema entre 68 e 148% e a produção de frutos entre 28 e 40%, respectivamente (Carvalho et al.,1999). O objetivo deste trabalho foi avaliar o sistema radicular da Lima Ácida Tahiti, verificando a capacidade das raízes de explorar o solo, comparando dois sistemas de cultivo.pdf 220

Evaluation of the estate nutritional of mango tree, variety Tommy Atkins in Submiddle São Francisco river Valley, calculation of the indexes DRIS.

Sixty three representative orchards of mango tree in the Submiddle São Francisco River Valley in the Northeast of Brazil, were evaluated by the integrated system of diagnosis and recommendation (DRIS), having as reference population productivity equal or superior to 250 kg/plant

State nutritional of mango tree, variety Tommy Atkins, and quality postharvest in the Submiddle São Francisco river Valley.

Sixty three commercial orchards of mango tree, variety Tommy Atkins, with seven or more years of age, were evaluated for fruit productivity, leaf nutrient contents and soil physical and chernical characteristics

Desempenho de bubalinos para carne no Estado do Acre.

Com o objetivo de avaliar o comportamento produtivo de bubalinos para carne, está sendo conduzido na Fazenda Experimental da UEPAE de Rio Branco, um projeto de pesquisa em sistemas de produção.bitstream/item/145806/1/1147.pd

Both cetaceans in the Brazilian Amazon show sustained, profound population declines over two decades

<div><p>Obligate river dolphins occur only in the rivers of Asia and South America, where they are increasingly subject to damaging pressures such as habitat degradation, food competition and entanglement in fishing gear as human populations expand. The Amazon basin hosts two, very different, dolphins—the boto or Amazon river dolphin (<i>Inia geoffrensis</i>) and the smaller tucuxi (<i>Sotalia fluviatilis</i>). Both species have wide geographical ranges and were once considered to be relatively abundant. Their IUCN Red List conservation status of Data Deficient (DD), due to limited information on threats, ecology, population numbers and trends, did not initially cause alarm. However, the development of dolphin hunting to provide fish bait at around the beginning of this millennium broadly coincided with the onset of a widespread perception that numbers of both species were in decline. Consequently, the need for population trend data to inform conservation advice and measures became urgent. This paper presents a 22-year time series of standardised surveys for both dolphins within the Mamirauá Reserve, Amazonas State, Brazil. Analysis of these data show that both species are in steep decline, with their populations halving every 10 years (botos) and 9 years (tucuxis) at current rates. These results are consistent with published, independent information on survival rates of botos in this area, which demonstrated a substantial drop in annual survival, commencing at around the year 2000. Mamirauá is a protected area, and is subject to fewer environmental pressures than elsewhere in the region, so there is no reason to suspect that the decline in dolphins within the Reserve is more pronounced than outside it. If South America's freshwater cetaceans are to avoid following their Asian counterparts on the path to a perilous conservation status, effective conservation measures are required immediately. Enforcement of existing fishery laws would greatly assist in achieving this.</p></div

Não preferência para alimentação em linhagens de meloeiro por mosca-minadora, Liriomyza sativae.

bitstream/item/145341/1/BPD16006.pd

Pregnancy rate in lactating Bos indicus cows subjected to fixed-time artificial insemination and treated with different follicular growth inducers.

The objective of this experiment was to evaluate the effects of replacing eCG with FSH or FSH/LH on the diameter of ovulatory follicles (DOF) and the pregnancy rates (PR) of lactating Bos indicus cows subjected to a synchronization of ovulation protocol and fixed-time artificial insemination (FTAI) based on progesterone, estradiol benzoate (EB), PGF2&#945;, and estradiol cypionate (EC). On day 0, primiparous and multiparous Nellore cows (n = 329) at 68 days postpartum were body condition scored (BCS) and received a P4 implant (PRIMER 1.0 g P4) plus 2 mg EB intramuscularly (IM). At day 8, the implant was removed, and 250 &#956;g cloprostenol were injected IM along with 0.5 mg EC. At the time of implant removal, the animals were divided into one of four treatments: cows received (G1) 1 mL of saline solution IM (Control; n = 80); (G2) 300 IU eCG IM (ECG300; n = 84); (G3) 15 mg FSH IM (Folltropin; n = 82); and (G4) 30 IU FSH/LH IM (Pluset; n = 83); all cows were subjected to FTAI 48-54 h after implant removal (day 10). Transrectal ultrasonography was performed to measure the DOF to FTAI and to estimate the pregnancy rate on day 35. A statistical analysis examined the effects of the treatment, technician, semen, BCS, calf age and parity on PR to FTAI. There was no significant difference in PR and DOF among the treatment groups (G1, 41.3%, 13.1 mm; G2, 46.4%, 14.5 mm; G3, 46.3%, 14.2 mm; and G4, 48.2%, 14.3 mm), but PR was higher in multiparous than in primiparous cows. Commercial FSH solutions (Pluset or Folltropin) do not promote increases in PR or DOF of lactating Nellore cows and are equal to eCG in promoting growth in preovulatory follicles and elevating the PR in Nellore cows with a moderate BCS subjected to a progesterone-based FTAI protocol with EC