Assessment of post-burn removal methods for Acacia saligna in Cape Flats Sand Fynbos, with consideration of indigenous plant recovery

The Greater Cape Floristic Region (GCFR) of South Africa is a biodiversity hotspot threatened by the impacts of habitat transformation and invasive alien species. Cape Flats Sand Fynbos (CFSF) is a critically endangered vegetation type occurring within the GCFR, and its largest remaining fragment is the focus of a large-scale invasive plant control and biodiversity restoration project. Acacia saligna is a highly problematic invasive in CFSF and the main target of the control. To mitigate damage caused by this species, stands are removed and burned, which stimulates both the large invasive seed-bank and the indigenous seed-bank in the soil. Although there are no clear methods on how to manage the re-invasion at this stage without damaging indigenous plant recovery, three post-burn removal methods have the potential to be effective: (1) cutting the Acacia saplings below the coppicing point, (2) cutting the saplings and applying herbicide to the stumps, and (3) foliar herbicide spray. The aims of this studywere to (i) find the most effective post-burn A. saligna control treatment, (ii) find the treatment that causes the least harm to indigenous plant recovery, (iii) determine the most cost-effective treatment, and (iv) establish which treatment is the most suitable for large-scale use. Cutting below the coppicing point of the A. saligna provided the most effective removal and was also the least damaging to indigenous vegetation recovery. The foliar spray treatment, however, saved the most time and costs. The best method is therefore dependent on the project goals, scale, and density of the A. saligna invasion. These results may be applicable to other types of fynbos and to other fire-stimulated invasive Acacia species

Decoherence-Free Quantum Information Processing with Four-Photon Entangled States

Decoherence-free states protect quantum information from collective noise, the predominant cause of decoherence in current implementations of quantum communication and computation. Here we demonstrate that spontaneous parametric down-conversion can be used to generate four-photon states which enable the encoding of one qubit in a decoherence-free subspace. The immunity against noise is verified by quantum state tomography of the encoded qubit. We show that particular states of the encoded qubit can be distinguished by local measurements on the four photons only.Comment: 4 pages, 4 eps figures, revtex

Observations of the Sunyaev-Zel'dovich effect at high angular resolution towards the galaxy clusters A665, A2163 and CL0016+16

We report on the first observation of the Sunyaev-Zel'dovich effect with the Diabolo experiment at the IRAM 30 metre telescope. A significant brightness decrement is detected in the direction of three clusters (Abell 665, Abell 2163 and CL0016+16). With a 30 arcsecond beam and 3 arcminute beamthrow, this is the highest angular resolution observation to date of the SZ effect.Comment: 23 pages, 8 figures, 6 tables, accepted to New Astronom

Análise de nutrientes em mudas de Nó-de-Cachorro (Heteropterys aphrodisiaca O. Mach.) cultivadas em diferentes substratos.

A espécie Heteropterys aphrodisíaca O. Mach (Nó -de-cachorro) é tida como planta medicinal de grande importância devido as suas atribuições curativas de enfermidades. Contudo, a parte fitotécnica ainda é pouco estudada. O objetivo do trabalho foi analisar os teores de sódio (Na), potássio (K), fósforo (P), magnésio (Mg), cálcio (Ca), manganês (Mn), ferro (Fe), nitrogênio total (NT) e proteína bruta (PB) nas folhas de mudas de Heteropterys aphrodisíaca O. Mach sob quatro tipos de misturas (M) contendo diferentes proporções de terra e areia e duas profundidades (P) de semeadura.bitstream/CPAP/55781/1/BP72.pdfBoletim de Pesquisa e Desenvolvimento Formato Eletrônico

A framework for the standardisation of tropical tuna purse seine CPUE: application to the yellowfin tuna in the Indian Ocean

We revised the existing framework for tuna CPUE standardisation in light of the increasing literature that advocates the use of mixed effects models to account for the characteristics of logbook data. We apply the framework on yellowfin tuna (YFT) from the Indian Ocean, caught by the purse seine EU fleet (Spain and France) from 1984 to 2015. We used a comprehensive list of candidate covariates, including non- conventional covariates, and run exploratory models to assess the contribution of each covariate. Due to the large number of covariates, the lasso – least absolute shrinkage and selection operator- method was applied for data mining and model selection purposes. The results are two standardised YFT CPUE time series for the period 1984-2015, one for large fish caught in free-school related sets, and one for mainly juveniles caught in floating object related sets. Issues on the usefulness of highly aggregated data (low resolution: annual and fleet wide) is discussed along with the need for more detailed information on the use of dFADs, preferably at the level of a fishing trip.Preprin