89 resultados para CHONDRUS-CRISPUS


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Objective: To summarise and critically evaluate the evidence informing the provision of standard care practices and psychosocial interventions following stillbirth. Background: Stillbirth is increasingly recognised as a significant bereavement experience with the potential to cause substantial psychological distress for parents. Standard care practices and psychosocial interventions to support parents have undergone dramatic changes, with limited basis in evidence. Methods: A systematic narrative review was conducted of quantitative studies examining interventions designed to reduce psychological distress in parents following the loss of a stillborn baby. Results: Twenty-five studies met the inclusion criteria for the review. Substantial methodological weaknesses were identified among reviewed studies, including small and heterogeneous loss samples, weak study designs and lack of clarity in reported methods and outcomes. Inadequate replication of many findings substantially limits the generalisability of the evidence. Conclusion: Tentative evidence was found for the provision of mementoes of the baby and information regarding the cause of the loss, support group attendance, and cognitive behavioural interventions for parents identified with clinical levels of distress. Contradictory findings for the impact of contact with the baby prevent the formation of clear conclusions for this practice. Due to the methodological weaknesses prevalent in the research identified, the current evidence base is not considered sufficiently able to reliably inform care practices and intervention approaches. High-quality research evidence in this field is urgently required.

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Determinou-se o efeito do pH na ação de algumas subst âncias promotoras de germinação em sementes de Chenopodium album L., Avena fatua L. e Rumex crispus L. A azida de sódio (A), nitrato de potássio + etileno (NE), NE + A, NE + A + tiuréia + peróxido de hidrogênio foram testados em solo (em bandej as) e em papel (in vitro) com soluções tampão em ambiente controlado. O efeito do NE no estímulo à germinação de sementes não foi afetado pelo pH na faixa de 3 a 9. A azida de sódio foi a substância que mais afetou as sementes, sendo este efeito pH dependente. Este composto foi extremamente deletério em sementes de C. album e A. fatua em solo ácido (pH 4,0), enquanto em solo básico ele estimulou a germinação em sementes de A. fatua, através da superação da dormência A combinação de NE + A em pH 6,2 inibiu a germinação de C. album e A. fatua, mostrando um antagonismo entre estes compostos. A mistura dos cinco compostos reduziu a influência do pH na ação deletéria da azida de sódio. O efeito deletério da azida foi menos afetado pela temperatura do que sua ação como superador de dormência. A solução extraída do solo não afetou a resposta de tratamentos químicos in vitro em diferentes temperaturas comparado a soluções tampão em pH semelhante. Discute-se a influência das características do solo na eficácia de substâncias químicas como superadores de dormência ou tratamentos deletérios às sementes.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Globalization has resulted in unprecedented movements of people, goods, and alien species across the planet. Although the impacts of biological invasions are widely appreciated, a bias exists in research effort to post-dispersal processes because of the difficulties of measuring propagule pressure. The Antarctic provides an ideal model system in which to investigate propagule movements because of the region's isolation and small number of entry routes. Here we investigated the logistics operations of the South African National Antarctic Programme (SANAP) and quantified the initial dispersal of alien species into the region. we found that over 1400 seeds from 99 taxa are transported into the Antarctic each field season in association with SANAP passenger luggage and cargo. The first ever assessment of propagule drop-off indicated that 30-50% of these propagules will enter the recipient environment. Many of the taxa include cosmopolitan weeds and known aliens in the Antarctic, indicating that logistics operations form part of a globally self-perpetuating cycle moving alien species between areas of human disturbance. in addition, propagules of some taxa native to the Antarctic region were also found, suggesting that human movements may be facilitating intra-regional homogenization. Several relatively simple changes in biosecurity policy that could significantly reduce the threat of introduction of nonnative species are suggested.

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New facts on the occurrence and distribution of the threatened and rare stoneworts Chara baltica, C. connivens, C. contraria, C. virgata, Nitella hyalina, N. opaca, N. gracilis, N. capillaris, N translucens and N. flexilis and the non-threatened species Chara globularis in the northwestern part of Lower Saxony (Germany) are presented. A description of the stonewort sites is given and the abundance and the degrees of endangering of the species are discussed. Data about the Vegetation of the habitats of Nitella hyalina and N. opaca are reported. Additionally former sites of Chara canescens have been checked again. References to determination problems concerning Nitella opaca and N flexilis are given. Finally the protection of stoneworts, management requirements and the need for future investigations are discussed.

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In der Döberitzer Heide nördlich von Potsdam wurden vegetationsgeschichtliche Untersuchungen durchgeführt. Das Untersuchungsgebiet befindet sich im östlichen Teil der Nauener Platte, die bisher vegetationsgeschichtlich weitgehend unerforscht war. In sechs verschiedenen Mooren wurden acht Bohrungen niedergebracht. Die Bohrkerne wurden stratigraphisch und pollenanalytisch untersucht und für die Radiocarbondatierung beprobt. Die Pollendiagramme ermöglichen die Rekonstruktion der Vegetationsentwicklung der terrestrischen Standorte und der Moore in der Döberitzer Heide in den letzten 14.000 Jahren. Neben einer Revision der Gliederungsprinzipien der spätglazialen Vegetationsentwicklung Brandenburgs und einer vergleichenden Betrachtung der Moorentwicklung in der Döberitzer Heide wurde besonderes Augenmerk auf die Geschichte des Döberitzer Lindenwaldes gerichtet, der einen Sonderfall in der brandenburgischen Vegetation darstellt. Die Untersuchungen boten die Möglichkeit, die Ursachen seiner Entstehung zu klären, Aussagen zu den Perspektiven seiner Entwicklung zu treffen und mögliche Entwicklungspotentiale von Lindenwäldern im Land Brandenburg aufzuzeigen.

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Lobsigensee is a small kettle hole lake 15 km north-west of Bern on the Swiss Plateau, at an altitude of 514 m asl. Its surface is 2ha today, its maximum depth 2.7 m; it has no inlet and the overflow functions mainly during snow melting. The area was covered by Rhone ice during the Last Glaciation (map in Fig.2). Local geology, climate and vegetation are summarized in Figure 3A-C, the history of settlement in Figures 5-7. In order to reconstruct the vegetational and environmental history of the lake and its surroundings pollen analysis and other bio- and isotope stratigraphies were applied to twelve profiles cored across the basin with modified Livingstone corers (Fig.3 D). (1) The standard diagram: The central core LQ-90 is described as the standard pollen diagram (Chapter 3) with 10 local pollen assemblage zones of the Late-Glacial (local PAZ Ll to Ll0, from about 16'000(7) to 10'000 years BP) and 20 PAZ of the Holocene (local PAZ L11 to L30), see Figs. 8-10 and 20-24. Local PAZ L 1 to L3 are in the Late-Glacial clay and record the vegetational development after the ice retreat: L1 shows very low pollen concentration and high Pinus percentages due to long-distance transport and reworking; the latter mechanism is corroborated by the findings of thermophilous and pre-Quaternary taxa. Local PAZ L2 has a high di versi ty of non-arboreal pollen (NAP) and reflects the Late-Glacial steppe rich in heliophilous species. Local PAZ L3 is similar but additionally rich in Betula nana and Sal1x, thus reflecting a "shrub tundra". The PAZ L1 to L3 belong to the Oldest Dryas biozone. Local PAZ L4 to L 10 are found in the gyttja of the profundal or in the lake marl of the littoral and record the Late-Glacial forests. L4 is the shrub phase of reforestation with very high Junlperus and rapidly increasing Betula percentages. L5 is the PAZ with a first, L7 with a second dominance of tree-birches, separated by L6 showing a depression in the Betula curve. L4 to L7 can be assigned to the Balling biozone. Possible correlation of the Betula depression to the Older Dryas biozone is discussed. In local PAZ L8 Plnus immigrates and expands. L9 shows a facies difference in that Plnus dominates over Betula in littoral but not in profundal spectra. L8 and L9 belong to the Allerod biozone. In its youngest part the volcanic ash from Laach/Eifel is regularly found (11,000 BP). The local PAZ Ll0 corresponds to the Younger Dryas blozone. The merely slight increase of the NAP indicates that the pine forests of the lowland were not strongly affected by a cooler climate. In order to evaluate the significance of the littoral accumulation of coniferous pollen the littoral profile LQ-150 is compared to the profundal. Radiocarbon stratigraphies derived from different materials are presented in Figures 13 and 14 and in Tables 2 and 3. The hard-water errors in the gyttja samples and the carbonate samples are similar. The samples of terrestrial plant macrofossils are not affected by hard-water errors. Two plateaux of constant age appear in the age-depth relationship; their consequence for biostratigraphy as well as pollen concentration and influx diagrams are discussed. Radiocarbon ages of the Late-Glacial pollen zones are shown in Table 10. The Holocene vegetational history is recorded in the local PAZ L 11 to L30. After a Preboreal (PAZ L11) dominated by pine and birch the expansions of Corylus, Ulmus and Quercus are very rapid. Among these taxa Corylus dominates dur ing the Boreal (PAZ L 12 and L 1 3), whereas the components of the mixed oak forest dominate in the Older Atlantic (PAZ L14 to L16). In the Younger Atlantic (PAZ L 17 to L 19) Fagus and Alnus play an increasing, the mixed oak forest a decreasing role. During the period of local PAZ L19 Neolithic settlers lived on the shore of Lobsigensee. During the Subboreal (PAZ L20 and L21) and the Older Subatlantic (L22 to L25) strong fluctuations of Fagus and often antagonistic peaks of NAP, Alnus, Betula and Corylus can be interpreted as signs of human impact on vegetation. L23 is characterized not only by high values of NAP (especially apophytes and anthropochorous species) but also by the appearance of Juglans, Castanea and Secale which point to the Roman colonization of the area. For a certain period during the Younger Subatlantic (PAZ L26 to L30) the lake was used for retting hemp (Cannabis). Later the dominance of Quercus pollen indicates the importance of wood pastures. The youngest sediments reflect the wide-spread agricultural grass lands and the plantation of Pinus and Picea. Radiocarbon dates for the Holocene are given in Figure 23 and Table 4, the extrapolated ages of the Holocene pollen zones in Table 15. (2) The cross sections: Figures 25 and 26 give a summary of the litho- and palynostratigraphy of the two cross sections. Based on 11 Late-Glacial and 9 Holocene pollen diagrams (in addition to the standard ones), the consistency of the criteria for the definition of the pollen zones is examined in Tables 7 and 8 for the Late-Glacial and in Tables 11 to 14 for the Holocene. Sediment thicknesses across the basin for each pollen zone are presented in these tables as well as in Figures 43 to 45 for the Late-Glacial and in Figures 59 to 65 for the Holocene. Sediment focusing can explain differences between the gyttja cores of the profundal. Focusing is more than compensated for through "stretching" by carbonate precipitation on the littoral terrace. Pollen influx to the cross section are discussed (Chapters 4.1.5. and 4.2.3.). (3) The regional pollen zones: Based on some selected sites between Lake Geneva and Lake Constance regional pollen zones are proposed (Table 16, 17 and 19). (4) Paleoecology: Climatic change in the Late-Glacial can be inferred from Coleoptera, Trichoptera, Chironomidae and d18O of carbonates: a distinct warming is recorded around 12' 600 BP and around 10' 000 BP. The Younger Dryas biozone (10'700-10'000 BP) was the only cooling found in the Late-Glacial. The Betula depression often correlated wi th the Older Dryas biozone was possibl not colder but dryer than the previous period. During the Holocene the lowland site is not very sensitive to the minor climatic changes. Table 22 summarizes climatic and trophic changes before 8'000 BP as deduced from various biostratigraphies studied by a number of authors. Ostracods, Chironomids and fossil pigments indicate that anoxic conditions prevailed during the BoIling (possibly meromixis). Changes in the lake level are illustrated in Figure 74. A first lake-level lowering occurred in the early Holocene (10'000 to 9'000 BP), a second during the Atlantic (about 6'800 to 5'200 BP). The first "shrinking" of the lake volume resulted in a eutrophication recorded by laminations in the profundal and by pigments of Cyanophyceae. The second fall in water level corresponds to an increase of Nymphaeaceae. Human impact can be inferred in three ways: eutrophication of the lake (since the Neolithic), changes of terrestrial vegetation by deforestations (cyclicity of Fagus, see Figures 78 to 80), and enhanced erosion (increasing sedimentation rates by inwashed clay, particularly since the Roman Colonization, see Figures 49 and 81). Summary: This paper was planned as the final report on Lobsigensee. However, a number of issues are not answered but can only be asked more precisely, for example: (1) For the two periods with the highest rates of change, Le. the Bolling and the Preboreal biozones, pollen influx may reflect vegetation dynamics. Detailed investigations of these periods in annually laminated sediments are planned. (2) Biostratigraphies other than palynostratigraphy are needed to estimate the degree of linkage or independence in the development of terrestrial and lacustrine ecosystems. Often our sampling intervals were not identical, thus influencing our temporal resolution. (3) 6180- and 14C-stratigraPhies with high resolution will elucidate the leads and lags of these dynamic periods. Plateaux of constant age in the age-depth relationship have a strong bearing on both biological and geophysical understanding of Late-Glacial and early Holocene developments. (4) Numerical methods applied to the pollen diagrams of the cross section will help to quantify the significance of similari ties and dissimilarities across a single basin (with Prof. Birks). (5) Numerical methods applied to different sites on the Swiss Plateau and on the transect across the Alps will be helpful in evaluating the influence of different environmental factors (with Prof. Birks). (6) A new map 1: 1000 with 50cm-contour lines prov ided by Prof. Zurbuchen will be combined with a grid of cores sampling the transition from lake marl to peat enabling us to calculate paleo-volumes of the lake. This is interesting for the two "shrinking periods" (in Fig. 74A numbers 2-6 and 7-10), both accompanied by eutrophication. The pal eo-volume during the Neoli thic set tlement of the Cortaillod culture linked wi th an est l.mate of trophic change derived from diatoms (Prof. Smol in prep.) could possibly give an indication of the size of the human population of this period. (7) For the period with the antagonism between Fagus peaks and ABC-peaks close collaboration between palynologists, geochemists and archeologists should enable us to determine the influence of prehistoric and historic people on vegetation (collaboration with Prof. Stockli and Prof. Herzig). (8) The core LL-75 taken with a "cold letter box" will be analysed for major and trace elements by Dr. Sturm for 210pb and 137Cs by Prof.von Gunten and for pollen. We will see if our local PAZ L30 really corresponds to the surface sediment and if the small seepage lake reflects modern pollution.