101 research outputs found

    The effect of hydrogen cyanamide on bud break and yield of kiwifruit in Northwest-Portugal

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    Kiwifruit (Actinidia deliciosa cv. Hayward) was introduced into Northwest Portugal at the early 1970's increasing its importance up to date. The main objective of orchard management is to find out the cultural techniques suitable for the region, in order to obtain good yield and quality fruit. Winter chilling (less than or equal to7.2degreesC) plays a significant role in kiwifruit break dormancy. Insufficient chilling can be countered by chemical agents as hydrogen cyanamid (Dormex). The objective of this research was to quantify the efficiency of hydrogen cyanamide (0%, 4%, and 6%) on bud break dormancy and yield and fruit quality. Experiments were carried out over two years on a mature 'Hayward' kiwifruit orchard. The results showed that 4% Dormex was the most efficient in increasing marketable yield due to increase of flower bud formation and higher level of fruit set. There were no significant differences among treatments in soluble solids content, flesh firmness and dry weight. Titrable acidity showed higher values with increased Dormex concentration

    Evaluation of the effect of complementary pollination on Actinidia deliciosa 'Hayward' in northwest Portugal

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    The objective of this research was to study the effect of complementary pollination on kiwifruit production and quality. For 3 years, complementary application of wet or dry pollen have been done at different stages of flower opening on vines in the Portuguese regions of Entre-Douro e Minho and Beira Litoral. Commercial production data were collected and fruit quality attributes were measured at harvest. Complementary pollination did not affect fruit soluble solids content or firmness in any year, and was beneficial for fruit size and commercial production in the third year only, showing that it is important in some conditions, when natural pollination is inadequate

    A biomechanical perspective on perineal injuries during childbirth

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    Background and objective: Childbirth trauma is a major health concern that affects millions of women worldwide. Severe degrees of perineal trauma, designated as obstetric anal sphincter injuries (OASIS), and levator ani muscle (LAM) injuries are associated with long-term morbidity. While significant research has been conducted on LAM avulsions, less attention has been given to perineal trauma and OASIS, which affect up to 90% and 11% of vaginal deliveries, respectively. Despite being widely discussed, childbirth trauma remains unpredictable. This work aims to enhance the modeling of the maternal musculature during childbirth, with a particular focus on understanding the mechanisms underlying the often overlooked perineal injuries. Methods: A geometrical model of the pelvic floor muscles (PFM) and perineum (including the perineal body, ischiocavernosus, bulbospongiosus, superficial and deep transverse perineal muscles) was created. The muscles were characterized by a transversely isotropic visco-hyperelastic constitutive model. Two simulations of vaginal delivery were conducted with the fetus in the vertex presentation and occipito-anterior position, with and without the perineum. Results: The simulation that considered the perineum exhibited higher stresses over an extended area of the PFM, which suggests that including additional structures can impact the obtained results. The maximum stretch of the urogenital hiatus was 2.94 and the maximum stress was 23.86 kPa. The perineal body reached a maximum stretch of 1.95, which was more pronounced near the urogenital hiatus, where perineal tears may occur. The external anal sphincter's transverse diameter decreased by 51% and the maximum principal stresses were observed in the area close to the perineal body, where OASIS can occur. Conclusions: The present study emphasizes the importance of including most structures involved in vaginal delivery in its biomechanical analysis and represents another step further in the understanding of perineal injuries and OASIS. The superior region of the perineal body and its connection to the urogenital hiatus and anal sphincter have been identified as the most critical regions, highly susceptible to injury

    Molecular detection of EGFRvIII-positive cells in the peripheral blood of breast cancer patients

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    The aim of this study is to evaluate epidermal growth factor receptor variant III, EGFRvIII, a cancer specific mutant, as a possible marker for the diagnosis of breast cancer occult systemic disease. EGFRvIII mRNA was identified by an RT-nested PCR with a high sensitivity. In 102 women studied, the mutant was detected in the peripheral blood of 30% of 33 low risk, early stage patients, in 56% of 18 patients selected for neoadjuvant chemotherapy, in 63.6% of 11 patients with disseminated disease and 0% of 40 control women. In low risk, early stage patients, the presence of one or more tumour characteristics predicting recurrence such as the absence of oestrogen receptors and the presence of ERBB2 or histologic grades G2/G3 was significantly associated with EFGRvIII detection (p < 0.05). EGFRvIII mRNA has characteristics to be a useful marker for the diagnosis of occult systemic disease in breast cancer. Follow-up studies will evaluate its clinical value as a decision criterion for systemic therapy.http://www.sciencedirect.com/science/article/B6T68-4KV2RH2-1/1/8d7f06700e09e0cb34c8a3861e1b0ba

    Control mechanisms of primary productivity revealed by Calcareous Nannoplankton from marine isotope stages 12 to 9 at the Shackleton Site (IODP Site U1385)

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    Nowadays, primary productivity variations at the SW Iberian Margin (IbM) are primarily controlled by wind-driven upwelling. Thus, major changes in atmospheric circulation and wind regimes between the Marine Isotope Stages (MIS) 12 and 9 could have driven substantial changes in phytoplankton productivity which remains poorly understood. We present a high-resolution calcareous nannofossil record from the Shackleton Site Integrated Ocean Discovery Program Site U1385 that allow the assessment of primary productivity and changing surface conditions on orbital and suborbital timescales over the SW IbM. These records are directly compared and integrated with terrestrial – Mediterranean forest pollen – and marine – benthic and planktic oxygen stable isotopes (δ18O), alkenone concentration [C37], Uk´37-Sea Surface Temperature and % C37:4 – proxy records from Site U1385. Our results indicate intra-interglacial increase in primary productivity together with intensification of the Azores anticyclonic high-pressure cell beyond the summer that suggests a two-phase upwelling behavior during the full interglacial MIS 11c (420–397ka), potentially drived by atmospheric NAO-like variability. Primary productivity is largely enhanced during the inception of glacial MIS 10 and the early MIS 10 (392–356ka), linked to intensified upwelling and associated processes during a period of strengthened atmospheric circulation. In agreement with the conditions observed during Heinrich events of the last glacial cycle, primary productivity reductions during abrupt cold episodes, including the Heinrich-type (Ht) events 4 to 1 (436, 392, 384 and 339ka) and the Terminations V and IV, seems to be the result of halocline formation induced by meltwater arrival, reducing the regional upward nutrient transferenceFPU17/03349, PTDC/CTA-GEO/29897/2017, UIDB/04326/2020, UIDB/04326/2020, CEECIND/02208/2017info:eu-repo/semantics/publishedVersio

    Evaluation of mutagenicity and antimutagenicity of different fractions of Pterogyne nitens (Leguminosae), using Tradescantia pallida micronuclei assay

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    Pterogyne nitens (Fabaceae-Caesalpinioideae) é uma árvore nativa da América do Sul, onde é empregada na medicina popular para o tratamento da ascaridíase. Recentemente, descrevemos o efeito mutagênico do extrato etanólico das folhas de P. nitens. Dessa forma, o presente estudo teve por objetivo aprofundar a avaliação do potencial mutagênico das frações isoladas das folhas de Pterogyne nitens, acetato de etila (AcOEt), n-butanólica (BuOH) e hidroalcóolica (HA). Quando o efeito mutagênico foi observado somente nas maiores concentrações testadas, o potencial antimutagênico também foi avaliado. Os ensaios mutagênicos e antimutagênicos foram realizados utilizando ensaio de micronúcleo em Trandescantia pallida. Na avaliação de mutagenicidade, observou-se o efeito nas frações AcOEt (0,460 mg/mL), BuOH (0,142, 0,285, 0,570 e 1,14 mg/mL) e HA (0,050, 0,100, 0,200 e 0,400 mg/mL). Considerando que o efeito mutagênico da fração AcOEt foi observado somente na concentração mais elevada (0,460 mg/mL), o potencial antimutagênico da mesma foi avaliado. As concentrações de 0,115 e 0,230 mg/mL da fração AcOEt demonstraram atividade antimutagênica. A partir dos resultados do presente estudo, conclui-se que determinadas frações de P. nitens apresentam mutagenicidade (BuOH e HA), enquanto a fração AcOEt apresentou efeito antimutagênico nas maiores concentrações. Esses resultados tornam o estudo da P. nitens bastante promissor, considerando que esta planta possui distribuição geográfica ampla e tem sido pouco estudada.Pterogyne nitens (Fabaceae-Caesalpinioideae) is a tree native to South American, where it is used in folk treatment of ascaridiasis. Recently, we have been describing the mutagenic effect of the ethanol extract of leaves of P. nitens. Thus, the present study aimed at evaluating the mutagenic potential of the ethyl acetate (EtOAc), n- butanol (BuOH) and hydroalcoholic (HA) fractions. When the mutagenic effect was observed only in the highest tested concentrations, the antimutagenic activity was also evaluated. Both mutagenic and antimutagenic assays were performed using T. pallida micronuclei assay. Mutagenicity was observed between different concentrations of the P nitens fractions, EtOAc (0.460 mg/mL), BuOH (0.142, 0.285, 0.570 and 1.14 mg/mL) and HA (0.050, 0.100, 0.200 and 0.400 mg/mL). Whereas the mutagenic effect of the EtOAc fraction was observed in the highest concentration (0.460 mg/mL), its antimutagenic potential was evaluated. The 0.115 and 0.230 mg/mL concentrations of the EtOAc fraction demonstrated antimutagenic activity. Based on the results of the present study we can conclude that some P. nitens fractions (BuOH and HA) demonstrated mutagenic effects whereas the EtOAc fraction shown low mutagenicity and amtimutagenicity in the two higher concentrations. Those results stimulate the studies with P. nitens, which possess spread geographic distribution and it is still low studied

    Efficacy of a broad host range lytic bacteriophage against E. coli adhered to urothelium

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    Persistent urinary tract infections (UTI) are often caused by E. coli adhered to urothelium. This type of cells is generally recognized as very tolerant to antibiotics which renders difficult the treatment of chronic UTI. This work investigates the use of lytic bacteriophages as alternative antimicrobial agents, particularly the interaction of phages with E. coli adhered to urothelium and specifically determines their efficiency against this type of cells. The bacterial adhesion to urothelium was performed varying the bacterial cell concentrations and the period and conditions (static, shaken) of adhesion. Three collection bacteriophages (T1, T4 and phiX174 like phages) were tested against clinical E. coli isolates and only one was selected for further infection experiments. Based on the lytic spectrum against clinical isolates and its ability to infect the highest number of antibiotic resistant strains, the T1-like bacteriophage was selected. This bacteriophage caused nearly a 45 % reduction of the bacterial population after 2 h of treatment. This study provides evidence that bacteriophages are effective in controlling suspended and adhered cells and therefore can be a viable alternative to antibiotics to control urothelium adhered bacteria

    Unraveling the forcings controlling the vegetation and climate of the best orbital analogues for the present interglacial in SW Europe

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    The suitability of MIS 11c and MIS 19c as analogues of our present interglacial and its natural evolution is still debated. Here we examine the regional expression of the Holocene and its orbital analogues over SW Iberia using a model-data comparison approach. Regional tree fraction and climate based on snapshot and transient experiments using the LOVECLIM model are evaluated against the terrestrial-marine profiles from Site U1385 documenting the regional vegetation and climatic changes. The pollen-based reconstructions show a larger forest optimum during the Holocene compared to MIS 11c and MIS 19c, putting into question their analogy in SW Europe. Pollen-based and model results indicate reduced MIS 11c forest cover compared to the Holocene primarily driven by lower winter precipitation, which is critical for Mediterranean forest development. Decreased precipitation was possibly induced by the amplified MIS 11c latitudinal insolation and temperature gradient that shifted the westerlies northwards. In contrast, the reconstructed lower forest optimum at MIS 19c is not reproduced by the simulations probably due to the lack of Eurasian ice sheets and its related feedbacks in the model. Transient experiments with time-varying insolation and CO2 reveal that the SW Iberian forest dynamics over the interglacials are mostly coupled to changes in winter precipitation mainly controlled by precession, CO2 playing a negligible role. Model simulations reproduce the observed persistent vegetation changes at millennial time scales in SW Iberia and the strong forest reductions marking the end of the interglacial "optimum".SFRH/BD/9079/2012, SFRH/BPD/108712/2015, SFRH/BPD/108600/2015info:eu-repo/semantics/publishedVersio
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