303 research outputs found

    Studies on the seedling growth of Adansonia digitata AL.

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    The germination and growth of seedlings of Adansonia digitata were investigated at the Biological garden of ABU Zaria, Nigeria (07o38′ and 11o11′N) at different planting depths and soil types. The seeds were planted at different planting depths of 1.0 cm, 2.0 cm, 4.0 cm and 6.0 cm in nursery bags and kept in a screen house and watered regularly. Results shows that as the planting depth increased, there was an increase in percentage germination, seedling height, number of leaves produced and leaf area index. The case was reverse in terms of percentage survival as increased planting depth resulted in a decrease survival. Number of days before emergence increased with increased planting depth. The highest percentage germination was recorded in sandy soil (75 %), followed by humus soil (32.7 %) while clay soil had no germination. The highest number of days before emergence was recorded in humus soil. Sandy soil had seedlings that produced leaves with Leaf Area Index (LAI) of 18.04 cm2, Humus 9.24 cm2 and loamy soil 7.26 cm2. All seedlings from all soil types produced between 8-15 leaves. Germinated seedlings from clay soil did not survive 60 days post planting. Significant correlation values were observed between planting depth and seedling height, number of days before emergence, number of leaves produced and seedling survival. Both the depth of planting and soil type affected seed germination and seedling performance of Adansonia digitata. Keywords: Planting depth, soil type, seed, germination, seedling, Adansonia digitat

    The effect of seed mass and cotyledon removal on the germination and growth of fluted pumpkin (telfaria occidentalis hook. F)

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    Experiments were carried out to determine the effect of seed mass and cotyledon removal on the germination and growth of African fluted pumpkin (Telfaria occidentalis, Hook. F.). The seeds of pumpkin were divided into 3 weight classes A (13.10-13.05 g), B (11.10-11.05 g), C (8.60-8.55 g) and planted in a 1:1 mixture of soil and sawdust, and the following parameters observed: germination rate, seedling height, number of leaves produced, leaf area index, fresh and dry weight of seedlings. Except for leaf area index, it was found that the seeds with the highest weight showed superiority over the seeds of the other weight classes based on the results of Analysis of variance (ANOVA) at P> 0.05. The removal of one and two cotyledons had adverse effect on the seedling growth. The plants with their two cotyledons removed both before and after first foliage leaves emergence showed the least seedling growth. The seed mass was strongly positively correlated with the observed parameters. These results show that seedlings originating from large seeds can better endure loss of cotyledons and aerial biomass and are thus better adapted to withstand cotyledon damage due to soil fauna and other deteriorating factors in the early stage of life

    Methodological Guide to Co-design Climate-smart Options with Family Farmers

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    Climate-smart agriculture (CSA) seeks to improve productivity for the achievement of food security (pillar 1: Productivity), to develop a better ability to adapt (pillar 2: Adaptation), and to limit greenhouse gas emissions (pillar 3: Mitigation). Technical and organizational innovations are needed to find synergies among those three pillars. Innovation (its creation and its operation) is a social phenomenon. Many studies worldwide have shown that promoting a sustainable change and innovation within organizations has to be analyzed and implemented with stakeholders. Thus, the ability of local actors to tackle climate change and mitigate its effects will depend on their ability to innovate and mobilize material and non-material resources, to articulate links among national policies, not only between themselves, but also undertaking actions at the local level. To support stakeholders in the development of responses to this challenge, we propose the development of open innovation platforms, in which all local actors may participate. These platforms are virtual, physical, or physico-virtual spaces to learn, jointly conceive, and transform different situations; they are generated by individuals with different origins, different backgrounds and interests (Pali and Swaans, 2013).The purpose of this manual is to provide a seven-step methodology to allow family farmers to co-build and adopt CSA options to tackle climate change in an open innovation platfor

    Background Independent Quantum Mechanics and Gravity

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    We argue that the demand of background independence in a quantum theory of gravity calls for an extension of standard geometric quantum mechanics. We discuss a possible kinematical and dynamical generalization of the latter by way of a quantum covariance of the state space. Specifically, we apply our scheme to the problem of a background independent formulation of Matrix Theory.Comment: 9 pages, LaTe

    Human Perivascular Stem Cells Show Enhanced Osteogenesis and Vasculogenesis with Nel-Like Molecule I Protein

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    An ideal mesenchymal stem cell (MSC) source for bone tissue engineering has yet to be identified. Such an MSC population would be easily harvested in abundance, with minimal morbidity and with high purity. Our laboratories have identified perivascular stem cells (PSCs) as a candidate cell source. PSCs are readily isolatable through fluorescent-activated cell sorting from adipose tissue and have been previously shown to be indistinguishable from MSCs in the phenotype and differentiation potential. PSCs consist of two distinct cell populations: (1) pericytes (CD146+, CD34−, and CD45−), which surround capillaries and microvessels, and (2) adventitial cells (CD146−, CD34+, and CD45−), found within the tunica adventitia of large arteries and veins. We previously demonstrated the osteogenic potential of pericytes by examining pericytes derived from the human fetal pancreas, and illustrated their in vivo trophic and angiogenic effects. In the present study, we used an intramuscular ectopic bone model to develop the translational potential of our original findings using PSCs (as a combination of pericytes and adventitial cells) from human white adipose tissue. We evaluated human PSC (hPSC)-mediated bone formation and vascularization in vivo. We also examined the effects of hPSCs when combined with the novel craniosynostosis-associated protein, Nel-like molecule I (NELL-1). Implants consisting of the demineralized bone matrix putty combined with NELL-1 (3 μg/μL), hPSC (2.5×10(5) cells), or hPSC+NELL-1, were inserted in the bicep femoris of SCID mice. Bone growth was evaluated using microcomputed tomography, histology, and immunohistochemistry over 4 weeks. Results demonstrated the osteogenic potential of hPSCs and the additive effect of hPSC+NELL-1 on bone formation and vasculogenesis. Comparable osteogenesis was observed with NELL-1 as compared to the more commonly used bone morphogenetic protein-2. Next, hPSCs induced greater implant vascularization than the unsorted stromal vascular fraction from patient-matched samples. Finally, we observed an additive effect on implant vascularization with hPSC+NELL-1 by histomorphometry and immunohistochemistry, accompanied by in vitro elaboration of vasculogenic growth factors. These findings hold significant implications for the cell/protein combination therapy hPSC+NELL-1 in the development of strategies for vascularized bone regeneration

    The Nell-1 Growth Factor Stimulates Bone Formation by Purified Human Perivascular Cells

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    The search for novel sources of stem cells other than bone marrow mesenchymal stem cells (MSCs) for bone regeneration and repair has been a critical endeavor. We previously established an effective protocol to homogeneously purify human pericytes from multiple fetal and adult tissues, including adipose, bone marrow, skeletal muscle, and pancreas, and identified pericytes as a primitive origin of human MSCs. In the present study, we further characterized the osteogenic potential of purified human pericytes combined with a novel osteoinductive growth factor, Nell-1. Purified pericytes grown on either standard culture ware or human cancellous bone chip (hCBC) scaffolds exhibited robust osteogenic differentiation in vitro. Using a nude mouse muscle pouch model, pericytes formed significant new bone in vivo as compared to scaffold alone (hCBC). Moreover, Nell-1 significantly increased pericyte osteogenic differentiation, both in vitro and in vivo. Interestingly, Nell-1 significantly induced pericyte proliferation and was observed to have pro-angiogenic effects, both in vitro and in vivo. These studies suggest that pericytes are a potential new cell source for future efforts in skeletal regenerative medicine, and that Nell-1 is a candidate growth factor able to induce pericyte osteogenic differentiation

    Potential causal association between gut microbiome and posttraumatic stress disorder

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    Background: The causal effects of gut microbiome and the development of posttraumatic stress disorder (PTSD) are still unknown. This study aimed to clarify their potential causal association using mendelian randomization (MR). Methods: The summary-level statistics for gut microbiome were retrieved from a genome-wide association study (GWAS) of the MiBioGen consortium. As to PTSD, the Freeze 2 datasets were originated from the Psychiatric Genomics Consortium Posttraumatic Stress Disorder Working Group (PGC-PTSD), and the replicated datasets were obtained from FinnGen consortium. Single nucleotide polymorphisms meeting MR assumptions were selected as instrumental variables. The inverse variance weighting (IVW) method was employed as the main approach, supplemented by sensitivity analyses to evaluate potential pleiotropy and heterogeneity and ensure the robustness of the MR results. We also performed reverse MR analyses to explore PTSD’s causal effects on the relative abundances of specific features of the gut microbiome. Results: In Freeze 2 datasets from PGC-PTSD, eight bacterial traits revealed a potential causal association between gut microbiome and PTSD (IVW, all P < 0.05). In addition, Genus.Dorea and genus.Sellimonas were replicated in FinnGen datasets, in which eight bacterial traits revealed a potential causal association between gut microbiome and the occurrence of PTSD. The heterogeneity and pleiotropy analyses further supported the robustness of the IVW findings, providing additional evidence for their reliability. Conclusion: Our study provides the potential causal impact of gut microbiomes on the development of PTSD, shedding new light on the understanding of the dysfunctional gut-brain axis in this disorder. Our findings present novel evidence and call for investigations to confirm the association between their links, as well as to illuminate the underlying mechanisms

    Assessment of variation in immunosuppressive pathway genes reveals TGFBR2 to be associated with prognosis of estrogen receptor-negative breast cancer after chemotherapy

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    Introduction: Tumor lymphocyte infiltration is associated with clinical response to chemotherapy in estrogen receptor (ER) negative breast cancer. To identify variants in immunosuppressive pathway genes associated with prognosis after adjuvant chemotherapy for ER-negative patients, we studied stage I-III invasive breast cancer patients of European ancestry, including 9,334 ER-positive (3,151 treated with chemotherapy) and 2,334 ER-negative patients (1,499 treated with chemotherapy). Methods: We pooled data from sixteen studies from the Breast Cancer Association Consortium (BCAC), and employed two independent studies for replications. Overall 3,610 single nucleotide polymorphisms (SNPs) in 133 genes were genotyped as part of the Collaborative Oncological Gene-environment Study, in which phenotype and clinical data were collected and harmonized. Multivariable Cox proportional hazard regression was used to assess genetic associations with overall survival (OS) and breast
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