排序方式: 共有48条查询结果,搜索用时 15 毫秒
11.
Saran Traoré Mulualem Tigabu Sibiri Jean Ouédraogo Joseph Issaka Boussim Sita Guinko Michel G. Lepage 《Plant Ecology》2008,198(2):285-295
The importance of mounds created by Macrotermes subhyalinus as safe site for tree regeneration was analysed in a savannah woodland of Burkina Faso. Plantlets (height <1.5 m) were sampled
and followed over an year in 72 × 4 m2 quadrats located on M. subhyalinus mounds and adjacent areas. The mechanisms of regeneration and plantlet mortality were also determined. We identified three
regeneration mechanisms: seedlings regenerated by seed (abundant on mounds), sprouts (abundant on adjacent areas) and root
suckers (a rare case on both sites). A total of 37 species representing 17 families and 30 genera were found on all quadrats,
of which 29 species were found on termite mounds and 22 species on adjacent areas. Species richness and density of plantlets
at the 4 m2 scale were higher on mounds than in the adjacent area (P < 0.05). Among plantlet categories, seedling density was significantly different among microhabitats (P < 0.001) and across sampling periods (P < 0.01) and, the majority of plantlet individuals appeared within the 0–25 cm height class. The mortality of plantlets and
particularly seedling mortality differed significantly between microhabitats (P < 0.01) and between periods (P < 0.01), whereas more than half the variation in the death of Acacia erythrocalyx seedlings (the most abundant species) were related to the density of the live seedlings of the same species (P < 0.001). The observed mortality rate was way below 50%; plantlet density remained higher on mound during sampling periods
as compared to the adjacent area. It can thus be concluded that Macrotermes termite mounds are favourable sites for the recruitments of woody plants in savannah woodlands. 相似文献
12.
Martha Ali Abdulai Samuel Afari-Asiedu Daniel Carrion Kenneth Ayuurebobi Ae-Ngibise Stephaney Gyaase Mujtaba Mohammed Oscar Agyei Ellen Boamah-Kaali Theresa Tawiah Rebecca Dwommoh Francis Agbokey Seth Owusu-Agyei Kwaku Poku Asante Darby Jack 《EcoHealth》2018,15(4):757-767
Household air pollution (HAP) is a leading cause of morbidity and mortality worldwide. To limit HAP exposure and environmental degradation from biomass fuel use, the Government of Ghana promotes liquefied petroleum gas (LPG) use in rural Ghana via the Rural LPG program (RLP). We assessed the experiences of the RLP in 2015, 2 years after its launch. A mixed methods approach was used involving Focus Group Discussions (19) and in-depth interviews (25). In addition, a survey questionnaire was administered to elicit socio-demographic characteristics, household cooking practices and stove use patterns of 200 randomly selected respondents. At about 9 months after LPG acquisition,?<?5% of LPG beneficiaries used their stoves. Some of the reasons ascribed to the low usage of the LPG cookstoves were financial constraints, distance to LPG filling point and fear of burns. Community members appreciate the convenience of using LPG. Our results underscore a need for innovative funding mechanisms contextualized within an overall economic empowerment of rural folks to encourage sustained LPG use. It emphasizes the need for innovative accessibility interventions. This could include establishing new LPG filling stations in RLP beneficiary districts to overcome the barriers to sustained LPG use. 相似文献
13.
14.
Issaka Zongo Fabrice A. Somé Serge A. M. Somda Sunil Parikh Noel Rouamba Philip J. Rosenthal Joel Tarning Niklas Lindegardh Fran?ois Nosten Jean Bosco Ouédraogo 《PloS one》2014,9(8)
Background
One promising new Artemisinin-based combination therapies (ACTs) is dihydroartemisinin-piperaquine (DHA-PQ). However, the pharmacokinetics of piperaquine and the relationship between drug levels and clinical efficacy are incompletely characterized, particularly in children.Methods
We performed a single-arm open-label trial in Bobo-Dioulasso, Burkina Faso. A total of 379 participants aged 6 months or more with uncomplicated falciparum malaria were enrolled. Each participant received daily dose of DHA-PQ for three days and followed for 42 days. Parasitological efficacy was analyzed, considering rates of recrudescence and overall recurrence. PK was an exploratory endpoint and a priori, no sample size had been determined. Day 7 capillary and venous plasma concentrations of piperaquine were measured in children aged 2–10 years.Results
Of the 379 participants, 365 (96.3%) completed 42 days of follow-up. The median daily dose of PQ was 18.5 mg/kg [6.5–24]. Treatment with DHA-PQ was well tolerated with fever and parasitemia resolution within 48 hours in nearly all children. Recurrent malaria within 42 days of follow-up occurred in 31.3% (10/34) of children less than 2 years old, 16.0% (16/106) of those aged 2–5 years, 9.4% (15/160) of those aged 5–10 years, and none (0/68) of those over 10 years old. After genotyping, 3 of 41 recurrent episodes were recrudescence. An exploratory analysis shows that children with successful treatment outcomes had significantly higher median plasma concentrations of PQ compared to those with recurrent malaria within 42 days after therapy, considering either capillary samples (68 ng/ml [50–85] compared to 48 ng/ml [36–55], p<0.001) or venous samples (42 ng/ml [29–59] compared to 25 ng/ml [19–44], p<0.001).Conclusion
DHA-PQ was effective for uncomplicated P. falciparum malaria treatment and offers an alternative to other ACTs. Recurrent malaria was mainly due to new infections after treatment and was correlated with low day 7 PQ concentration in the youngest patients.Trial Registration
Controlled-Trials.com ISRCTN59761234 相似文献15.
16.
17.
Systemic lupus erythematosus is a polymorphic and multigenic inflammatory autoimmune disease. Cyclic AMP (cAMP) modulates inflammation and the inhibition of cyclic nucleotide phosphodiesterase type 4 (PDE4), which specifically hydrolyzes cAMP, inhibits TNFα secretion. This study was aimed at investigating the evolution of PDE activity and expression levels during the course of the disease in MRL/lpr lupus-prone mice, and to evaluate in these mice the biological and clinical effects of treatments with pentoxifylline, denbufylline and NCS 613 PDE inhibitors. This study reveals that compared to CBA/J control mice, kidney PDE4 activity of MRL/lpr mice increases with the disease progression. Furthermore, it showed that the most potent and selective PDE4 inhibitor NCS 613 is also the most effective molecule in decreasing proteinuria and increasing survival rate of MRL/lpr mice. NCS 613 is a potent inhibitor, which is more selective for the PDE4C subtype (IC50 = 1.4 nM) than the other subtypes (PDE4A, IC50 = 44 nM; PDE4B, IC50 = 48 nM; and PDE4D, IC50 = 14 nM). Interestingly, its affinity for the High Affinity Rolipram Binding Site is relatively low (Ki = 148 nM) in comparison to rolipram (Ki = 3 nM). Finally, as also observed using MRL/lpr peripheral blood lymphocytes (PBLs), NCS 613 inhibits basal and LPS-induced TNFα secretion from PBLs of lupus patients, suggesting a therapeutic potential of NCS 613 in systemic lupus. This study reveals that PDE4 represent a potential therapeutic target in lupus disease. 相似文献
18.
Jeni Vuong Jean-Marc Collard Melissa J. Whaley Issaka Bassira Issaka Seidou Seydou Diarra Rasmata T. Ouédraogo Dinanibè Kambiré Thomas H. Taylor Jr Claudio Sacchi Leonard W. Mayer Xin Wang 《PloS one》2016,11(2)
Neisseria meningitidis (Nm), Haemophilus influenzae (Hi), and Streptococcus pneumoniae (Sp) are the lead causes of bacterial meningitis. Detection of these pathogens from clinical specimens using traditional real-time PCR (rt-PCR) requires DNA extraction to remove the PCR inhibitors prior to testing, which is time consuming and labor intensive. In this study, five species-specific (Nm-sodC and -ctrA, Hi-hpd#1 and -hpd#3 and Sp-lytA) and six serogroup-specific rt-PCR tests (A, B, C, W, X, Y) targeting Nm capsular genes were evaluated in the two direct rt-PCR methods using PerfeCTa and 5x Omni that do not require DNA extraction. The sensitivity and specify of the two direct rt-PCR methods were compared to TaqMan traditional rt-PCR, the current standard rt-PCR method for the detection of meningitis pathogens. The LLD for all 11 rt-PCR tests ranged from 6,227 to 272,229 CFU/ml for TaqMan, 1,824–135,982 for 5x Omni, and 168–6,836 CFU/ml for PerfeCTa. The diagnostic sensitivity using TaqMan ranged from 89.2%-99.6%, except for NmB-csb, which was 69.7%. For 5x Omni, the sensitivity varied from 67.1% to 99.8%, with three tests below 90%. The sensitivity of these tests using PerfeCTa varied from 89.4% to 99.8%. The specificity ranges of the 11 tests were 98.0–99.9%, 97.5–99.9%, and 92.9–99.9% for TaqMan, 5x Omni, and PerfeCTa, respectively. PerfeCTa direct rt-PCR demonstrated similar or better sensitivity compared to 5x Omni direct rt-PCR or TaqMan traditional rt-PCR. Since the direct rt-PCR method does not require DNA extraction, it reduces the time and cost for processing CSF specimens, increases testing throughput, decreases the risk of cross-contamination, and conserves precious CSF. The direct rt-PCR method will be beneficial to laboratories with high testing volume. 相似文献
19.
Christopher R. Sudfeld Lilia Bliznashka Aichatou Salifou Ousmane Guindo Issaka Soumana Irne Adehossi Cline Langendorf Rebecca F. Grais Sheila Isanaka 《PLoS medicine》2022,19(5)
BackgroundIt is estimated that over 250 million children under 5 years of age in low- and middle-income countries (LMICs) do not reach their full developmental potential. Poor maternal diet, anemia, and micronutrient deficiencies during pregnancy are associated with suboptimal neurodevelopmental outcomes in children. However, the effect of prenatal macronutrient and micronutrient supplementation on child development in LMIC settings remains unclear due to limited evidence from randomized trials.Methods and findingsWe conducted a 3-arm cluster-randomized trial (n = 53 clusters) that evaluated the efficacy of (1) prenatal multiple micronutrient supplementation (MMS; n = 18 clusters) and (2) lipid-based nutrient supplementation (LNS; n = 18 clusters) as compared to (3) routine iron–folic acid (IFA) supplementation (n = 17 clusters) among pregnant women in the rural district of Madarounfa, Niger, from March 2015 to August 2019 (ClinicalTrials.gov identifier ). Children were followed until 2 years of age, and the Bayley Scales of Infant and Toddler Development III (BSID-III) were administered to children every 3 months from 6 to 24 months of age. Maternal report of WHO gross motor milestone achievement was assessed monthly from 3 to 24 months of age. An intention-to-treat analysis was followed. Child BSID-III data were available for 559, 492, and 581 singleton children in the MMS, LNS, and IFA groups, respectively. Child WHO motor milestone data were available for 691, 781, and 753 singleton children in the MMS, LNS, and IFA groups, respectively. Prenatal MMS had no effect on child BSID-III cognitive (standardized mean difference [SMD]: 0.21; 95% CI: −0.20, 0.62; p = 0.32), language (SMD: 0.16; 95% CI: −0.30, 0.61; p = 0.50) or motor scores (SMD: 0.18; 95% CI: −0.39, 0.74; p = 0.54) or on time to achievement of the WHO gross motor milestones as compared to IFA. Prenatal LNS had no effect on child BSID-III cognitive (SMD: 0.17; 95% CI: −0.15, 0.49; p = 0.29), language (SMD: 0.11; 95% CI: −0.22, 0.44; p = 0.53) or motor scores (SMD: −0.04; 95% CI: −0.46, 0.37; p = 0.85) at the 24-month endline visit as compared to IFA. However, the trajectory of BSID-III cognitive scores during the first 2 years of life differed between the groups with children in the LNS group having higher cognitive scores at 18 and 21 months (approximately 0.35 SD) as compared to the IFA group (p-value for difference in trajectory <0.001). Children whose mothers received LNS also had earlier achievement of sitting alone (hazard ratio [HR]: 1.57; 95% CI: 1.10 to 2.24; p = 0.01) and walking alone (1.52; 95% CI: 1.14 to 2.03; p = 0.004) as compared to IFA, but there was no effect on time to achievement of other motor milestones. A limitation of our study is that we assessed child development up to 2 years of age, and, therefore, we may have not captured effects that are easier to detect or emerge at older ages.ConclusionsThere was no benefit of prenatal MMS on child development outcomes up to 2 years of age as compared to IFA. There was evidence of an apparent positive effect of prenatal LNS on cognitive development trajectory and time to achievement of selected gross motor milestones.Trial registrationClinicalTrials.gov NCT02145000.Christopher R. Sudfeld and colleagues evaluate the benefit of multiple micronutrient supplementation and medium‐quantity lipid‐based nutrient supplementation in pregnancy on child development in rural Niger. NCT02145000相似文献
20.
Marcus Beissner Richard Odame Phillips Florian Battke Malkin Bauer Kossi Badziklou Fred Stephen Sarfo Issaka Maman Agata Rhomberg Ebekalisai Piten Michael Frimpong Kristina Lydia Huber Dominik Symank Moritz Jansson Franz Xaver Wiedemann Abiba Banla Kere Karl-Heinz Herbinger Thomas L?scher Gisela Bretzel 《PLoS neglected tropical diseases》2015,9(11)