124 research outputs found
Conceptualising the hydrology of tropical wetlands to aid habitat management in northern Zambia
Aflatoxin biocontrol effectiveness in the real world-Private sector-led efforts to manage aflatoxins in Nigeria through biocontrol-centered strategies
Open Access Journal; Published online: 02 Sep 2022Aflatoxins are toxic compounds produced by several Aspergillus species that contaminate various crops. The impact of aflatoxin on the health of humans and livestock is a concern across the globe. Income, trade, and development sectors are affected as well. There are several technologies to prevent aflatoxin
contamination but there are difficulties in having farmers use them. In Nigeria, an aflatoxin biocontrol product containing atoxigenic isolates of A. flavus has been registered with regulatory authorities and is now being produced at scale by the private company Harvestfield Industries Limited (HIL). The current study reports results of biocontrol effectiveness trials in maize conducted by HIL during 2020 in several locations across Nigeria and compared to untreated maize from nearby locations. Also, maize was collected from open markets to assess levels of contamination. All treated maize met tolerance thresholds
(i.e., <4 ppb total aflatoxin). In contrast, most maize from untreated fields had a higher risk of aflatoxin contamination, with some areas averaging 38.5 ppb total aflatoxin. Maize from open markets had aflatoxin above tolerance thresholds with even an average of up to 90.3 ppb. Results from the trials were presented
in a National Workshop attended by key officers of Government agencies, farmer organizations, the private sector, NGOs, and donors. Overall, we report (i) efforts spearheaded by the private sector to have aflatoxin management strategies used at scale in Nigeria, and (ii) deliberations of key stakeholders to ensure the safety of crops produced in Nigeria for the benefit of farmers, consumers, and industries
Postpartum maternal morbidity requiring hospital admission in Lusaka, Zambia â a descriptive study
BACKGROUND: Information on the extent of postpartum maternal morbidity in developing countries is extremely limited. In many settings, data from hospital-based studies is hard to interpret because of the small proportion of women that have access to medical care. However, in those areas with good uptake of health care, the measurement of the type and incidence of complications severe enough to require hospitalisation may provide useful baseline information on the acute and severe morbidity that women experience in the early weeks following childbirth. An analysis of health services data from Lusaka, Zambia, is presented. METHODS: Six-month retrospective review of hospital registers and 4-week cross-sectional study with prospective identification of postpartum admissions. RESULTS: Both parts of the study identified puerperal sepsis and malaria as, respectively, the leading direct and indirect causes of postpartum morbidity requiring hospital admission. Puerperal sepsis accounted for 34.8% of 365 postpartum admissions in the 6-month period. Malaria and pneumonia together accounted for one-fifth of all postpartum admissions (14.5% & 6% respectively). At least 1.7% of the postpartum population in Lusaka will require hospital-level care for a maternal morbidity. CONCLUSIONS: In developing country urban settings with high public health care usage, meticulous review of hospital registers can provide baseline information on the burden of moderate-to-severe postpartum morbidity
Does community-based distribution of HIV self-tests increase uptake of HIV testing? Results of pair-matched cluster randomised trial in Zambia.
OBJECTIVES: Ending HIV by 2030 is a global priority. Achieving this requires alternative HIV testing strategies, such as HIV self-testing (HIVST) to reach all individuals with HIV testing services (HTS). We present the results of a trial evaluating the impact of community-based distribution of HIVST in community and facility settings on the uptake of HTS in rural and urban Zambia. DESIGN: Pair-matched cluster randomised trial. METHODS: In catchment areas of government health facilities, OraQuick HIVST kits were distributed by community-based distributors (CBDs) over 12 months in 2016-2017. Within matched pairs, clusters were randomised to receive the HIVST intervention or standard of care (SOC). Individuals aged â„16 years were eligible for HIVST. Within communities, CBDs offered HIVST in high traffic areas, door to door and at healthcare facilities. The primary outcome was self-reported recent testing within the previous 12 months measured using a population-based survey. RESULTS: In six intervention clusters (population 148 541), 60 CBDs distributed 65 585 HIVST kits. A recent test was reported by 66% (1622/2465) in the intervention arm compared with 60% (1456/2429) in SOC arm (adjusted risk ratio 1.08, 95%âCI 0.94 to 1.24; p=0.15). Uptake of the HIVST intervention was low: 24% of respondents in the intervention arm (585/2493) used an HIVST kit in the previous 12 months. No social harms were identified during implementation. CONCLUSION: Despite distributing a large number of HIVST kits, we found no evidence that this community-based HIVST distribution intervention increased HTS uptake. Other models of HIVST distribution, including secondary distribution and community-designed distribution models, provide alternative strategies to reach target populations. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Registry (NCT02793804)
Consistent, small effects of treefall disturbances on the composition and diversity of four Amazonian forests
Summary 1. Understanding the resilience of moist tropical forests to treefall disturbance events is important for understanding the mechanisms that underlie species coexistence and for predicting the future composition of these ecosystems. Here, we test whether variation in the functional composition of Amazonian forests determines their resilience to disturbance. 2. We studied the legacy of natural treefall disturbance events in four forests across Amazonia that differ substantially in functional composition. We compared the composition and diversity of all free-standing woody stems 2-10 cm diameter in previously disturbed and undisturbed 20 9 20 m subplots within 55, one-hectare, long-term forest inventory plots. 3. Overall, stem number increased following disturbance, and species and functional composition shifted to favour light-wooded, small-seeded taxa. Alpha-diversity increased, but beta-diversity was unaffected by disturbance, in all four forests. 4. Changes in response to disturbance in both functional composition and alpha-diversity were, however, small (2 -4% depending on the parameter) and similar among forests. 5. Synthesis. This study demonstrates that variation in the functional composition of Amazonian forests does not lead to large differences in the response of these forests to treefall disturbances, and overall, these events have a minor role in maintaining the diversity of these ecosystems
Basin-wide variation in tree hydraulic safety margins predicts the carbon balance of Amazon forests
Tropical forests face increasing climate risk1,2, yet our ability to predict their response to climate change is limited by poor understanding of their resistance to water stress. Although xylem embolism resistance thresholds (for example, Κ50) and hydraulic safety margins (for example, HSM50) are important predictors of drought-induced mortality risk3â5, little is known about how these vary across Earthâs largest tropical forest. Here, we present a pan-Amazon, fully standardized hydraulic traits dataset and use it to assess regional variation in drought sensitivity and hydraulic trait ability to predict species distributions and long-term forest biomass accumulation. Parameters Κ50 and HSM50 vary markedly across the Amazon and are related to average long-term rainfall characteristics. Both Κ50 and HSM50 influence the biogeographical distribution of Amazon tree species. However, HSM50 was the only significant predictor of observed decadal-scale changes in forest biomass. Old-growth forests with wide HSM50 are gaining more biomass than are low HSM50 forests. We propose that this may be associated with a growthâmortality trade-off whereby trees in forests consisting of fast-growing species take greater hydraulic risks and face greater mortality risk. Moreover, in regions of more pronounced climatic change, we find evidence that forests are losing biomass, suggesting that species in these regions may be operating beyond their hydraulic limits. Continued climate change is likely to further reduce HSM50 in the Amazon6,7, with strong implications for the Amazon carbon sink
The effects of male age on sperm analysis by motile sperm organelle morphology examination (MSOME)
<p>Abstract</p> <p>Background</p> <p>This study aimed to investigate the influence of age on sperm quality, as analysed by motile sperm organelle morphology examination (MSOME).</p> <p>Methods</p> <p>Semen samples were collected from 975 men undergoing evaluation or treatment for infertility. Sperm cells were evaluated at 8400Ă magnification using an inverted microscope equipped with Nomarski (differential interference contrast) optics. Two forms of spermatozoa were considered: normal spermatozoa and spermatozoa with large nuclear vacuoles (LNV, defined as vacuoles occupying > 50% of the sperm nuclear area). At least 200 spermatozoa per sample were evaluated, and the percentages of normal and LNV spermatozoa were determined. The subjects were divided into three groups according to age: Group I, less than or equal to 35 years; Group II, 36-40 years; and Group III, greater than or equal to 41 years.</p> <p>Results</p> <p>There was no difference in the percentages of normal sperm between the two younger (I and II) groups (<it>P ></it>0.05). The percentage of normal sperm in the older group (III) was significantly lower than that in the younger (I and II) groups (<it>P </it>< 0.05). There was no difference in the percentage of LNV spermatozoa between the younger (I and II) groups (<it>P ></it>0.05). The percentage of LNV spermatozoa was significantly higher in the older group (III) than in the younger (I and II) groups (<it>P </it>< 0.05). Regression analysis demonstrated a significant decrease in the incidence of normal sperm with increasing age (<it>P </it>< 0.05; r = -0.10). However, there was a significant positive correlation between the percentage of spermatozoa with LNV and male age (<it>P </it>< 0.05, r = 0.10).</p> <p>Conclusion</p> <p>The results demonstrated a consistent decline in semen quality, as reflected by morphological evaluation by MSOME, with increased age. Considering the relationship between nuclear vacuoles and DNA damage, these age-related changes predict that increased paternal age should be associated with unsuccessful or abnormal pregnancy as a consequence of fertilisation with damaged spermatozoa. Given that sperm nuclear vacuoles can be evaluated more precisely at high magnification, these results support the routine use of MSOME for ICSI as a criterion for semen analysis.</p
Efficacy of the motile sperm organelle morphology examination (MSOME) in predicting pregnancy after intrauterine insemination
Background: Although the motile sperm organelle morphology examination (MSOME) was developed merely as a selection criterion, its application as a method for classifying sperm morphology may represent an improvement in the evaluation of semen quality. The aim of this study was to determine the prognostic value of normal sperm morphology using MSOME with regard to clinical pregnancy (CP) after intrauterine insemination (IUI).Methods: A total of 156 IUI cycles that were performed in 111 couples were prospectively analysed. Each subject received 75 IU of recombinant FSH every second day from the third day of the cycle. Beginning on the 10th day of the cycle, follicular development was monitored by vaginal ultrasound. When one or two follicles measuring at least 17 mm were observed, recombinant hCG was administered, and IUI was performed 12-14 h and 36-40 h after hCG treatment. Prior to the IUI procedure, sperm samples were analysed by MSOME at 8400x magnification using an inverted microscope that was equipped with DIC/Nomarski differential interference contrast optics. A minimum of 200 motile spermatozoa per semen sample were evaluated, and the percentage of normal spermatozoa in each sample was determined.Results: Pregnancy occurred in 34 IUI cycles (CP rate per cycle: 21.8%, per patient: 30.6%). Based on the MSOME criteria, a significantly higher percentage of normal spermatozoa was found in the group of men in which the IUI cycles resulted in pregnancy (2.6+/-3.1%) compared to the group that did not achieve pregnancy (1.2+/-1.7%; P = 0.019). Logistic regression showed that the percentage of normal cells in the MSOME was a determining factor for the likelihood of clinical pregnancy (OR: 1.28; 95% CI: 1.08 to 1.51; P = 0.003). The ROC curve revealed an area under the curve of 0.63 and an optimum cut-off point of 2% of normal sperm morphology. At this cut-off threshold, using the percentage of normal sperm morphology by MSOME to predict pregnancy was 50% sensitive with a 40% positive predictive value and 79% specificity with an 85% negative predictive value. The efficacy of using the percentage of normal sperm morphology by MSOME in predicting pregnancy was 65%.Conclusions: The present findings support the use of high-magnification microscopy both for selecting spermatozoa and as a routine method for analysing semen before performing IUI
Ărboles del Santuario HistĂłrico de Machu Picchu: Monitoreo de diversidad y carbono a largo plazo
Understanding how the richness, diversity, and carbon monitoring vary and are distributed through altitudinal gradients in Andean montane forests is essential to understand how these forests are adapting to global warming effects. Botanical explorations and general collections were carried out within the limits of the Historic Sanctuary of Machu Picchu in an altitude gradient of 1600 to 4200 m.a.s.l. Two permanent plots of 1.0 ha were established in the sectors of Intipunku (SHM â 01) at an altitude of 2,653 m.a.s.l and Kantupata (SHM-02) at an altitude of 3,200 m.a.s.l., with the standardized methodology of RAINFOR in 2013 and remedied in 2016. We updated the number of tree species for the Historic Sanctuary of Machu Picchu, 364 species are reported so far, this catalog includes all wild and cultivated species but also tree ferns and palm trees. In recent years, four new tree species have been described whose TYPE collections come from SHM forests: Ocotea alveatavan der Werff, Ocotea mollivillosavan der Werff (Lauraceae), Bunchosia cuscanaW.R. Anderson (Malpighiaceae), Ficus machupicchuensisC.C. Berg (Moraceae). In the two permanent plots, a total of 69 species were recorded in 1286 individuals. Individually in the SHM â 01 plot, 26 families, 36 genera and 45 species were recorded in 682 individuals; and in the SHM â 02 plot: 22 families, 28 genera and 31 species in 604 individuals. Stored aerial biomass was higher in the Intipunku sector (146 Mg ha-1) compared to Kantupata sector (101 Mg ha-1). Our research shows that the Andean forests of Machu Picchu provide important ecosystem services, and there is still much to do in terms of scientic research. The continued discovery of new tree species in the locality demonstrates the need for conservation to protect forests that support some of the highest levels of endemism in the world
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