15 research outputs found
An Assessment of Perceived Crop Damage in a Tanzanian Village Impacted by Human-Elephant Conflict and an Investigation of Deterrent Properties of African Elephant (Loxodonta Africana) Exudates Using Bioassays
Human-elephant conflict (HEC) is on the rise in East Africa as habitat that was formerly occupied by elephants and other wildlife is being converted to farmland. African elephants (Loxodonta africana) will raid agricultural fields to feed on crops, and many agriculturalists attribute the majority of their crop damage to elephants. The first two objectives of this study were to evaluate the accuracy of this perception by comparing perceived crop damage by elephants and other factors to the actual, quantified crop damage, as well as to evaluate the effectiveness of deterrent methods against wildlife used by local farmers in a Tanzanian village. From May to November 2008, farmers from Miti Mirefu in northern Tanzania were interviewed about both their perception of crop damage and effectiveness of deterrents used. During the same period, the actual damage to their corn fields was measured and compared to the perceived damage. Participants perceived elephants to cause the most damage. Damage from elephants was infrequent, but when it occurred it was on a larger scale than damage attributed to other factors, suggesting that farmers assess damage based on the maximal damage by a single event. Damage from a lack of water was much more frequent and more severe on average than elephant damage. Traditional deterrent methods have not been effective and innovative techniques are difficult to institute on a wide scale. The final objective of this study was to assess compounds that might be used for crop protection. Elephants use chemical signals to communicate keep-away and attractant signals to conspecifics. Compounds within the exudates of African elephants can be identified and used as deterrents around crop fields or to attract elephants to a safe haven. From July to September 2008, at Ndarakwai Ranch in northern Tanzania, (E,E)-farnesol and 3-pentanone were bioassayed with wild African elephants. The compounds tested did not elicit bioactivity, but the importance of continued research on biologically meaningful signals is essential to effectively reducing HEC
Bridging the conservation and development trade‐off? A working landscape critique of a conservancy in the Maasai Mara
The recent call to halt biodiversity loss by protecting half the planet has been hotly contested because of the extent to which people might be excluded from these landscapes. It is clear that incorporating landscapes that implicitly work for indigenous people is vital to achieving any sustainable targets. We examine an attempt to balance the trade‐offs between conservation and development in Enonkishu Conservancy in the Maasai Mara, using a working landscape approach. Mobile livestock production strategies are theoretically consistent with wildlife‐based activities and can present a win‐win solution for both conservation and development. We explore the success and failings of Enonkishu's evolving attempts to achieve this: addressing the criticism of the conservation sector that it fails to learn from its mistakes. We found that Enonkishu has had considerable positive conservation outcomes, preventing the continued encroachment of farmland and maintaining and improving rangeland health relative to the surrounding area, while maintaining diverse and large populations of wildlife and livestock. The learning from certain ventures that failed, particularly on livestock, has created institutions and governance that, while still evolving, are more robust and relevant for conservancy members, by being fluid and inclusive. Practical implication: Diverse revenue streams (beyond tourism, including a residential estate, livestock venture and philanthropy) enabled Enonkishu to withstand the pressures of COVID‐19. Livestock is crucial for defining the vision of the conservancy, and the institutions and governance that underpin it
Post-intervention Status in Patients With Refractory Myasthenia Gravis Treated With Eculizumab During REGAIN and Its Open-Label Extension
OBJECTIVE: To evaluate whether eculizumab helps patients with anti-acetylcholine receptor-positive (AChR+) refractory generalized myasthenia gravis (gMG) achieve the Myasthenia Gravis Foundation of America (MGFA) post-intervention status of minimal manifestations (MM), we assessed patients' status throughout REGAIN (Safety and Efficacy of Eculizumab in AChR+ Refractory Generalized Myasthenia Gravis) and its open-label extension. METHODS: Patients who completed the REGAIN randomized controlled trial and continued into the open-label extension were included in this tertiary endpoint analysis. Patients were assessed for the MGFA post-intervention status of improved, unchanged, worse, MM, and pharmacologic remission at defined time points during REGAIN and through week 130 of the open-label study. RESULTS: A total of 117 patients completed REGAIN and continued into the open-label study (eculizumab/eculizumab: 56; placebo/eculizumab: 61). At week 26 of REGAIN, more eculizumab-treated patients than placebo-treated patients achieved a status of improved (60.7% vs 41.7%) or MM (25.0% vs 13.3%; common OR: 2.3; 95% CI: 1.1-4.5). After 130 weeks of eculizumab treatment, 88.0% of patients achieved improved status and 57.3% of patients achieved MM status. The safety profile of eculizumab was consistent with its known profile and no new safety signals were detected. CONCLUSION: Eculizumab led to rapid and sustained achievement of MM in patients with AChR+ refractory gMG. These findings support the use of eculizumab in this previously difficult-to-treat patient population. CLINICALTRIALSGOV IDENTIFIER: REGAIN, NCT01997229; REGAIN open-label extension, NCT02301624. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that, after 26 weeks of eculizumab treatment, 25.0% of adults with AChR+ refractory gMG achieved MM, compared with 13.3% who received placebo
Minimal Symptom Expression' in Patients With Acetylcholine Receptor Antibody-Positive Refractory Generalized Myasthenia Gravis Treated With Eculizumab
The efficacy and tolerability of eculizumab were assessed in REGAIN, a 26-week, phase 3, randomized, double-blind, placebo-controlled study in anti-acetylcholine receptor antibody-positive (AChR+) refractory generalized myasthenia gravis (gMG), and its open-label extension
Assessing Perceived And Documented Crop Damage In A Tanzanian Village Impacted By Human-Elephant Conflict (HEC)
In sub-Saharan Africa human-wildlife conflict (HWC) is a growing conservation issue and human-elephant conflict (HEC) is of special concern. Crop loss to wildlife comprises a main component of HWC. Deterrent methods for crop loss are numerous and such schemes could be more effective by an improved understanding of how farmers’ perceptions align with actual causes of crop loss. Our objective was to compare the perception by farmers of the causes and extent of crop damage to the measured crop damage in fields of maize (Zea mays) using different deterrent methods. We interviewed agriculturalists in the farming village of Miti Mirefu in northern Tanzania and documented the amount and causes of crop damage. Most participants were accurate in their perception of damage, but those who were not, tended to overestimate damage. Elephant damage was infrequent but severe and participants attributed crop damage to elephants more than any other cause. Agriculturalists must also realize the detrimental effects of regular, low-level impacts such as water-scarcity and small-scale crop raiders. Our methodological approach could be useful in other areas where elephants are one but not the sole contributing factor to crop loss. In such locales, aligning human perception and actual causation of crop loss could result in more efficient and effective crop protection programs
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Retrotransposons Are the Major Contributors to the Expansion of the Drosophila ananassae Muller F Element.
The discordance between genome size and the complexity of eukaryotes can partly be attributed to differences in repeat density. The Muller F element (∼5.2 Mb) is the smallest chromosome in Drosophila melanogaster, but it is substantially larger (>18.7 Mb) in D. ananassae To identify the major contributors to the expansion of the F element and to assess their impact, we improved the genome sequence and annotated the genes in a 1.4-Mb region of the D. ananassae F element, and a 1.7-Mb region from the D element for comparison. We find that transposons (particularly LTR and LINE retrotransposons) are major contributors to this expansion (78.6%), while Wolbachia sequences integrated into the D. ananassae genome are minor contributors (0.02%). Both D. melanogaster and D. ananassae F-element genes exhibit distinct characteristics compared to D-element genes (e.g., larger coding spans, larger introns, more coding exons, and lower codon bias), but these differences are exaggerated in D. ananassae Compared to D. melanogaster, the codon bias observed in D. ananassae F-element genes can primarily be attributed to mutational biases instead of selection. The 5' ends of F-element genes in both species are enriched in dimethylation of lysine 4 on histone 3 (H3K4me2), while the coding spans are enriched in H3K9me2. Despite differences in repeat density and gene characteristics, D. ananassae F-element genes show a similar range of expression levels compared to genes in euchromatic domains. This study improves our understanding of how transposons can affect genome size and how genes can function within highly repetitive domains
Retrotransposons Are the Major Contributors to the Expansion of the <i>Drosophila ananassae</i> Muller F Element.
The discordance between genome size and the complexity of eukaryotes can partly be attributed to differences in repeat density. The Muller F element (∼5.2 Mb) is the smallest chromosome in Drosophila melanogaster, but it is substantially larger (>18.7 Mb) in D. ananassae To identify the major contributors to the expansion of the F element and to assess their impact, we improved the genome sequence and annotated the genes in a 1.4-Mb region of the D. ananassae F element, and a 1.7-Mb region from the D element for comparison. We find that transposons (particularly LTR and LINE retrotransposons) are major contributors to this expansion (78.6%), while Wolbachia sequences integrated into the D. ananassae genome are minor contributors (0.02%). Both D. melanogaster and D. ananassae F-element genes exhibit distinct characteristics compared to D-element genes (e.g., larger coding spans, larger introns, more coding exons, and lower codon bias), but these differences are exaggerated in D. ananassae Compared to D. melanogaster, the codon bias observed in D. ananassae F-element genes can primarily be attributed to mutational biases instead of selection. The 5' ends of F-element genes in both species are enriched in dimethylation of lysine 4 on histone 3 (H3K4me2), while the coding spans are enriched in H3K9me2. Despite differences in repeat density and gene characteristics, D. ananassae F-element genes show a similar range of expression levels compared to genes in euchromatic domains. This study improves our understanding of how transposons can affect genome size and how genes can function within highly repetitive domains
Retrotransposons Are the Major Contributors to the Expansion of the Drosophila ananassae Muller F Element
The discordance between genome size and the complexity of eukaryotes can partly be attributed to differences in repeat density. The Muller F element (∼5.2 Mb) is the smallest chromosome in Drosophila melanogaster, but it is substantially larger (>18.7 Mb) in D. ananassae. To identify the major contributors to the expansion of the F element and to assess their impact, we improved the genome sequence and annotated the genes in a 1.4-Mb region of the D. ananassae F element, and a 1.7-Mb region from the D element for comparison. We find that transposons (particularly LTR and LINE retrotransposons) are major contributors to this expansion (78.6%), while Wolbachia sequences integrated into the D. ananassae genome are minor contributors (0.02%). Both D. melanogaster and D. ananassae F-element genes exhibit distinct characteristics compared to D-element genes (e.g., larger coding spans, larger introns, more coding exons, and lower codon bias), but these differences are exaggerated in D. ananassae. Compared to D. melanogaster, the codon bias observed in D. ananassae F-element genes can primarily be attributed to mutational biases instead of selection. The 5′ ends of F-element genes in both species are enriched in dimethylation of lysine 4 on histone 3 (H3K4me2), while the coding spans are enriched in H3K9me2. Despite differences in repeat density and gene characteristics, D. ananassae F-element genes show a similar range of expression levels compared to genes in euchromatic domains. This study improves our understanding of how transposons can affect genome size and how genes can function within highly repetitive domains
Long-term efficacy and safety of eculizumab in Japanese patients with generalized myasthenia gravis: A subgroup analysis of the REGAIN open-label extension study
The terminal complement inhibitor eculizumab was shown to improve myasthenia gravis-related symptoms in the 26-week, phase 3, randomized, double-blind, placebo-controlled REGAIN study (NCT01997229). In this 52-week sub-analysis of the open-label extension of REGAIN (NCT02301624), eculizumab's efficacy and safety were assessed in 11 Japanese and 88 Caucasian patients with anti-acetylcholine receptor antibody-positive refractory generalized myasthenia gravis. For patients who had received placebo during REGAIN, treatment with open-label eculizumab resulted in generally similar outcomes in the Japanese and Caucasian populations. Rapid improvements were maintained for 52 weeks, assessed by change in score from open-label extension baseline to week 52 (mean [standard error]) using the following scales (in Japanese and Caucasian patients, respectively): Myasthenia Gravis Activities of Daily Living (−2.4 [1.34] and − 3.3 [0.65]); Quantitative Myasthenia Gravis (−2.9 [1.98] and − 4.3 [0.79]); Myasthenia Gravis Composite (−4.5 [2.63] and − 4.9 [1.19]); and Myasthenia Gravis Quality of Life 15-item questionnaire (−8.6 [5.68] and − 6.5 [1.93]). Overall, the safety of eculizumab was consistent with its known safety profile. In this interim sub-analysis, the efficacy and safety of eculizumab in Japanese and Caucasian patients were generally similar, and consistent with the overall REGAIN population