41,652 research outputs found
Preliminary studies developing methods for the control of Chrysomya putoria, the African latrine fly, in pit latrines in The Gambia.
No full textOBJECTIVE: To explore ways of controlling Chrysomya putoria, the African latrine fly, in pit latrines. As pit latrines are a major source of these flies, eliminating these important breeding sites is likely to reduce village fly populations, and may reduce the spread of diarrhoeal pathogens. METHODS: We treated 24 latrines in a Gambian village: six each with (i) pyriproxyfen, an insect juvenile hormone mimic formulated as Sumilarv(®) 0.5 G, a 0.5% pyriproxyfen granule, (ii) expanded polystyrene beads (EPB), (iii) local soap or (iv) no treatment as controls. Flies were collected using exit traps placed over the drop holes, weekly for five weeks. In a separate study, we tested whether latrines also function as efficient flytraps using the faecal odours as attractants. We constructed six pit latrines each with a built-in flytrap and tested their catching efficiency compared to six fish-baited box traps positioned 10 m from the latrine. Focus group discussions conducted afterwards assessed the acceptability of the flytrap latrines. RESULTS: Numbers of emerging C. putoria were reduced by 96.0% (95% CIs: 94.5-97.2%) 4-5 weeks after treatment with pyriproxyfen; by 64.2% (95% CIs: 51.8-73.5%) after treatment with local soap; by 41.3% (95% CIs = 24.0-54.7%) after treatment with EPB 3-5 weeks after treatment. Flytraps placed on latrines collected C. putoria and were deemed acceptable to local communities. CONCLUSIONS: Sumilarv 0.5 G shows promise as a chemical control agent, whilst odour-baited latrine traps may prove a useful method of non-chemical fly control. Both methods warrant further development to reduce fly production from pit latrines. A combination of interventions may prove effective for the control of latrine flies and the diseases they transmit
An alternative mechanism of clathrin-coated pit closure revealed by ion conductance microscopy
No full textCurrent knowledge of the structural changes taking place during clathrin-mediated endocytosis is largely based on electron microscopy images of fixed preparations and x-ray crystallography data of purified proteins. In this paper, we describe a study of clathrin-coated pit dynamics in living cells using ion conductance microscopy to directly image the changes in pit shape, combined with simultaneous confocal microscopy to follow molecule-specific fluorescence. We find that 70% of pits closed with the formation of a protrusion that grew on one side of the pit, covered the entire pit, and then disappeared together with pit-associated clathrin-enhanced green fluorescent protein (EGFP) and actin-binding protein-EGFP (Abp1-EGFP) fluorescence. This was in contrast to conventionally closing pits that closed and cleaved from flat membrane sheets and lacked accompanying Abp1-EGFP fluorescence. Scission of both types of pits was found to be dynamin-2 dependent. This technique now enables direct spatial and temporal correlation between functional molecule-specific fluorescence and structural information to follow key biological processes at cell surfaces
Specialized learning in antlions (Neuroptera: Myrmeleontidae), pit-digging predators, shortens vulnerable larval stage
No full textFormal Correction: This article has been formally corrected to address the following errors. Figures 2 and 3 were switched in production. The image listed as Figure 3 is actually Figure 2, and the image listed as Figure 2 is actually Figure 3. The legends are correct.Unique in the insect world for their extremely sedentary predatory behavior, pit-dwelling larval antlions dig pits, and then sit at the bottom and wait, sometimes for months, for prey to fall inside. This sedentary predation strategy, combined with their seemingly innate ability to detect approaching prey, make antlions unlikely candidates for learning. That is, although scientists have demonstrated that many species of insects possess the capacity to learn, each of these species, which together represent multiple families from every major insect order, utilizes this ability as a means of navigating the environment, using learned cues to guide an active search for food and hosts, or to avoid noxious events. Nonetheless, we demonstrate not only that sedentary antlions can learn, but also, more importantly, that learning provides an important fitness benefit, namely decreasing the time to pupate, a benefit not yet demonstrated in any other species. Compared to a control group in which an environmental cue was presented randomly vis-à-vis daily prey arrival, antlions given the opportunity to associate the cue with prey were able to make more efficient use of prey and pupate significantly sooner, thus shortening their long, highly vulnerable larval stage. Whereas ‘‘median survival time,’’ the point at which half of the animals in each group had pupated, was 46 days for antlions receiving the Learning treatment, that point never was reached in antlions receiving the Random treatment, even by the end of the experiment on Day 70. In addition, we demonstrate a novel manifestation of antlions’ learned response to cues predicting prey arrival, behavior that does not match the typical ‘‘learning curve’’ but which is well-adapted to their sedentary predation strategy. Finally, we suggest that what has long appeared to be instinctive predatory behavior is likely to be highly modified and shaped by learning.Peer reviewe
<i>In vivo</i> effect of NIR-PIT for MDAMB468 tumor (one shot NIR-PIT).
No full text<p>(A) NIR-PIT regimen. Fluorescence images were obtained at each time point as indicated. (B) In vivo fluorescence real-time imaging of tumor bearing mice in response to NIR-PIT. The tumor treated by NIR-PIT showed decreasing IR700 fluorescence after NIR-PIT. (C) Tumor growth was significantly inhibited in the NIR-PIT treatment groups with cet-IR700 (n = 10–11, **<i>p</i> < 0.01 vs control and light only group, Bonferroni’s test with ANOVA). (D) Significantly prolonged survival was observed in the APC i.v. only group and the NIR-PIT treatment group with cet-IR700 (n = 10–11, *<i>p</i> < 0.05 vs control, <sup>#</sup><i>p</i> < 0.05 vs i.v. group, **<i>p</i> < 0.001 vs control and light only group, by Log-rank test).</p
<i>In vivo</i> effect of NIR-PIT for MDAMB468 tumor (“three split” NIR-PIT).
No full text<p>(A) NIR-PIT regimen. (B) Tumor growth was significantly inhibited in the NIR-PIT treatment groups (n = 10–13, **<i>p</i> < 0.001 vs other groups, Bonferroni’s test with ANOVA). (C) Significantly prolonged survival was observed in the APC i.v. only group and NIR-PIT treatment group (n = 10–13, **<i>p</i> < 0.001 vs other groups, by Log-rank test).</p
<i>In vivo</i> effect of PIT for MDAMB468 tumor (“two split” NIR-PIT).
No full text<p>(A) NIR-PIT regimen. (B) Tumor growth was significantly inhibited in the NIR-PIT treatment groups (n = 10–13, **<i>p</i> < 0.01 vs other groups, Bonferroni’s test with ANOVA). (C) Significantly prolonged survival was observed in the APC i.v. only group and the NIR-PIT treatment group (n = 10–13, **<i>p</i> < 0.01 vs other groups, by Log-rank test).</p
<i>GmmOr6</i> and <i>GmmOr9</i> are transcribed in adjacent ORNs that encapsulate the sensory pit.
No full text(A-D) In situ hybridization to GmmOr6 (red) combined with anti-Elav immunostaining (green). (A) GmmOr6, (B) anti-Elav, and (C) merged image of the whole antenna. (D) Magnified merged image of the sensory pit without DIC. The circular structure in the center of the image that is uniformly green is autofluorescent cuticle of the pit. Likewise, the green fluorescence in the upper right corner is cuticular autofluorescence from the sacculus. (E-H) In situ hybridization to GmmOr9 (red) combined with anti-Elav immunostaining (green). (E) GmmOr9, (F) anti-Elav, and (G) merged image of the whole antenna. (H) Magnified merged image of the sensory pit without DIC. (I-L) Double in situ hybridization to GmmOr6 and GmmOr9 (both red) combined with anti-Elav immunostaining (green). (I) GmmOr6 and GmmOr9, (J) anti-Elav, and (K) merged image of the whole antenna. (L) Magnified merged image of the sensory pit without DIC.</p
<i>Ex vivo</i> GFP fluorescence imaging after repeated PIT in bilateral N87-GFP flank model.
No full text<p>(A) PIT regimen. Fluorescence images of <i>ex vivo</i> tumors were obtained at each time point as indicated. (B) <i>Ex vivo</i> fluorescence imaging of N87-GFP tumor in response to PIT. Fluorescence changes are seen with both GFP and IR700 fluorescence in response to PIT. (C) Fluorescence images were obtained at each time point as indicated. (D) <i>In vivo</i> fluorescence real-time imaging of bilateral flank tumor bearing mice in response to repeated PIT. GFP-fluorescence intensity of the tumor was almost eliminated after the second PIT.</p
<i>In vivo</i> effect of NIR-PIT for MDAMB231 tumor.
No full text<p>(A) NIR-PIT regimen. Fluorescence images were obtained at each time point as indicated. (B) In vivo fluorescence real-time imaging of tumor bearing mice in response to NIR-PIT. The tumor treated by NIR-PIT showed decreasing IR700 fluorescence after NIR-PIT. (C) Tumor growth was significantly inhibited in the PIT treatment groups with cet-IR700 (n = 10–13, *<i>p</i> < 0.05 vs i.v. group, **<i>p</i> < 0.01 vs control and light only group, Bonferroni’s test with ANOVA). (D) Significantly prolonged survival was observed in the NIR-PIT treatment group with cet-IR700 (n = 10–13, *<i>p</i> < 0.05 vs other groups, by Log-rank test).</p
GFP fluorescence imaging of PIT <i>in vivo</i> in bilateral N87-GFP flank model.
No full text<p>(A) PIT regimen. Fluorescence images were obtained at each time point as indicated. (B) <i>In vivo GFP</i> fluorescence real-time imaging of bilateral flank tumor bearing mice in response to PIT. The tumor treated by PIT showed decreasing GFP fluorescence after PIT. (C) Quantitative analysis of GFP fluorescence intensities (total intensity/tumor) in N87-GFP tumor bearing mice showed significantly decreased fluorescence between the control group and the PIT group (n = 5 mice in each group, (*p = 0.0118<0.05, vs. control) (*p = 0.0016<0.01, vs. NIR light) (*p = 0.0012<0.01, vs. APSC) (**p = 0.0010<0.01, vs. control) (**p = 0.0003<0.001, vs. NIR light) (**p = 0.0003<0.001, vs. APSC) (***p = 0.0049<0.01, vs. control) (***p = 0.0039<0.01, vs. NIR-light) (***p = 0.0012<0.01, vs. APSC), Tukey’s test with ANOVA).</p
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