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1.
Nature ; 572(7767): 56-61, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31316207

RESUMEN

The radiation-based sterile insect technique (SIT) has successfully suppressed field populations of several insect pest species, but its effect on mosquito vector control has been limited. The related incompatible insect technique (IIT)-which uses sterilization caused by the maternally inherited endosymbiotic bacteria Wolbachia-is a promising alternative, but can be undermined by accidental release of females infected with the same Wolbachia strain as the released males. Here we show that combining incompatible and sterile insect techniques (IIT-SIT) enables near elimination of field populations of the world's most invasive mosquito species, Aedes albopictus. Millions of factory-reared adult males with an artificial triple-Wolbachia infection were released, with prior pupal irradiation of the released mosquitoes to prevent unintentionally released triply infected females from successfully reproducing in the field. This successful field trial demonstrates the feasibility of area-wide application of combined IIT-SIT for mosquito vector control.


Asunto(s)
Aedes/microbiología , Aedes/fisiología , Control de Mosquitos/métodos , Mosquitos Vectores/microbiología , Mosquitos Vectores/fisiología , Wolbachia/patogenicidad , Aedes/crecimiento & desarrollo , Animales , China , Copulación , Estudios de Factibilidad , Femenino , Humanos , Mordeduras y Picaduras de Insectos/prevención & control , Larva/crecimiento & desarrollo , Larva/microbiología , Larva/fisiología , Masculino , Mosquitos Vectores/crecimiento & desarrollo , Control de Calidad , Reproducción
2.
PLoS Negl Trop Dis ; 18(9): e0012523, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39325838

RESUMEN

The spread and invasion of the urban malaria vector Anopheles stephensi has emerged as a significant threat to ongoing malaria control and elimination efforts, particularly in Africa. The successful use of the maternally inherited endosymbiotic bacterium Wolbachia for arbovirus control has inspired the exploration of similar strategies for managing malaria vectors, necessitating the establishment of a stable Wolbachia-Anopheles symbiosis. In this study, we successfully transferred Wolbachia wPip into An. stephensi, resulting in the establishment of a stable transinfected HP1 line with 100% maternal transmission efficiency. We demonstrate that wPip in the HP1 line induces nearly complete unidirectional cytoplasmic incompatibility (CI) and maintains high densities in both somatic and germline tissues. Despite a modest reduction in lifespan and female reproductive capacity, our results suggest the Wolbachia infection in the HP1 line has little impact on life history traits, body size, and male mating competitiveness, as well as the ability of its larvae to tolerate rearing temperatures up to 38°C, although wPip densities moderately decrease when larvae are exposed to a constant 33°C and diurnal cyclic temperatures of 27-36°C and 27-38°C. These findings highlight the potential of the HP1 line as a robust candidate for further development in malaria control.


Asunto(s)
Anopheles , Malaria , Mosquitos Vectores , Simbiosis , Wolbachia , Animales , Wolbachia/fisiología , Anopheles/microbiología , Anopheles/fisiología , Malaria/transmisión , Malaria/prevención & control , Femenino , Mosquitos Vectores/microbiología , Mosquitos Vectores/fisiología , Masculino , Control de Mosquitos/métodos , Larva/microbiología
3.
Sci Robot ; 9(92): eadj6261, 2024 07 31.
Artículo en Inglés | MEDLINE | ID: mdl-39083578

RESUMEN

Effective mosquito population suppression has been repeatedly demonstrated in field trials through the release of male mosquitoes to induce sterile mating with wild females using the incompatible insect technique (IIT), the sterile insect technique (SIT), or their combination. However, upscaling these techniques requires a highly efficient and scalable approach for the sex separation of mass-reared mosquitoes to minimize the unintentional release of females, which can lead to either population replacement or biting nuisance, a major bottleneck up to now. Here, we report the successful development of an automated mosquito pupa sex sorter that can effectively separate large numbers of males from females for population suppression of Aedes aegypti, A. albopictus, and Culex quinquefasciatus. The male production capacity of the automated sex sorter was increased by ~17-fold compared with manual sex separation with the Fay-Morlan sorter and enabled one person to separate 16 million males per week. With ~0.5% female contamination, the produced males exhibited high flight ability and mating performance. The field trial demonstrates that the quality of A. albopictus males produced using the automated sex sorter is suitable for inducing population suppression. These results indicate that the automated sex sorter offers the potential to upscale IIT and SIT against mosquito vectors for disease control.


Asunto(s)
Aedes , Control de Mosquitos , Conducta Sexual Animal , Animales , Masculino , Femenino , Aedes/fisiología , Control de Mosquitos/instrumentación , Control de Mosquitos/métodos , Conducta Sexual Animal/fisiología , Pupa/fisiología , Culex/fisiología , Automatización , Robótica/instrumentación , Control Biológico de Vectores/métodos , Diseño de Equipo
4.
Front Plant Sci ; 14: 1230149, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38269140

RESUMEN

Disturbance alters environmental conditions in forests. Plants growing in forests with different disturbance histories in diverse environments may adopt varying life history strategies, but few studies focus on this effect. This study comprehensively investigated plant biodiversity, biomass, and functional traits in subtropical forests with two different disturbance histories in east China to explore differences in life history strategies. Biodiversity was slightly higher in disturbed compared to conserved forests. Significantly higher biomass was measured in conserved relative to disturbed evergreen broadleaved forests (P < 0.05). In conserved forests, leaf tissue density (LTD) was significantly higher and leaf thickness (LT), leaf dry matter content (LDMC), twig tissue density (TTD), twig dry matter content (TDMC), bark tissue density (BTD) and dry matter content (BDMC), and stem tissue density (STD) and dry matter content (SDMC) were significantly lower than in disturbed forests (P < 0.05). In terms of associated plant biodiversity, biomass, and functional traits, conserved forests adopted a resource acquisition strategy, reducing biodiversity and developing multiple functional traits such as high leaf area and specific leaf area and low LT, LDMC, TTD, TDMC, BTD, BDMC, STD, and SDMC to support a high biomass accumulation rate. Disturbed forests adopted a resource conservation strategy, enhancing biodiversity and developing converse trait combinations to lower the rate of biomass accumulation. A comprehensive investigation of plant biodiversity, biomass, and functional traits and subsequent assessment of plant life history strategies in conserved and disturbed forests will aid investigations of regional biodiversity and carbon reserves, contribute data to the TRY and Chinese plant trait databases, and improve ecological management and restoration efforts in east China.

5.
J Chem Theory Comput ; 18(8): 4836-4845, 2022 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-35834742

RESUMEN

Accurate virtual high-throughput screening (VHTS) of transition metal complexes (TMCs) remains challenging due to the possibility of high multireference (MR) character that complicates property evaluation. We compute MR diagnostics for over 5,000 ligands present in previously synthesized octahedral mononuclear transition metal complexes in the Cambridge Structural Database (CSD). To accomplish this task, we introduce an iterative approach for consistent ligand charge assignment for ligands in the CSD. Across this set, we observe that the MR character correlates linearly with the inverse value of the averaged bond order over all bonds in the molecule. We then demonstrate that ligand additivity of the MR character holds in TMCs, which suggests that the TMC MR character can be inferred from the sum of the MR character of the ligands. Encouraged by this observation, we leverage ligand additivity and develop a ligand-derived machine learning representation to train neural networks to predict the MR character of TMCs from properties of the constituent ligands. This approach yields models with excellent performance and superior transferability to unseen ligand chemistry and compositions.


Asunto(s)
Complejos de Coordinación , Elementos de Transición , Complejos de Coordinación/química , Ligandos , Aprendizaje Automático , Elementos de Transición/química
6.
PhytoKeys ; 192: 29-36, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35437385

RESUMEN

Torreyadapanshanica X.F.Jin, Y.F.Lu & Zi L.Chen, a new species endemic to central Zhejiang, East China, is described and illustrated. This new species is most similar to T.jiulongshanensis (Z.Y.Li, Z.C.Tang & N.Kang) C.C.Pan, J.L.Liu & X.F.Jin, but differs in having leaves with an acuminate apex (vs. leaves with an acute apex), broadly ovoid-globose or globose seeds (vs. obovoid to narrowly obovoid seeds), slightly emarginate at the apex and obtuse-rounded at the base (vs. both acute at the apex and base), testa with irregular shallow grooves (vs. testa smooth or sometimes slightly concave). The diagnostic characters are critically compared and an IUCN assessment for the risk to the new species is estimated.

7.
Front Microbiol ; 11: 1638, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32765466

RESUMEN

Successful field trials have been reported as part of the effort to develop the maternally transmitted endosymbiontic bacteria Wolbachia as an intervention agent for controlling mosquito vectors and their transmitted diseases. In order to further improve this novel intervention, artificially transinfected mosquitoes must be optimized to display maximum pathogen blocking, the desired cytoplasmic incompatibility (CI) pattern, and the lowest possible fitness cost. Achieving such optimization, however, requires a better understanding of the interactions between the host and various Wolbabachia strains and their combinations. Here, we transferred the Wolbachia wMel strain by embryonic microinjection into Aedes albopictus, resulting in the successful establishment of a transinfected line, HM (wAlbAwAlbBwMel), with a triple-strain infection comprising wMel, wAlbA, and wAlbB. Surprisingly, no CI was induced when the triply infected males were crossed with the wild-type GUA females or with another triply infected HC females carrying wPip, wAlbA, and wAlbB, but specific removal of wAlbA from the HM (wAlbAwAlbBwMel) line resulted in the expression of CI after crosses with lines infected by either one, two, or three strains of Wolbachia. The transinfected line showed perfect maternal transmission of the triple infection, with fluctuating egg hatch rates that improved to normal levels after repeated outcrosses with GUA line. Strain-specific qPCR assays showed that wMel and wAlbB were present at the highest densities in the ovaries and midguts, respectively, of the HM (wAlbAwAlbBwMel) mosquitoes. These finding suggest that introducing a novel strain of Wolbachia into a Wolbachia-infected host may result in complicated interactions between Wolbachia and the host and between the various Wolbachia strains, with competition likely to occur between strains in the same supergroup.

8.
J Xray Sci Technol ; 17(4): 355-65, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19923691

RESUMEN

This study introduces a method to reduce the artefact caused by metal implant, and improve the image quality. The factors affecting the image quality of the existing methods are analysed from a different point of view. The observed projection is decomposed into several components including the correspondence of biological tissues, the correspondence of metal implant, noises, and inconsistencies caused by beam hardening. The correspondence of metal implant is identified by initial reconstruction and forward modelling, and the noises are detected and isolated from the projection in wavelet domain. The inconsistencies are approximated and compensated. A patient with medial epicondyle of right femur replaced using femoral component made by Biomet Inc was scanned using a GE Lightspeed 16 X-ray CT scanner and the observed projection is processed by this method. The output image shows that all of the streaking caused by metal implant is eliminated, and the darkness areas caused by beam hardening are retrieved. Comparing with the default output of the CT scanner, the image quality has been significantly improved.


Asunto(s)
Procesamiento de Imagen Asistido por Computador/métodos , Metales , Prótesis e Implantes , Tomografía Computarizada por Rayos X/métodos , Algoritmos , Artefactos , Fémur/diagnóstico por imagen , Fémur/cirugía , Humanos , Modelos Teóricos
9.
Int J Biochem Mol Biol ; 2(2): 183-189, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21968748

RESUMEN

Osteoclasts are large, multinucleated cells responsible for the resorption of mineralized bone matrix. These cells are critical players in the bone turnover involved in bone homeostasis. Osteoclast activity is connected to the establishment and expansion of skeletal metastases from a number of primary neoplasms. Thus, the formation and activation of osteoclasts is an area of research with many potential avenues for clinical translation. Past studies of osteoclast biology have utilized primary murine cells cultured in vitro. Recently, techniques have been described that involve the generation of osteoclasts from human precursor cells. However, these protocols are often time-consuming and insufficient for generating large numbers of osteoclasts. We therefore developed a simplified protocol by which human osteoclasts may be easily and reliably generated in large numbers in vitro. In this study, osteoclasts were differentiated from bone marrow cells that had been aliquotted and frozen. Cells were generated by culture with recombinant macrophage colony-stimulating factor (M-CSF) and receptor activator of NF-κB ligand (RANKL). Both human and murine RANKL were shown to efficiently generate osteoclasts, although higher concentrations of murine RANKL were required. Formation of osteoclasts was demonstrated qualitatively by tartrate-resistant acid phosphatase (TRAP) staining. These cells were fully functional, as confirmed by their ability to form resorption pits on cortical bone slices. Functional human osteoclasts can be difficult to generate in vitro by current protocols. We have demonstrated a simplified system for the generation of human osteoclasts in vitro that allows for large numbers of osteoclasts to be obtained from a single donor.

10.
Conf Proc IEEE Eng Med Biol Soc ; 2005: 3340-3, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-17282961

RESUMEN

Computed Tomograghy has played a key role in bone structure imaging for over two decades. However, when a metal implant present in the sample, the reconstructions are seriously distorted by artefacts, and no method has successfully met the clinical demands. This paper presents a new method for partial reconstruction in Computed Tomography. The metal implant is reconstructed separately and the correspondence is isolated from the projection. The boundary between the metal implants and other tissues are clearer. The method is demonstrated by experiments.

11.
Biochemistry ; 43(33): 10653-63, 2004 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-15311926

RESUMEN

The three-dimensional structure of bovine pancreatic (bp) DNase revealed that its N- and C-termini form an antiparallel beta-sheet structure. The involvement of this beta-sheet structure in the active protein folding of bpDNase was thus investigated via a series of deletion and substitution variants. Several substitution variants of N-terminal Leu1 and C-terminal Leu259, and one variant with only the last Thr260 deleted, remained fully active. However, the other deletion variants, in which 2-10 amino acid residues were removed from the C- or N-terminus, all lost the DNase activity. The results indicated that the backbone hydrogen bonding in the antiparallel beta-sheet, rather than the side-chain interactions, is crucial for the correct protein folding. When the deletion variants were complemented with synthetic peptides of the deleted N- or C-terminal sequences, the DNase activity was generated. The highest DNase activity was generated when the C-terminal 10-residue-deleted brDNase(Delta251-260) was admixed with the C-terminal 10-residue peptide (peptide C10) in a molar ratio of 1:400. The noncovalent binding between brDNase(Delta251-260) and peptide C10 exhibited a dissociation constant of 48 microM. Circular dichroism spectra showed that the deletion variants were partially folded with mainly helical structures and that admixture with corresponding peptides facilitated their folding into the nativelike beta-sheet-rich structure. Thermal denaturation profiles also revealed that the transition temperature for brDNase(Delta251-260) was increased from 55 to 63 degrees C after incubation with peptide C10. The folding activation process for the deletion variant occurred in two stages, and Ca(2+) was required.


Asunto(s)
Desoxirribonucleasa I/química , Fragmentos de Péptidos/farmacología , Pliegue de Proteína , Sustitución de Aminoácidos , Animales , Bovinos , Estabilidad de Enzimas/efectos de los fármacos , Enlace de Hidrógeno , Mutagénesis Sitio-Dirigida , Páncreas/enzimología , Fragmentos de Péptidos/química , Estructura Secundaria de Proteína , Eliminación de Secuencia , Temperatura
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