scholarly journals New Records of Anopheles benarrochi B (Diptera: Culicidae) in Malaria Hotspots in the Amazon Regions of Ecuador and Peru

2021 ◽  
Author(s):  
Diego Morales Viteri ◽  
Manuela Herrera-Varela ◽  
Maribel Albuja ◽  
Cristina Quiroga ◽  
Gloria Diaz ◽  
...  
Keyword(s):  
Vector Control ◽  
Malaria Transmission ◽  
New Records ◽  
Final Analysis ◽  
Human Landing Catch ◽  
Light Traps ◽  
Control Units ◽  
Pcr Rflp ◽  
Human Landing ◽  
First Time

Abstract The increase in malaria transmission in the Amazon region motivated vector control units of the Ministry of Health of Ecuador and Peru to investigate Anopheles (Diptera: Culicidae) species present in transmission hotspots. Mosquitoes were collected using prokopack aspirators and CDC light traps (Ecuador) and human landing catch in Peru. In Ecuador, 84 Anopheles were captured from Pastaza, Morona Santiago, and Orellana provinces and identified morphologically [An. (An.) apicimacula Dyar and Knab, An. (Nys.) near benarrochi, An. (Nys.) near oswaldoi, An. (Nys.) near strodei, An. (An.) nimbus (Theobald, 1902), and An. (Nyssorhynchus) sp.]. In Peru, 1,150 Anopheles were collected in Andoas District. A subsample of 166 specimens was stored under silica and identified as An. near oswaldoi, An. darlingi, and An. (An.) mattogrossensis Lutz and Neiva. COI barcode region sequences were obtained for 137 adults (107 from Peru, 30 from Ecuador) identified by ITS2 PCR-RFLP as An. benarrochi Gabaldon, Cova Garcia, and Lopez and retained in the final analysis. Haplotypes from the present study plus An. benarrochi B GenBank sequences grouped separately from Brazilian An. benarrochi GenBank sequences by 44 mutation steps, indicating that the present study specimens were An. benarrochi B. Our findings confirm the presence of An. benarrochi B in Ecuador and reported here for the first time from the Amazonian provinces of Orellana and Morona Santiago. Furthermore, we confirm that the species collected in Andoas District in the Datem del Maranon Province, Peru, is An. benarrochi B, and we observed that it is highly anthropophilic. Overall, the known distribution of An. benarrochi B has been extended and includes southern Colombia, much of Peru and eastern Ecuador.

scholarly journals The Abundance and Biting Patterns of Culex quinquefasciatus Say (Culicidae) in the Coastal Region of Nigeria

ISRN Zoology ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Emmanuel C. Uttah ◽  
Gloria N. Wokem ◽  
Christiana Okonofua
Keyword(s):  
Culex Quinquefasciatus ◽  
Rainy Season ◽  
Coastal Region ◽  
Dry Season ◽  
Human Landing Catch ◽  
Light Traps ◽  
Transmission Potential ◽  
Human Landing ◽  
The Mean

This study was aimed at determining the abundance and biting patterns of Culex quinquefasciatus in the coastal region of Nigeria. Collections were done by human landing catch and by CDC miniature light traps from September 2005 to August 2006. A total of 3798 C. quinquefasciatus females were collected. The highest number of females was caught in the month of August and it represented nearly a quarter (24.0%) of the total females collected. In all, 38.8% of females dissected were parous. The abundance of C. quinquefasciatus followed the pattern of rainfall with the population starting to expand at the onset of the rains. The highest increase was found after the temperature had peaked. The mean of biting was 3.2 times more in the rainy season than in the dry season, whereas the transmission potential was higher in the dry season. C. quinquefasciatus is presently regarded as a biting nuisance having no significant epidemiological importance yet. Efforts at its control should be intensified before it is too late.

scholarly journals Does Cattle Milieu Provide a Potential Point to Target Wild ExophilicAnopheles arabiensis(Diptera: Culicidae) with Entomopathogenic Fungus? A Bioinsecticide Zooprophylaxis Strategy for Vector Control

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Issa N. Lyimo ◽  
Kija R. Ng'habi ◽  
Monica W. Mpingwa ◽  
Ally A. Daraja ◽  
Dickson D. Mwasheshe ◽  
...  
Keyword(s):  
Vector Control ◽  
Malaria Transmission ◽  
Entomopathogenic Fungus ◽  
Anopheles Arabiensis ◽  
Control Strategies ◽  
Field Conditions ◽  
Small Scale ◽  
Kilombero Valley ◽  
Scale Field ◽  
First Time

Background.Anopheles arabiensisis increasingly dominating malaria transmission in Africa. The exophagy in mosquitoes threatens the effectiveness of indoor vector control strategies. This study aimed to evaluate the effectiveness of fungus againstAn. arabiensiswhen applied on cattle and their environments.Methods. Experiments were conducted under semi-field and small-scale field conditions within Kilombero valley. The semi-field reared females of 5–7 days oldAn. arabiensiswere exposed to fungus-treated and untreated calf. Further, wildAn. arabiensiswere exposed to fungus-treated calves, mud-huts, and their controls. Mosquitoes were recaptured the next morning and proportion fed, infected, and survived were evaluated. Experiments were replicated three times using different individuals of calves.Results. A high proportion ofAn. arabiensiswas fed on calves (>0.90) and become infected (0.94) while resting on fungus-treated mud walls than on other surfaces. However, fungus treatments reduced fecundity and survival of mosquitoes.Conclusion. This study demonstrates for the first time the potential of cattle and their milieu for controllingAn. arabiensis. Most ofAn. arabiensiswere fed and infected while resting on fungus-treated mud walls than on other surfaces. Fungus treatments reduced fecundity and survival of mosquitoes. These results suggest deployment of bioinsecticide zooprophylaxis against exophilicAn. arabiensis.

scholarly journals Indoor and outdoor malaria transmission in two ecological settings in rural Mali: implications for vector control

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Moussa Keïta ◽  
Sidy Doumbia ◽  
Ibrahim Sissoko ◽  
Mahamoudou Touré ◽  
Sory Ibrahim Diawara ◽  
...  
Keyword(s):  
Vector Control ◽  
Malaria Transmission ◽  
Control Strategies ◽  
Indoor Residual Spraying ◽  
Credible Interval ◽  
Human Landing Catch ◽  
Malaria Vector Control ◽  
Anopheles Coluzzii ◽  
Sporozoite Rate ◽  
Indoor And Outdoor

Abstract Background Implementation and upscale of effective malaria vector control strategies necessitates understanding the multi-factorial aspects of transmission patterns. The primary aims of this study are to determine the vector composition, biting rates, trophic preference, and the overall importance of distinguishing outdoor versus indoor malaria transmission through a study at two communities in rural Mali. Methods Mosquito collection was carried out between July 2012 and June 2016 at two rural Mali communities (Dangassa and Koïla Bamanan) using pyrethrum spray-catch and human landing catch approaches at both indoor and outdoor locations. Species of Anopheles gambiae complex were identified by polymerase chain reaction (PCR). Enzyme-Linked -Immuno-Sorbent Assay (ELISA) were used to determine the origin of mosquito blood meals and presence of Plasmodium falciparum sporozoite infections. Results A total of 11,237 An. gambiae sensu lato (s.l.) were collected during the study period (5239 and 5998 from the Dangassa and Koïla Bamanan sites, respectively). Of the 679 identified by PCR in Dangassa, Anopheles coluzzii was the predominant species with 91.4% of the catch followed by An. gambiae (8.0%) and Anopheles arabiensis (0.6%). At the same time in Koïla Bamanan, of the 623 An. gambiae s.l., An. coluzzii accounted for 99% of the catch, An. arabiensis 0.8% and An. gambiae 0.2%. Human Blood Index (HBI) measures were significantly higher in Dangassa (79.4%; 95% Bayesian credible interval (BCI) [77.4, 81.4]) than in Koïla Bamanan (15.9%; 95% BCI [14.7, 17.1]). The human biting rates were higher during the second half of the night at both sites. In Dangassa, the sporozoite rate was comparable between outdoor and indoor mosquito collections. For outdoor collections, the sporozoite positive rate was 3.6% (95% BCI [2.1–4.3]) and indoor collections were 3.1% (95% BCI [2.4–5.0]). In Koïla Bamanan, the sporozoite rate was higher indoors at 4.3% (95% BCI [2.7–6.3]) compared with outdoors at 2.4% (95% BCI [1.1–4.2]). In Dangassa, corrected entomological inoculation rates (cEIRs) using HBI were 13.74 [95% BCI 9.21–19.14] infective bites/person/month (ib/p/m) at indoor, and 18.66 [95% BCI 12.55–25.81] ib/p/m at outdoor. For Koïla Bamanan, cEIRs were 1.57 [95% BCI 2.34–2.72] ib/p/m and 0.94 [95% BCI 0.43–1.64] ib/p/m for indoor and outdoor, respectively. EIRs were significantly higher at the Dangassa site than the Koïla Bamanan site. Conclusion The findings in this work may indicate the occurrence of active, outdoor residual malaria transmission is comparable to indoor transmission in some geographic settings. The high outdoor transmission patterns observed here highlight the need for additional strategies to combat outdoor malaria transmission to complement traditional indoor preventive approaches such as long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) which typically focus on resting mosquitoes.

scholarly journals Malaria in migrant agricultural workers in western Ethiopia: entomological assessment of malaria transmission risk

2021 ◽  
Author(s):  
Sisay Dugassa Lemma ◽  
Mathew Murphy ◽  
Sheleme Chibsa ◽  
Yehualashet Tadesse ◽  
Gedeon Yohannes ◽  
...  
Keyword(s):  
Vector Control ◽  
Malaria Transmission ◽  
Anopheles Arabiensis ◽  
Agricultural Development ◽  
Transmission Risk ◽  
Malaria Vectors ◽  
Residential Housing ◽  
Host Seeking ◽  
Human Landing ◽  
Western Ethiopia

Abstract Background Ethiopia has made great strides in malaria control over the last two decades. However, this progress has not been uniform and one concern has been reported high rates of malaria transmission in large agricultural development areas in western Ethiopia. Improved vector control is one way this transmission might be addressed, but little is known about malaria vectors in this part of the country. Methods To better understand the vector species involved in malaria transmission and their behaviour, human landing collections were conducted in Dangur woreda, Benishangul-Gumuz, between July and December 2017. This period encompasses the months with the highest rain and the peak mosquito population. Mosquitoes were identified to species and tested for the presence of Plasmodium sporozoites. Results The predominant species of the Anopheles collected was Anopheles arabiensis (1,733; i.e. 61.3% of the entire Anopheles), which was also the only species identified with sporozoites (Plasmodium falciparum and Plasmodium vivax). Anopheles arabiensis was collected as early in the evening as 18:00h-19:00h, and host-seeking continued until 5:00h-6:00h. Nearly equal numbers were collected indoors and outdoors. The calculated entomological inoculation rate for An. arabiensis for the study period was 1.41 infectious bites per month. More An. arabiensis were collected inside and outside worker’s shelters than in fields where workers were working at night. Conclusions Anopheles arabiensis is likely to be the primary vector of malaria in the agricultural development areas studied. High rates of human biting took place inside and outdoor near workers’ residential housing. Improved and targeted vector control in this area might considerably reduce malaria transmission.

scholarly journals Culicoides (Diptera: Ceratopogonidae) from Ceará State, northeastern Brazil: Diversity, new records and bionomic approaches.

2019 ◽  
Vol 11 (2) ◽  
pp. 137-144
Author(s):  
Maria Luiza Felippe-Bauer ◽  
Gilmara Pereira Gonzaga ◽  
Robson Cavalcante ◽  
Ricristhi Gomes ◽  
Rafaella Silva
Keyword(s):  
New Species ◽  
New Records ◽  
Abundant Species ◽  
Northeastern Brazil ◽  
Epidemiological Surveillance ◽  
Culicoides Species ◽  
Light Traps ◽  
Vector Species ◽  
Veterinary Importance ◽  
First Time

Introduction: little is known about the biodiversity of the genus Culicoides and the possible presence of vector species in Ceará State, Brazil. Objective: to improve the knowledge about the biodiversity and possible vectors presence in northeastern Brazil. Methods: with CDC light traps we surveyed Culicoides species in 18 municipalities from six mesoregions of Ceará State. Results: we collected 1 453 specimens (12 species). Culicoides guyanensis was the most abundant species, with 75,84% of the collected specimens. Culicoides venezuelensis is well distributed and is found in five Mesoregions. We recorded five species for the first time from Ceará State and seven from the surveyed municipalities; the presence of species with sanitary importance is discussed. Conclusion: with the addition of new species records, there are now 12 species known from Ceará State. The presence of species with medical and/or veterinary importance in the studied Mesoregions is indicative of the need of epidemiological surveillance in this state.

scholarly journals Malaria in Migrant Agricultural Workers in Dangur District, Benishangul-gumuz, Ethiopia. Entomological Assessment of Malaria Transmission Risk

2020 ◽  
Author(s):  
Sisay Dugassa Lemma ◽  
Mathew Murphy ◽  
Sheleme Chibsa ◽  
Yehualashet Tadesse ◽  
Gedeon Yohannes ◽  
...  
Keyword(s):  
Vector Control ◽  
Malaria Transmission ◽  
Anopheles Arabiensis ◽  
Agricultural Development ◽  
Transmission Risk ◽  
Malaria Vectors ◽  
Residential Housing ◽  
Host Seeking ◽  
Human Landing ◽  
Primary Vector

Abstract Background: Ethiopia has made great strides in malaria control. However, this progress has not been uniform and one concern has been reported high rates of malaria transmission in large agricultural development areas in western Ethiopia. Improved vector control is one way this transmission might be addressed, but little is known about malaria vectors in this part of the country. Methods: To better understand the vector species involved in malaria transmission and their behavior, human landing collections were conducted in Dangur woreda, Benishangul-Gumuz, between July and December 2017. Mosquitoes were identified to species and tested for presence of Plasmodium sporozoites. Results: The predominant species collected was Anopheles arabiensis (61.3% of all Anopheles), which was also the only species identified with sporozoites (P. falciparum and P. vivax). Anopheles arabiensis was collected as early in the evening as 18:00h-19:00h, and host-seeking continued until 5:00h-6:00h. Nearly equal numbers were collected indoors and outdoors. The calculated entomological inoculation rate for An. arabiensis for the study period was 1.41 infectious bites per month. More An. arabiensis were collected inside and outside worker’s shelters than in fields where workers were working at night. Conclusions: An. arabiensis is likely to be the primary vector of malaria in the agricultural development areas studied. High rates of human biting took place inside and outdoor near workers’ residential housing. Improved and targeted vector control in this area might considerably reduce malaria transmission.

scholarly journals Indoor and outdoor malaria transmission in two ecological settings in rural Mali: Implications for vector control

2021 ◽  
Author(s):  
Moussa KEITA ◽  
Sidy Doumbia ◽  
Ibrahim Sissoko ◽  
Mahamoudou Touré ◽  
Sory Ibrahim Diawara ◽  
...  
Keyword(s):  
Vector Control ◽  
Malaria Transmission ◽  
Control Strategies ◽  
Indoor Residual Spraying ◽  
Credible Interval ◽  
Human Landing Catch ◽  
Malaria Vector Control ◽  
Sporozoite Rate ◽  
Mosquito Collection ◽  
Indoor And Outdoor

Abstract Background: Implementation and upscale of effective malaria vector control strategies necessitates understanding the multi-factorial aspects of transmission patterns. The primary aims of this study are to determine the vector composition, biting rates, trophic preference, and the overall importance of distinguishing outdoor versus indoor malaria transmission through a study at two communities in rural Mali. Methods: Mosquito collection was carried out between July 2012 and June 2016 at two rural Mali communities (Dangassa and Koïla Bamanan) using pyrethrum spray-catch and human landing catch approaches at both indoor and outdoor locations. Species of Anopheles (An.) gambiae complex were identified by polymerase chain reaction (PCR). Enzyme-Linked -Immuno-Sorbent Assay (ELISA) were used to determine the origin of mosquito blood meals and presence of Plasmodium (P.) falciparum sporozoite infections.Results: A total of 11,237 An. gambiae (s.l.) were collected during the study period (5,239 and 5,998 from the Dangassa and Koïla Bamanan sites, respectively). Of the 679 identified by PCR in Dangassa, An. coluzzii was the predominant species with 91.4% of the catch followed by An. gambiae (8.0%) and An. arabiensis (0.6%). At the same time in Koïla Bamanan, of 623 An. gambiae s.l., An. coluzzii accounted for 99% of the catch, An. arabiensis 0.8% and An. gambiae 0.2%. Human Blood Index (HBI) measures were significantly higher in Dangassa (79.4%; 95% Bayesian credible interval (BCI) [77.4, 81.4]) than in Koïla Bamanan (15.9%; 95% BCI [14.7, 17.1]). The human biting rates were higher during the second half of the night at both sites. In Dangassa, the sporozoite rate was comparable between outdoor and indoor mosquito collections. For outdoor collections, the sporozoite positive rate was 3.6% (95% BCI [2.1-4.3]) and indoor collections were 3.1% (95% BCI [2.4-5.0]). In Koïla Bamanan, the sporozoite rate was higher indoors at 4.3% (95% BCI [2.7-6.3]) compared with outdoors at 2.4% (95% BCI [1.1- 4.2]). In Dangassa, corrected entomological inoculation rates (cEIRs) using HBI were 13.74 [95% BCI: 9.21—19.14] infective bites/person/month (ib/p/m) at indoor, and 18.66 [95% BCI 12.55—25.81] ib/p/m at outdoor. For Koïla Bamanan, cEIRs were 1.57 [95% BCI 2.34 —2.72] ib/p/m and 0.94 [95% BCI 0.43—1.64] ib/p/m for indoor and outdoor, respectively. EIRs were significantly higher at the Dangassa site than the Koïla Bamanan site.Conclusion: The findings in this work may indicate the occurrence of active, outdoor residual malaria transmission is comparable to indoor transmission in some geographic settings. The high outdoor transmission patterns observed here highlight the need for additional strategies to combat outdoor malaria transmission to complement traditional indoor preventive approaches such as long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) which typically focus on resting mosquitoes.

scholarly journals Extensive new Anopheles cryptic species involved in human malaria transmission in western Kenya

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Daibin Zhong ◽  
Elizabeth Hemming-Schroeder ◽  
Xiaoming Wang ◽  
Solomon Kibret ◽  
Guofa Zhou ◽  
...  
Keyword(s):  
Species Composition ◽  
Vector Control ◽  
Malaria Transmission ◽  
Cryptic Species ◽  
Mosquito Species ◽  
Western Kenya ◽  
Transmission Potential ◽  
Efficient Vector ◽  
Species Composition And Distribution ◽  
First Time

Abstract A thorough understanding of malaria vector species composition and their bionomic characteristics is crucial to devise effective and efficient vector control interventions to reduce malaria transmission. It has been well documented in Africa that malaria interventions in the past decade have resulted in major changes in species composition from endophilic Anopheles gambiae to exophilic An. arabiensis. However, the role of cryptic rare mosquito species in malaria transmission is not well known. This study examined the species composition and distribution, with a particular focus on malaria transmission potential of novel, uncharacterized Anopheles cryptic species in western Kenya. Phylogenetic analysis based on ITS2 and COX1 genes revealed 21 Anopheles mosquito species, including two previously unreported novel species. Unusually high rates of Plasmodium sporozoite infections were detected in An. funestus, An. gambiae and eight cryptic rare species. Plasmodium falciparum, P. malariae and P. ovale sporozoite infections were identified with large proportion of mixed species infections in these vectors. This study, for the first time, reports extensive new Anopheles cryptic species involved in the malaria transmission in western Kenya. These findings underscore the importance of non-common Anopheles species in malaria transmission and the need to target them in routine vector control and surveillance efforts.

scholarly journals Malaria in migrant agricultural workers in western Ethiopia: entomological assessment of malaria transmission risk

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Sisay Dugassa ◽  
Mathew Murphy ◽  
Sheleme Chibsa ◽  
Yehualashet Tadesse ◽  
Gedeon Yohannes ◽  
...  
Keyword(s):  
Vector Control ◽  
Malaria Transmission ◽  
Anopheles Arabiensis ◽  
Agricultural Development ◽  
Transmission Risk ◽  
Malaria Vectors ◽  
Residential Housing ◽  
Host Seeking ◽  
Human Landing ◽  
Western Ethiopia

Abstract Background Ethiopia has made great strides in malaria control over the last two decades. However, this progress has not been uniform and one concern has been reported high rates of malaria transmission in large agricultural development areas in western Ethiopia. Improved vector control is one way this transmission might be addressed, but little is known about malaria vectors in this part of the country. Methods To better understand the vector species involved in malaria transmission and their behaviour, human landing collections were conducted in Dangur woreda, Benishangul-Gumuz, between July and December 2017. This period encompasses the months with the highest rain and the peak mosquito population. Mosquitoes were identified to species and tested for the presence of Plasmodium sporozoites. Results The predominant species of the Anopheles collected was Anopheles arabiensis (1,733; i.e. 61.3 % of the entire Anopheles), which was also the only species identified with sporozoites (Plasmodium falciparum and Plasmodium vivax). Anopheles arabiensis was collected as early in the evening as 18:00 h-19:00 h, and host-seeking continued until 5:00 h-6:00 h. Nearly equal numbers were collected indoors and outdoors. The calculated entomological inoculation rate for An. arabiensis for the study period was 1.41 infectious bites per month. More An. arabiensis were collected inside and outside worker’s shelters than in fields where workers were working at night. Conclusions Anopheles arabiensis is likely to be the primary vector of malaria in the agricultural development areas studied. High rates of human biting took place inside and outdoor near workers’ residential housing. Improved and targeted vector control in this area might considerably reduce malaria transmission.

scholarly journals Impact of vector control interventions on malaria transmission intensity, outdoor vector biting rates and Anopheles mosquito species composition in Tororo, Uganda

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Alex K. Musiime ◽  
David L. Smith ◽  
Maxwell Kilama ◽  
John Rek ◽  
Emmanuel Arinaitwe ◽  
...  
Keyword(s):  
Vector Control ◽  
Malaria Transmission ◽  
Indoor Residual Spraying ◽  
Transmission Intensity ◽  
Intervention Period ◽  
Malaria Transmission Intensity ◽  
Predominant Species ◽  
High Transmission ◽  
Human Landing ◽  
The Impact

Abstract Background Long-lasting insecticidal nets (LLINs) and indoor residual spraying of insecticide (IRS) are widely recommended for the prevention of malaria in endemic regions. Data from human landing catches provide information on the impact of vector control on vector populations. Here, malaria transmission indoors and outdoors, before and after mass deployment of LLINs and IRS in Uganda was compared. Methods The study took place in Tororo district, a historically high transmission area where universal LLIN distribution was conducted in November 2013 and May 2017 and 6 rounds of IRS implemented from December 2014 to July 2018. Human landing catches were performed in 8 houses monthly from October 2011 to September 2012 (pre-intervention period) and every 4 weeks from November 2017 to October 2018 (post-intervention period). Mosquitoes were collected outdoors from 18:00 to 22:00 h and indoors from 18:00 to 06:00 h. Female Anopheles were tested for the presence of Plasmodium falciparum sporozoites and species identification performed using gross dissection and polymerase chain reaction (PCR). Results The interventions were associated with a decline in human biting rate from 19.6 to 2.3 female Anopheles mosquitoes per house per night (p < 0.001) and annual entomological inoculation rate from 129 to 0 infective bites per person per year (p < 0.001). The proportion of mosquitoes collected outdoors increased from 11.6 to 49.4% (p < 0.001). Prior to the interventions the predominant species was Anopheles gambiae sensu stricto (s.s.), which comprised an estimated 76.7% of mosquitoes. Following the interventions, the predominant species was Anopheles arabiensis, which comprised 99.5% of mosquitoes, with almost complete elimination of An. gambiae s.s. (0.5%). Conclusions Mass distribution of LLINs and 6 rounds of IRS dramatically decreased vector density and sporozoite rate resulting in a marked reduction in malaria transmission intensity in a historically high transmission site in Uganda. These changes were accompanied by a shift in vector species from An. gambiae s.s. to An. arabiensis and a relative increase in outdoor biting.

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