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1.
J Insect Sci ; 24(2)2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38597910

RESUMEN

Larval habitats of blood-feeding stable flies, Stomoxys calcitrans (L.) (Diptera: Muscidae), overlap with foraging sites of black blow flies, Phormia regina (Meigen) (Diptera: Calliphoridae). We tested the hypothesis that bacteria in blow fly excreta inform oviposition decisions by female stable flies. In laboratory 2-choice bioassays, we offered gravid female stable flies fabric-covered agar plates as oviposition sites that were kept sterile or inoculated with either a blend of 7 bacterial strains isolated from blow fly excreta (7-isolate-blend) or individual bacterial isolates from that blend. The 7-isolate-blend deterred oviposition by female stable flies, as did either of 2 strains of Morganella morganii subsp. sibonii. Conversely, Exiguobacterium sp. and Serratia marcescens each prompted oviposition by flies. The flies' oviposition decisions appear to be guided by bacteria-derived semiochemicals as the bacteria could not be physically accessed. Oviposition deterrence caused by semiochemicals of the 7-isolate-blend may help stable flies avoid competition with blow flies. The semiochemicals of bioactive bacterial strains could be developed as trap lures to attract and capture flies and deter their oviposition in select larval habitats.


Asunto(s)
Morganella , Muscidae , Femenino , Animales , Calliphoridae , Oviposición , Larva , Bacterias , Feromonas
2.
Microorganisms ; 12(3)2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38543659

RESUMEN

Following blood meals or questing bouts, hard ticks (Ixodidae) must locate moist off-host microhabitats as refuge. Soil-dwelling fungi, including entomopathogenic Beauveria bassiana (Bb), thrive in moist microhabitats. Working with six species of ixodid ticks in olfactometer bioassays, we tested the hypothesis that ticks avoid Bb. Contrary to our prediction, nearly all ticks sought, rather than avoided, Bb-inoculated substrates. In further bioassays with female black-legged ticks, Ixodes scapularis, ticks oriented towards both harmful Bb and harmless soil-dwelling fungi, implying that fungi-regardless of their pathogenicity-signal habitat suitability to ticks. Only accessible Bb-inoculated substrate appealed to ticks, indicating that they sense Bb or its metabolites by contact chemoreception. Bb-inoculated substrate required ≥24 h of incubation before it appealed to ticks, suggesting that they respond to Bb metabolites rather than to Bb itself. Similarly, ticks responded to Bb-inoculated and incubated cellulose but not to sterile cellulose, indicating that Bb detection by ticks hinges on the Bb metabolism of cellulose. 2-Methylisoborneol-a common fungal metabolite with elevated presence in disturbed soils-strongly deterred ticks. Off-host ticks that avoid disturbed soil may lower their risk of physical injury. Synthetic 2-methylisoborneol could become a commercial tick repellent, provided its repellency extends to ticks in diverse taxa.

3.
R Soc Open Sci ; 11(1): 231355, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38179077

RESUMEN

Ticks spend most of their life inhabiting leaf litter and detritus where they are protected from sun but preyed upon by ants. Ants secrete chemical communication signals to coordinate group tasks such as nest defence. Ticks that avoid ant semiochemicals-as indicators of ant presence-would reduce predation risk by ants. We tested the hypotheses that: (i) chemical deposits from the thatching ant Formica oreas deter blacklegged ticks, Ixodes scapularis, (ii) deterrent semiochemicals originate from the ants' poison and/or Dufour's gland(s), and (iii) tick-deterrent semiochemicals serve as alarm-recruitment pheromone components in F. oreas. In two-choice olfactometer bioassays, filter paper soiled with ant chemical deposits significantly deterred female and male ticks. Poison and Dufour's gland extracts deterred ticks in combination but not alone. Gas chromatographic-mass spectrometric analyses of gland extracts revealed formic acid as the major constituent in the poison gland and eight hydrocarbons as constituents in the Dufour's gland. Synthetic formic acid and hydrocarbons deterred ticks only when combined. F. oreas workers sprayed both formic acid and hydrocarbons when distressed. A synthetic blend of these compounds elicited alarm-recruitment responses by F. oreas in behavioural bioassays. All results combined indicate that ticks eavesdrop on the ants' communication system.

4.
Sci Rep ; 14(1): 5727, 2024 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-38459134

RESUMEN

Few studies have investigated the relative contribution of specific nutrients to momentary and season-long foraging responses by ants. Using western carpenter ants, Camponotus modoc, and European fire ants, Myrmica rubra, as model species, we: (1) tested preferential consumption of various macro- and micro-nutrients; (2) compared consumption of preferred macro-nutrients; (3) investigated seasonal shifts (late May to mid-September) in nutrient preferences; and (4) tested whether nutrient preferences of C. modoc and M. rubra pertain to black garden ants, Lasius niger, and thatching ants, Formica aserva. In laboratory and field experiments, we measured nutrient consumption by weighing Eppendorf tubes containing aqueous nutrient solutions before and after feeding by ants. Laboratory colonies of C. modoc favored nitrogenous urea and essential amino acids (EAAs), whereas M. rubra colonies favored sucrose. Field colonies of C. modoc and M. rubra preferentially consumed EAAs and sucrose, respectively, with no sustained shift in preferred macro-nutrient over the course of the foraging season. The presence of a less preferred macro-nutrient in a nutrient blend did not diminish the blend's 'appeal' to foraging ants. Sucrose and EAAs singly and in combination were equally consumed by L. niger, whereas F. aserva preferred EAAs. Baits containing both sucrose and EAAs were consistently consumed by the ants studied in this project and should be considered for pest ant control.


Asunto(s)
Hormigas , Animales , Estaciones del Año , Hormigas/fisiología , Nutrientes , Sacarosa , Conducta Alimentaria
5.
Children (Basel) ; 11(3)2024 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-38539353

RESUMEN

BACKGROUND: Children's nutrition in Africa, especially among those displaced by conflicts, is a critical global health concern. Adequate nutrition is pivotal for children's well-being and development, yet those affected by displacement confront distinctive challenges. This scoping review seeks to enhance our current knowledge, filling gaps in understanding nutritional and associated health risks within this vulnerable population. OBJECTIVE: We conducted a scoping review of the literature on the nutritional status and associated health outcomes of this vulnerable population with the goal of informing targeted interventions, policy development, and future research efforts to enhance the well-being of African refugee and internally displaced children. METHODS: This scoping review adopted Arksey and O'Malley (2005)'s methodology and considered studies published between 2000 and 2021. RESULTS: Twenty-three published articles met the inclusion criteria. These articles highlighted a wide variation in the levels of malnutrition among African refugee/internally displaced (IDP) children, with the prevalence of chronic malnutrition (stunting) and acute malnutrition (wasting) ranging from 18.8 to 52.1% and 0.04 to 29.3%, respectively. Chronic malnutrition was of 'high' or 'very high' severity (according to recent WHO classifications) in 80% of studies, while acute malnutrition was of 'high' or 'very high' severity in 50% of studies. In addition, anemia prevalence was higher than the 40% level considered to indicate a severe public health problem in 80% of the studies reviewed. CONCLUSION: In many settings, acute, chronic, and micronutrient malnutrition are at levels of great concern. Many countries hosting large, displaced populations are not represented in the literature, and research among older children is also lacking. Qualitative and intervention-focused research are urgently needed.

6.
R Soc Open Sci ; 10(5): 230084, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37206969

RESUMEN

Foraging ticks reportedly exploit diverse cues to locate their hosts. Here, we tested the hypothesis that host-seeking Western black-legged ticks, Ixodes pacificus, and black-legged ticks, I. scapularis, respond to microbes dwelling in sebaceous gland secretions of white-tailed deer, Odocoileus virginianus, the ticks' preferred host. Using sterile wet cotton swabs, microbes were collected from the pelage of a sedated deer near forehead, preorbital, tarsal, metatarsal and interdigital glands. Swabs were plated on agar, and isolated microbes were identified by 16S rRNA amplicon sequencing. Of 31 microbial isolates tested in still-air olfactometers, 10 microbes induced positive arrestment responses by ticks, whereas 10 others were deterrent. Of the 10 microbes prompting arrestment by ticks, four microbes-including Bacillus aryabhattai (isolates A4)-also attracted ticks in moving-air Y-tube olfactometers. All four of these microbes emitted carbon dioxide and ammonia as well as volatile blends with overlapping blend constituents. The headspace volatile extract (HVE) of B. aryabhattai (HVE-A4) synergistically enhanced the attraction of I. pacificus to CO2. A synthetic blend of HVE-A4 headspace volatiles in combination with CO2 synergistically attracted more ticks than CO2 alone. Future research should aim to develop a least complex host volatile blend that is attractive to diverse tick taxa.

7.
Indian Pediatr ; 58(10): 932-935, 2021 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-33506809

RESUMEN

OBJECTIVE: To develop and apply a tool for measuring hospital discharge readiness of mothers practicing continuous kangaroo mother care (KMC) in a tertiary setting. METHODS: A 22-item questionnaire was adapted from an existing tool. After a pilot (n=20), the survey was administered to 200 mothers in the KMC unit, Kalafong Hospital, South Africa from 2017-2018. Two items which asked participants how confident and ready they felt overall were used to categorize women as 'ready' or 'less ready' for discharge. RESULTS: Most women (n=168, 88.0%) were categorized as ready for discharge. The mean (SD) score for all 22 questions was 9.4 (0.7). Women categorized as 'less ready' scored lower overall (mean difference: 1.3) and within all four questionnaire categories compared to women who were discharge ready (P<0.05). CONCLUSIONS: Although most women in this study reported high levels of discharge readiness, further research is needed to see if results are comparable across settings.


Asunto(s)
Método Madre-Canguro , Niño , Femenino , Hospitales , Humanos , Madres , Alta del Paciente , Encuestas y Cuestionarios
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