Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Environ Pollut ; 356: 124316, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38848955

RESUMO

Soil heavy metal contamination is often an unintended byproduct of historic land-use. This contamination can negatively impact resident plants and their interactions with other organisms. Plant fitness in contaminated landscapes depends not only on plant growth, but also on the maintenance of interactions with pollinators. Cadmium (Cd) is a heavy metal that is commonly found in agricultural, urban, and industrial ecosystems as a legacy of historic land-use. It is a prioritized pollutant in soils because of its wide distribution and strong biotoxicity. To understand how Cd influences plant growth and pollinator interactions, we grew sunflowers in media with three different Cd concentrations to represent the range of Cd contamination faced by sunflowers growing on land recovering from past land-use. We measured Cd contamination effects on sunflower morphology and pollinator foraging behavior, specifically the number of visits and visit duration. We then measured seed number and weight to determine if contamination directly or indirectly, as mediated by pollinators, altered plant fitness. Plant height was negatively correlated with Cd concentration, but contamination alone (in the absence of pollinators) did not affect sunflower reproduction. Bumble bees visited sunflowers grown in Exceeding Threshold Cd concentrations less often and for shorter time compared to visits to Below Threshold Cd sunflowers, but honey bees and sweat bees showed similar foraging behavior across Cd contamination treatment levels. Sunflower seed set was positively correlated with the total number of pollinator visits, and sunflowers grown in Exceeding Threshold Cd soil had marginally lower seed set compared to those grown in Below Threshold Cd soil. Our results suggest that at Exceeding Threshold Cd contamination levels plant-pollinator interactions are negatively affected with consequences for plant fitness.


Assuntos
Cádmio , Helianthus , Polinização , Poluentes do Solo , Poluentes do Solo/análise , Cádmio/análise , Abelhas/fisiologia , Abelhas/efeitos dos fármacos , Helianthus/efeitos dos fármacos , Helianthus/fisiologia , Helianthus/crescimento & desenvolvimento , Animais , Solo/química
2.
Front Glob Womens Health ; 4: 1053541, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36925643

RESUMO

Objective: Repeat urgent cesarean sections (CS) carry an increased risk of severe maternal outcomes. As CS increase in sub-Saharan Africa, creative strategies are necessary to reduce the rate of urgent repeat CS. The Zigama-Mama Project in rural Burundi uses complimentary ultrasounds to create a clinical touchpoint to counsel women with a prior CS for a hospital-based delivery. Methods: From July 2019 to June 2020, complimentary ultrasounds were offered to all antenatal patients with prior CS, along with counseling for monitored trial of labor after cesarean (TOLAC) or scheduled repeat CS. Community engagement and feedback from district health centers were evaluated. Results: In total, 500 women with a prior CS presented for a complimentary ultrasound. During the intervention year, a relative and absolute reduction in urgent repeat CS (baseline: n = 114 {70.8%}, intervention: n = 97{49.7%}, p < 0.001) was observed, with no significant change in maternal mortality or ruptured uteri. All health center personnel agreed the project improved their confidence in referring women with prior CS. Conclusion: Offering complimentary ultrasounds as a clinical touchpoint for scheduling a monitored delivery or CS for women at high risk for delivery complication may be an affordable and creative strategy to care for women with previous CS during subsequent deliveries.

3.
Environ Entomol ; 51(2): 471-481, 2022 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-35020889

RESUMO

Since 2000, wild black cherry (Prunus serotina Ehrh.) has produced erratic seed crops, especially in the Allegheny National Forest where poor seed production has been implicated in difficulties with black cherry regeneration in forest stands. Given that black cherry is insect pollinated and unable to produce viable seed from self-pollination, a reduction in seed crops could be due to a pollination deficit; however, its key pollinators are unknown. Identifying the pollinators and factors that influence pollinator abundance and fidelity is critical for supporting and enhancing seed production for this valuable timber species. Over a two-year period in developed, semideveloped, and forested areas in Pennsylvania, we identified the potential pollinators of black cherry and examined how their abundance, along with several other abiotic and biotic factors, influenced viable seed production. We found that andrenid (Andrenidae: Hymenoptera) bees are likely the most important pollinators. The proportion of viable seeds increased as the number of andrenids increased, and these ground nesting bees were most abundant on forest edges, highlighting this habitat's potential to support pollination services. Andrenids carried an average of 347-fold more black cherry pollen than flies and 18-fold more than halictid (Halictidae: Hymenoptera) bees. We did not find a significant relationship between the abundance of any other taxa besides andrenids and viable seed production. Black cherry flowers also provide resources for natural enemies such as the economically important parasitoid of Popillia japonica Newman (Scarabaeidae: Coleoptera), Tiphia vernalis Rohwer (Tiphiidae: Hymenoptera), which was observed feeding on black cherry nectar in this study.


Assuntos
Besouros , Himenópteros , Prunus avium , Rosaceae , Rosales , Animais , Abelhas , Produtos Agrícolas , Flores , Insetos , Polinização , Sementes
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA