Genetic diversity is a key factor for population survival and evolution. However, anthropogenic habitat disturbance can erode it, making populations more prone to extinction. Aiming to assess the ...global effects of habitat disturbance on plant genetic variation, we conducted a meta‐analysis based on 92 case studies obtained from published literature. We compared the effects of habitat fragmentation and degradation on plant allelic richness and gene diversity (equivalent to expected heterozygosity) and tested whether such changes are sensitive to different life‐forms, life spans, mating systems, and commonness. Anthropogenic disturbance had a negative effect on allelic richness, but not on gene diversity. Habitat fragmentation had a negative effect on genetic variation, whereas habitat degradation had no effect. When we examined the individual effects in fragmented habitats, allelic richness and gene diversity decreased, but this decrease was strongly dependent on certain plant traits. Specifically, common long‐lived trees and self‐incompatible species were more susceptible to allelic richness loss. Conversely, gene diversity decreased in common short‐lived species (herbs) with self‐compatible reproduction. In a wider geographical context, tropical plant communities were more sensitive to allelic richness loss, whereas temperate plant communities were more sensitive to gene diversity loss. Our synthesis showed complex responses to habitat disturbance among plant species. In many cases, the absence of effects could be the result of the time elapsed since the disturbance event or reproductive systems favoring self‐pollination, but attention must be paid to those plant species that are more susceptible to losing genetic diversity, and appropriate conservation should be actions taken.
Meta‐Análisis de los Efectos Diferenciales de la Fragmentación y Degradación del Hábitat sobre la Diversidad Genética de las Plantas
Resumen
La diversidad genética es un factor clave para la supervivencia y evolución de las poblaciones. Sin embargo, la perturbación antropogénica de los hábitats puede dañar esta diversidad, volviendo a las poblaciones más susceptibles a la extinción. Con el objetivo de evaluar los efectos globales de la perturbación del hábitat sobre la variación genética de las plantas, realizamos un meta‐análisis basado en 92 estudios de caso obtenidos de la literatura publicada. Comparamos los efectos de la degradación y fragmentación del hábitat sobre la riqueza de alelos y la diversidad de genes (equivalente a la heterocigosidad esperada) de las plantas y probamos si dichos cambios son sensibles para diferentes formas de vida, tiempos de vida, sistemas de apareamiento y preponderancia. La perturbación antropogénica tuvo un efecto negativo sobre la riqueza de alelos, pero no sobre la diversidad genética. La fragmentación del hábitat tuvo un efecto negativo sobre la variación genética, mientras que la degradación del hábitat no tuvo efecto. Cuando examinamos los efectos individuales en los hábitats fragmentados, la riqueza de alelos y la diversidad genética disminuyeron, pero esta disminución estuvo vinculada fuertemente con ciertas características de las plantas. Específicamente, los árboles de larga vida y las especies auto‐incompatibles fueron más susceptibles a la pérdida de la riqueza de alelos. De manera contraria, la diversidad genética disminuyó en especies comunes de vida corta (hierbas) con reproducción auto‐compatibles. En un contexto geográfico más amplio, las comunidades de plantas tropicales fueron más sensibles a la pérdida de la riqueza de alelos, mientras que las comunidades de plantas de zonas templadas fueron más sensibles a la pérdida de diversidad de genes. Nuestra síntesis mostró respuestas complejas a la perturbación del hábitat entre las especies de plantas. En muchos casos, la ausencia de efectos podría ser el resultado del tiempo transcurrido desde el evento de perturbación o los sistemas reproductivos que favorecen la auto‐polinización, pero se le debe prestar atención a aquellas especies de plantas que son más susceptibles a la pérdida de la diversidad genética, para así poder realizar las acciones de conservación apropiadas.
摘要
遗传多样性是种群存活和演化的关键因素。然而, 人类对生境的干扰会侵蚀遗传多样性, 导致种群更容易灭绝。为了评估全球生境干扰对植物遗传变异的影响, 我们对 92 项已发表文献中的案例研究进行了荟萃分析。我们比较了生境破碎化和退化对植物等位基因丰富度和基因多样性 (相当于期望杂合度) 的影响, 并检验了植物的遗传多样性变化是否容易受到不同的生活型、寿命、繁殖方式和稀有性的影响。人类干扰对等位基因丰富度有负面影响, 但对基因多样性没有作用。生境破碎化对遗传变异有负面影响, 而生境退化则没有影响。我们检测了破碎化生境中影响因素的单独作用, 发现等位基因丰富度和基因多样性均下降, 但下降程度与植物的某些性状密切相关。具体来说, 寿命长的常见种和自交不亲和的物种更容易丧失等位基因丰富度。相反地, 寿命短的常见种 (草本植物) 与自交亲和的物种更容易发生基因多样性下降。在更广泛的地理环境中, 热带植物群落更可能丧失等位基因丰富度, 而温带植物群落则更可能丧失基因多样性。我们的总结表明不同植物对生境干扰表现出复杂的响应。在许多情况下, 没有观察到影响可能与干扰事件发生的时间有关, 或是因为该植物的繁殖方式倾向于自花授粉, 但必须注意那些对遗传多样性丧失更敏感的植物, 并采取适当的保护措施。【翻译: 胡怡思; 审校: 聂永刚】
Article impact statement: Effects of disturbance on plant genetic diversity are influenced by disturbance type, plant biological traits, and geographical context.
We assessed whether soil disturbance by agricultural activity influences the growth, development, and survival of individuals in the larval, metamorphic, and postmetamorphic stages of amphibians. ...Tadpoles of
Pithecopus azureus
(Cope, 1862) were reared in microcosms assembled with soil from two sites, a pristine site and a rice field. For 5 weeks, we recorded tadpole growth and development as well as physicochemical variable of the water: temperature, conductivity, dissolved oxygen, and pH. The results show that rice field soil produced a level of acidification in the water that influenced the growth and development rates of tadpoles. Tadpoles reared in rice soil had a significantly lower growth rate and body length, and during a specified period, the development rate of the tadpole was significantly lower than that of tadpoles in pristine soil. Overall, tadpoles in rice soil took 3 days longer to reach metamorphosis and 1 additional day to complete metamorphosis compared with tadpoles exposed to pristine soil. Our study shows that disturbed soils modify the physicochemical conditions of temporary ponds, impacting on the initial life stage of the anurans.
•Flightless steamer ducks preferred nesting on islets and along rocky coasts.•Upland geese preferred nesting in medium-dense shrubland.•Nest detection decreased with denser vegetation.•Invasive mink ...was present on 100 % of ten islets studied.•Interactive map for designing mink control actions.
The introduction of carnivores to islands affects the conservation status of native prey. For two decades, American mink (Neogale vison) has expanded its distribution in the sub-Antarctic archipelago of Austral Patagonia, while preying on nests of solitary ground-nesting birds. Here, upland geese (Chloephaga picta) and flightless steamer ducks (Tachyeres pteneres) are naïve to such predation risk because of the lack of native terrestrial predators. We used nest occupancy models to reveal preferred breeding habitats of those two ground-nesting waterbirds to prioritize areas for future mink control programs. We searched for nests along 80 transects on Navarino Island, southernmost Chile, and 11 transects on 10 nearby islets (3 ± 2.9 ha). Our results showed that islets were essential for breeding in comparison to the main island (5.3 nests/km versus 0.8 nests/km, respectively). The occupancy models revealed that islets were particularly important for flightless steamer ducks, endemic to western Patagonia. As breeding habitat, upland geese preferred medium-dense shrubland, and flightless steamer ducks preferred rocky coastlines. Nest detection was negatively affected by dense vegetation and, in the case of the upland geese, towards the end of the survey. Ten camera traps (n = 385 trap nights) revealed mink presence on all islets, highlighting their capacity to swim in cold water, up to 340 m distance from the main island. We conclude that islets represent breeding refuges for ground-nesting waterbirds and therefore advocate allocating resources for mink control during the warm season on islets. We also provide predictive maps of nesting habitat preference of upland geese and flightless steamer ducks for conservation managers to focus their often scarce human and financial resources on areas critical for breeding. Finally, we argue that detection probability should be an integral part of bird breeding studies, which can be methodologically achieved through targeting transects, not nests, as sample units.
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En las especies ectotérmicas, la temperatura es uno de los factores ambientales que más determinan el crecimiento, el desarrollo y la supervivencia. En especies con ciclos de vida complejos (e.g., ...anfibios), la supervivencia diferencial en distintas etapas de la vida puede conducir a patrones de variabilidad compleja, lo que afecta el tamaño y la estructura de las poblaciones. El objetivo de este estudio fue evaluar experimentalmente el efecto de la temperatura sobre la supervivencia, la tasa de crecimiento y el desarrollo en dos especies de larvas de anuros: Trachycephalus typhonius y Scinax nasicus. Durante 15 días se criaron 20 larvas de cada especie en cada uno de los cinco tratamientos: 26, 28, 30, 32 y 34 °C. Los resultados muestran que las larvas de S. nasicus son más susceptibles al efecto de la temperatura, y muestran menos supervivencia que las larvas de T. typhonius. A su vez, la supervivencia disminuye de manera marcada con el aumento de la temperatura; los individuos expuestos a 34 °C presentaron la menor supervivencia. La temperatura no indujo cambios significativos en las tasas de crecimiento y desarrollo de las larvas de T. typhonius, aunque se observa una tendencia a incrementar estos parámetros en las temperaturas intermedias, con valores más bajos en los extremos. En contraste, S. nasicus ven incrementadas significativamente sus tasas de crecimiento y desarrollo cuando se las cría a temperaturas elevadas. Los resultados demuestran que un incremento en la temperatura del ambiente, aún durante lapsos cortos, puede aumentar la tasa de crecimiento de las larvas de anfibios, acelerar su desarrollo y reducir su supervivencia, con un notable efecto especie-especifico.
Misinformation in Spanish on social media platforms has contributed to COVID-19 vaccine hesitancy among Latino parents. Brigada Digital de Salud was established to disseminate credible, science-based ...information about COVID-19 in Spanish on social media.
This study aims to assess participants' reactions to and engagement with Brigada Digital content that sought to increase COVID-19 vaccine uptake among US Latino parents and their children.
We conducted a 5-week intervention in a private, moderator-led Facebook (Meta Platforms, Inc) group with Spanish-speaking Latino parents of children aged ≤18 years (N=55). The intervention participants received 3 to 4 daily Brigada Digital posts and were encouraged to discuss the covered topics through comments and polls. To assess participants' exposure, reactions, and engagement, we used participants' responses to a web-based survey administered at 2 time points (baseline and after 5 weeks) and Facebook analytics to calculate the average number of participant views, reactions, and comments. Descriptive statistics were assessed for quantitative survey items, qualitative responses were thematically analyzed, and quotes were selected to illustrate the themes.
Overall, 101 posts were published. Most participants reported visiting the group 1 to 3 times (22/55, 40%) or 4 to 6 (18/55, 33%) times per week and viewing 1 to 2 (23/55, 42%) or 3 to 4 (16/55, 29%) posts per day. Facebook analytics validated this exposure, with 36 views per participant on average. The participants reacted positively to the intervention. Most participants found the content informative and trustworthy (49/55, 89%), easy to understand, and presented in an interesting manner. The participants thought that the moderators were well informed (51/55, 93%) and helpful (50/55, 91%) and praised them for being empathic and responsive. The participants viewed the group environment as welcoming and group members as friendly (45/55, 82%) and supportive (19/55, 35%). The 3 most useful topics for participants were the safety and efficacy of adult COVID-19 vaccines (29/55, 53%), understanding child risk levels (29/55, 53%), and the science behind COVID-19 (24/55, 44%). The preferred formats were educational posts that could be read (38/55, 69%) and videos, including expert (28/55, 51%) and instructional (26/55, 47%) interviews. Regarding engagement, most participants self-reported reacting to posts 1 to 2 (16/55, 29%) or 3 to 4 (15/55, 27%) times per week and commenting on posts 1 to 2 (16/55, 29%) or <1 (20/55, 36%) time per week. This engagement level was validated by analytics, with 10.6 reactions and 3 comments per participant, on average, during the 5 weeks. Participants recommended more opportunities for engagement, such as interacting with the moderators in real time.
With adequate intervention exposure and engagement and overall positive participant reactions, the findings highlight the promise of this digital approach for COVID-19 vaccine-related health promotion.
Aplectana hylambatis is a nematode with a wide geographic distribution and low host specificity. In spite of numerous reports, until this moment, the morphological variations between different hosts ...and localities have not been studied. We studied 401 specimens collected from five host species from seven localities in Argentina, and examined the following morphological characters: mamelon-like cuticular protuberances anterior to the vulva, structure of the gubernaculum and the spicules, number and arrangement of caudal papillae, and the measurements of twelve characters in females and eleven characters in males. The results showed that mamelon-like protuberances and caudal papillae varied in number and arrangement between different hosts and localities. The metrical study revealed that five characters in males and six in females contributed to variability; nine characters showed significant differences between host species and localities. Specimens of A. hylambatis collected from R. arenarum formed a group clearly differentiated from the rest of the specimens. The results from this study highlight the importance of examining as many specimens as possible from different host samples and from several localities to cover the intraspecific variations.
Cosmocercids are common nematodes that parasitize the digestive tract and lungs of amphibians and reptiles around the world. They are commonly found in leptodactylid and bufonid anurans in South ...America, primarily in Brazil and Argentina. This paper describes a new species of genus Cosmocerca based on specimens collected in a microhylid from the Dry Chaco ecoregion.
A total of 18 specimens of Elachistocleis haroi were collected in October 2011 in Chaco province and in December 2021 and March 2022 in Formosa province, Argentina, both areas of the Dry Chaco ecoregion. The morphology of the nematodes was studied in detail using light microscopy and scanning electron microscopy.
One hundred and fifty-one nematodes were collected from the large intestines of E. haroi. Based on the morphology of the caudal papillae (rosette papillae and plectanes), the presence of two spicules and the absence of caudal alae in males, and the presence of two prodelphic ovaries in females, these specimens were allocated to the genus Cosmocerca. However, they presented unique characteristics that differentiate them from all known species. Cosmocerca wichiorum sp. nov. is similar to C. archeyi, C. australis, C. sardiniae, C. zugi, and C. leytensis by having four pairs of plectanes, but can be easily distinguished from all of them by the type, number, and arrangement of the precloacal (non-plectanes), adcloacal and postcloacal papillae, by the length of the spicules and by its different zoogeographical distribution.
This is the 14th species of the genus Cosmocerca described in South America and the first one for the microhylid E. haroi from the Dry Chaco ecoregion.
is the etiological agent of toxoplasmosis. Mother-to-child transmission of this parasite can occur during pregnancy. Newborns with congenital toxoplasmosis may develop central nervous system ...impairment, with severity ranging from subclinical manifestations to death. A proinflammatory/regulated specific immune profile is crucial in the defense against the parasite; nevertheless, its role in the infected pregnant women and the congenitally infected offspring has been poorly explored, and there is still no consensus about its relation to parasite vertical transmission or to severity and dissemination in the congenitally infected newborns. This work aimed to characterize these relations by means of principal component and principal factor analyses. For this purpose, we determined the specific production of the four immunoglobulin G antibody subclasses, cytokines, and lymphocyte proliferation in the
infected pregnant women-10 who transmitted the infection to their offspring and seven who did not-as well as in 11 newborns congenitally infected and grouped according to disease severity (five mild and six moderate/severe) and dissemination (four local and seven disseminated). We found that the immune response of nontransmitter women differed from that of the transmitters, the latter having a stronger proinflammatory response, supporting a previous report. We also found that newborns who developed moderate/severe disease presented higher levels of lymphocyte proliferation, particularly of CD8
and CD19
cells, a high proportion of tumor necrosis factor α producers, and reduced expression of the immune modulator transforming growth factor β, as opposed to children who developed mild clinical complications. Our results suggest that a distinctive, not regulated, proinflammatory immune response might favor
vertical transmission and the development of severe clinical manifestations in congenitally infected newborns.
Persistent COVID is characterized by the presence of fatigue, mental fog, and sleep problems, among others. We aimed to study cognitive abilities (attention, executive functions, memory, language) ...and psychological and emotional factors in a group of participants of the population with persistent COVID-19 and asymptomatic or non-COVID-19-infected patients;
A total of 86 participants aged 18 to 66 years (X = 46.76) took part in the study, with 57 individuals (66.27%) in the experimental group and 29 (33.73%) in the control group. A comprehensive assessment included neuropsychological evaluations, evaluations of anxious and depressive symptomatology, assessments of the impact of fatigue, sleep quality, memory failures in daily life, and the perceived general health status of the participants;
significant differences between groups were found in incidental learning within the Key Numbers task (U = 462.5;
= 0.001;
= 0.022) and in the Direct Digit Span (U = 562;
= 0.022), but not in the Inverse Digit Span (U = 632.5;
= 0.105). Differences were also observed in the prospective memory task of the Rivermead Prospective Memory Tasks (from the Rivermead Behavioural Memory Test) in the recall of quotations (U = 610;
= 0.020) as well as in the recall of objects (U = 681.5;
= 0.032). Concerning the task of verbal fluency, significant differences were found for both phonological cues (
- and s-) (t = -2.190;
= 0.031) and semantic cues (animals) (t = -2.277;
= 0.025). In terms of the psychological impact assessment, significant differences were found in the emotional impact across all variables studied (fatigue, quality of sleep, memory lapses, and the perceived general health status), except for quality of life;
Our results suggest that the sequelae derived from persistent COVID may have an impact on people's lives, with higher levels of anxiety and depression, worse sleep quality, a greater number of subjective memory complaints, and a greater feeling of fatigue and impact on quality of life. Furthermore, poorer performance was observed in memory and verbal fluency.
Desiccation exposes tadpoles to a decrease in habitat size due to a reduction in water depth and surface area. We tested the effect of surface area and water depth on growth and development of ...tadpoles of Physalaemus albonotatus and whether habitat size effects are constant over the larval period. We performed a 2 × 2 factorial design: two water depths and two surface areas. We measured tadpoles at 15 and 30 days after starting the experiment, and recorded weight and time to metamorphosis. Our results indicate that habitat size influences the morphology, growth, and development of tadpoles and that the response changes during development. At 15 days, tadpoles reared in shallow water had reduced their morphological variables and developmental stage, whereas tadpoles reared in enclosures with different surface areas showed no differences. At 30 days, tadpoles reared in enclosures with small surface areas had increased their body length, body height, and developmental stage, whereas tadpoles reared in different water depths showed no differences. Tadpoles reared in small surface areas reached metamorphosis earlier than tadpoles reared in large surface areas. The results suggest that during ontogeny the surface area and water depth had different influence in the phenotypic plasticity of tadpoles.
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