Irregular red blood cell antibodies, abnormal hemoglobin and dangerous universal blood donor insights from a public blood center in a Brazilian metropolitan area.

BACKGROUND: Immunohematology tests are crucial in transfusion safety. This study aimed to assess irregular red blood cell (RBC) antibodies, abnormal hemoglobin and dangerous universal blood donors at a public blood center in a Brazilian metropolitan area. METHODS: A cross-sectional study included all consecutive blood donors from January 2018 to December 2021 at the Brasília Blood Center Foundation, Federal District (FD), Brazil. RESULTS: Among 205,965 blood donations, irregular RBC antibodies were found in 743 (0.4 %). Abnormal hemoglobin was observed in 5396 (2.6 %): 3959 (1.9 %) with Hb AS, 1344 (0.7 %) with Hb AC, and 93 (< 0,1 %) with other hemoglobin variants. Of O group donors, 12.5 % (9646) had hemolysins: 12.5 % (2410) both anti-A and anti-B, 8.7 % (9646) only anti-A, and 1.6 % (1763) only anti-B hemolysins. Female sex (p < 0.001) and increasing age (p < 0.001) were associated with irregular RBC antibodies. O and/or Rh(D)-positive blood groups had a lower prevalence of irregular RBC antibodies compared to other ABO and/or Rh(D)-negative groups. Age (p < 0.001) and female sex (p < 0.001) were associated with anti-A/anti-B hemolysins, while FD residency was associated with reduced incidence (p < 0.001). CONCLUSION: Anti-A/anti-B hemolysins in O group donors, abnormal hemoglobin and irregular RBC antibodies pose risks to transfusion practice and should not be overlooked. Advancing age, female sex, ABO blood group other than O, or Rh(D)- negative are independently associated with the presence of irregular RBC antibodies. Dangerous universal blood donors were associated with advanced age, female gender, Rh(D)-positive blood type, and individuals residing in a Brazilian state other than where the blood center was located.

How many animal-pollinated angiosperms are nectar-producing?

The diversity of plant-pollinator interactions is grounded in floral resources, with nectar considered one of the main floral rewards plants produce for pollinators. However, a global evaluation of the number of animal-pollinated nectar-producing angiosperms and their distribution world-wide remains elusive. We compiled a thorough database encompassing 7621 plant species from 322 families to estimate the number and proportion of nectar-producing angiosperms reliant on animal pollination. Through extensive sampling of plant communities, we also explored the interplay between nectar production, floral resource diversity, latitudinal and elevational gradients, contemporary climate, and environmental characteristics. Roughly 223 308 animal-pollinated angiosperms are nectar-producing, accounting for 74.4% of biotic-pollinated species. Global distribution patterns of nectar-producing plants reveal a distinct trend along latitudinal and altitudinal gradients, with increased proportions of plants producing nectar in high latitudes and altitudes. Conversely, tropical communities in warm and moist climates exhibit greater floral resource diversity and a lower proportion of nectar-producing plants. These findings suggest that ecological trends driven by climate have fostered the diversification of floral resources in warmer and less seasonal climates, reducing the proportion of solely nectar-producing plants. Our study provides a baseline for understanding plant-pollinator relationships, plant diversification, and the distribution of plant traits.

Amazon tropical fishes of commercial interest show human-cell contamination but no SARS-CoV-2 in a real-life scenario.

BACKGROUND: Amazonas was one of the most impacted Brazilian states by the COVID-19 pandemic. Mortality rates were high, and the health systems collapsed. It is important to identify possible intermediate reservoirs to avoid animal-to-human contamination. Several tropical fish are of commercial interest and are sold in large open-air markets in the region, representing a large economic and dietary importance. OBJECTIVES: This study aimed to verify if fish species of commercial importance, aerosols, and fish wastewater in local open-air markets, at a major capital city in the western Brazilian Amazon, are contaminated by SARS-CoV-2. METHODS: 488 fish, 50 aerosol, and 45 wastewater samples were analyzed for the presence of SARS-CoV-2. The samples were subjected to extraction using the BIOGENE Viral DNA/RNA Extraction kit, and the molecular diagnosis was tested for SARS-CoV-2 using the Bio-Manguinhos SARS-CoV-2 (EDx) Molecular Kit. RESULTS: It was not possible to detect the virus (Ct≤40, for Gene E) in these samples, however, in 181 samples of fish it was possible to detect the human RP gene (Ct≤35, for the RP Gene), indicating human contact. There was a high number of COVID-19 diagnoses in all city districts in which the samples were collected, showing that SARS-CoV-2 was circulating. CONCLUSION: This study indicates that fish of local commercial importance do not carry SARS-CoV-2 viral particles, despite circulation of SARS-CoV-2, and are not an important source of animal-to-human contamination. Despite these results, the human RP gene was found detectable in fish, air, and fish wastewater, showing that such places may carry human pathogens.

Anatomical, histochemical, and developmental approaches reveal the long-term functioning of the floral nectary in Tocoyena formosa (Rubiaceae).

Tocoyena formosa has a persistent floral nectary that continues producing nectar throughout flower and fruit development. This plant also presents an intriguing non-anthetic nectary derived from early-developing floral buds with premature abscised corolla. In this study, we characterize the structure, morphological changes, and functioning of T. formosa floral nectary at different developmental stages. We subdivided the nectary into four categories based on the floral and fruit development stage at which nectar production started: (i) non-anthetic nectary; (ii) anthetic nectary, which follows the regular floral development; (iii) pericarpial nectary, derived from pollinated flowers following fruit development; and (iv) post-anthetic nectary that results from non-pollinated flowers after anthesis. The nectary has a uniseriate epidermis with stomata, nectariferous parenchyma, and vascular bundles, with a predominating phloem at the periphery. The non-anthetic nectary presents immature tissues that release the exudate. The nectary progressively becomes more rigid as the flower and fruit develop. The main nectary changes during flower and fruit development comprised the thickening of the cuticle and epidermal cell walls, formation of cuticular epithelium, and an increase in the abundance of calcium oxalate crystals and phenolic cells near the vascular bundles. Projections of the outer periclinal walls toward the cuticle in the post-anthetic nectary suggest nectar reabsorption. The anatomical changes of the nectary allow it to function for an extended period throughout floral and fruit development. Hence, T. formosa nectary is a bivalent secretory structure that plays a crucial role in the reproductive and defensive interactions of this plant species.

Effects of Isocaloric Resistance, Aerobic, and Concurrent Exercise on Excess Postexercise Oxygen Consumption in Older Adults.

ABSTRACT: Pilon, R, Matos-Santos, L, Matlez, MP, Rodrigues, G, Amorim, F, Lattari, E, Farinatti, P, and Monteiro, W. Effects of isocaloric resistance, aerobic, and concurrent exercise on excess postexercise oxygen consumption in older adults. J Strength Cond Res 38(4): 755-761, 2024-Excess postexercise oxygen consumption (EPOC) is a major determinant of exercise-related caloric expenditure and metabolic adaptations. Exercise modality may influence the EPOC, but this issue has not been investigated in older adults. This study compared the EPOC after isocaloric bouts of continuous aerobic exercise (AE), resistance exercise (RE), and concurrent exercise (CE) in older individuals. Ten subjects (5 men; 73 ± 6 years) had their cardiorespiratory data assessed during AE, RE, and CE and along 30-minute postexercise recovery. Total energy expenditure (EE) during exercise was similar (p > 0.05) in AE (126.0 ± 30.7 kcal), RE (123.9 ± 30.6 kcal), and CE (130.8 ± 32.6 kcal), with different times to achieve the targeted EE (RE: 61.4 ± 1.9 minutes > CE: 43.3 ± 5.6 minutes > AE: 26.6 ± 5.7 minutes; p < 0.001). Consistently, the relative intensity during exercise was superior (p < 0.05) in AE (74 ± 15% oxygen uptake reserve [VO2R]) vs. CE (43 ± 13% VO2R) vs. RE (24 ± 9% VO2R). Despite the isocaloric conditions, average EPOC and EE were approximately 45% greater (p < 0.001) in AE (8.0 ± 2.3 L; 40.1 ± 11.7 kcal) vs. RE (5.6 ± 1.2 L; 28.1 ± 5.8 kcal) and CE (5.4 ± 2.3 L; 26.9 ± 11.5 kcal). In conclusion, the EPOC was greater after isocaloric AE vs. RE and CE performed by older adults. Exercise intensity seemed to be a more important determinant of EPOC than volume reflected by EE during exercise bouts. Moderate-intensity continuous AE was more time-efficient than RE and CE to achieve a target EE. In older individuals, AE should be preferred over RE or CE when the purpose is to increase the daily caloric expenditure.

Imprints of indirect interactions on a resource-mediated ant-plant network across different levels of network organization.

Indirect interactions are pivotal in the evolution of interacting species and the assembly of populations and communities. Nevertheless, despite recently being investigated in plant-animal mutualism at the community level, indirect interactions have not been studied in resource-mediated mutualisms involving plant individuals that share different animal species as partners within a population (i.e., individual-based networks). Here, we analyzed an individual-based ant-plant network to evaluate how resource properties affect indirect interaction patterns and how changes in indirect links leave imprints in the network across multiple levels of network organization. Using complementary analytical approaches, we described the patterns of indirect interactions at the micro-, meso-, and macro-scale. We predicted that plants offering intermediate levels of nectar quantity and quality interact with more diverse ant assemblages. The increased number of ant species would cause a higher potential for indirect interactions in all scales evaluated. We found that nectar properties modified patterns of indirect interactions of plant individuals that share mutualistic partners, leaving imprints across different network scales. To our knowledge, this is the first study tracking indirect interactions in multiple scales within an individual-based network. We show that functional traits of interacting species, such as nectar properties, may lead to changes in indirect interactions, which could be tracked across different levels of the network organization evaluated.

Hyperoxemia Induced by Oxygen Therapy in Nonsurgical Critically Ill Patients.

BACKGROUND: Hyperoxemia, often overlooked in critically ill patients, is common and may have adverse consequences. OBJECTIVE: To evaluate the incidence of hyperoxemia induced by oxygen therapy in nonsurgical critically ill patients at intensive care unit (ICU) admission and the association of hyperoxemia with hospital mortality. METHODS: This prospective cohort study included all consecutive admissions of nonsurgical patients aged 18 years or older who received oxygen therapy on admission to the Hospital Santa Luzia Rede D'Or São Luiz adult ICU from July 2018 through June 2021. Patients were categorized into 3 groups according to Pao2 level at ICU admission: hypoxemia (Pao2<60 mm Hg), normoxemia (Pao2= 60-120 mm Hg), and hyperoxemia (Pao2 >120 mm Hg). RESULTS: Among 3088 patients, hyperoxemia was present in 1174 (38.0%) and was independently associated with hospital mortality (odds ratio [OR], 1.32; 95% CI, 1.04-1.67; P=.02). Age (OR, 1.02; 95% CI, 1.02-1.02; P<.001) and chronic kidney disease (OR, 1.55; 95% CI, 1.02-2.36; P=.04) were associated with a higher rate of hyperoxemia. Factors associated with a lower rate of hyperoxemia were Sequential Organ Failure Assessment score (OR, 0.88; 95% CI, 0.83-0.93; P<.001); late-night admission (OR, 0.80; 95% CI, 0.67-0.96; P=.02); and renal/metabolic (OR, 0.22; 95% CI, 0.13-1.39; P<.001), neurologic (OR, 0.02; 95% CI, 0.01-0.05; P<.001), digestive (OR, 0.23; 95% CI, 0.13-0.41; P<.001), and soft tissue/skin/orthopedic (OR, 0.32; 95% CI, 0.13-0.79; P=.01) primary reasons for hospital admission. CONCLUSION: Hyperoxemia induced by oxygen therapy was common in critically ill patients and was linked to increased risk of hospital mortality. Health care professionals should be aware of this condition because of its potential risks and unnecessary costs.

Predicting the Mpemba effect using machine learning.

The Mpemba effect can be studied with Markovian dynamics in a nonequilibrium thermodynamics framework. The Markovian Mpemba effect can be observed in a variety of systems including the Ising model. We demonstrate that the Markovian Mpemba effect can be predicted in the Ising model with several machine learning methods: the decision tree algorithm, neural networks, linear regression, and nonlinear regression with the least absolute shrinkage and selection operator (LASSO) method. The positive and negative accuracy of these methods are compared. Additionally, we find that machine learning methods can be used to accurately extrapolate to data outside the range in which they were trained. Neural networks can even predict the existence of the Mpemba effect when they are trained only on data in which the Mpemba effect does not occur. This indicates that information about which coefficients result in the Mpemba effect is contained in coefficients where the results does not occur. Furthermore, neural networks can predict that the Mpemba effect does not occur for positive J, corresponding to the ferromagnetic Ising model even when they are only trained on negative J, corresponding to the antiferromagnetic Ising model. All of these results demonstrate that the Mpemba effect can be predicted in complex, computationally expensive systems, without explicit calculations of the eigenvectors.

A new seed-feeding species of Hemicolpus Heller, 1895 from south Brazil and redescription of Hemicolpus abdominalis Hustache, 1938 (Coleoptera: Curculionidae: Conoderinae).

The genus Hemicolpus Heller, 1895 (Curculionidae: Conoderinae) currently includes six species: H. cubicus (Lacordaire) (Brazil); H. heteromorphus Hustache (Brazil); H. abdominalis Hustache (Bolivia, Brazil, and Paraguay); H. costaricensis Hespenheide (Costa Rica); H. randiae Hespenheide (El Salvador and Mexico) and H. prenai Hespenheide (El Salvador and Mexico). The known species are predispersal seed predators whose larvae feed and develop within fruits of Rubiaceae. Species from Central America have been reared from the fruits of Randia L. (Rubiaceae). In contrast, the only host plant known for the South American species, H. abdominalis, is Tocoyena formosa (Cham. & Schltdl.) K. Schum. (Rubiaceae), a plant species widely distributed in the Cerrado biome, occurring from southeast to north and northeast of Brazil. Here, we describe a seventh species of Hemicolpus, H. maragatensis Sanz-Veiga, Savaris & Leivas, sp. nov., morphologically close to H. abdominalis, associated with fruits of Randia ferox (Cham. & Schltdl.) DC. in the south of Brazil. Furthermore, we designate a lectotype and provide a redescription of H. abdominalis, including additional characters to differentiate it from H. maragatensis. For both species, we provide morphological descriptions of external and internal characters, including male and female genitalia illustrations, distribution data, and notes on the biology and host plant. A barcode region of the mitochondrial DNA is also included for both species adding genetic information to the species characterization and differentiation. We also provide an identification key for the species of the genus.

Multidrug-Resistant Bacteria on Critically Ill Patients with Sepsis at Hospital Admission: Risk Factors and Effects on Hospital Mortality.

Purpose: To evaluate the effect of MDRO infection on hospital mortality and the risk factors among critically ill patients with sepsis at hospital admission. Patients and Methods: A cross-sectional study was performed between April 2019 and May 2020, followed by a cohort to evaluate hospital mortality that prospectively included all consecutive patients 18 years or older with sepsis admitted within 48 hours of hospital admission to an adult ICU in Brazil. Patients' characteristics, blood samples within one hour of ICU admission, and microbiological results within 48h of hospital admission were collected. In addition, descriptive statistics, binary logistic regression, and propensity score matching were performed. Results: At least one MDRO was isolated in 85 patients (9.8%). The extended-spectrum beta-lactamase-producing Enterobacterales are the most frequent organism (56.1%). Hypoxemic acute respiratory failure (OR 1.87, 95% CI 1.02-3.40, p = 0.04), Glasgow Coma Score below 15 (OR 2.57, 95% CI 1.38-4.80, p < 0.01), neoplasm (OR 2.66, 95% CI 1.04-6.82, p = 0.04) and hemoglobin below 10.0 g/dL (OR 1.82, 95% CI 1.05-3.16, p = 0.03) were associated with increased MDRO. Admission from the Emergency Department (OR 0.25, 95% CI 0.14-0.43, p < 0.01) was associated with decreased MDRO. In the multivariate analysis, MDRO at hospital admission increased hospital mortality (OR 2.80, 95% CI 1.05-7.42, p = 0.04). After propensity score-matching adjusted to age, APACHE II, SOFA, and dementia, MDRO at hospital admission was associated with significantly high hospital mortality (OR 2.80, 95% CI 1.05-7.42, p = 0.04). The E-value of adjusted OR for the effect of MDRO infection on hospital mortality was 3.41, with a 95% CI of 1.31, suggesting that unmeasured confounders were unlikely to explain the entirety of the effect. Conclusion: MDRO infection increased hospital mortality, and MDRO risk factors should be accessed even in patients admitted to ICU within 48 hours of hospital admission.

Atlantic flower-invertebrate interactions: A data set of occurrence and frequency of floral visits.

Encounters between flowers and invertebrates are key events for the functioning of tropical forests. Assessing the structure of networks composed of the interactions between those partners leads to a better understanding of ecosystem functioning and the effects of environmental factors on ecological processes. Gathering such data is, however, costly and time-consuming, especially in the highly diverse tropics. We aimed to provide a comprehensive repository of available flower-invertebrate interaction information for the Atlantic Forest, a South American tropical forest domain. Data were obtained from published works and "gray literature," such as theses and dissertations, as well as self-reports by co-authors. The data set has ~18,000 interaction records forming 482 networks, each containing between one and 1061 interaction links. Each network was sampled for about 200 h or less, with few exceptions. A total of 641 plant genera within 136 different families and 39 orders were reported, with the most abundant and rich families being Asteraceae, Fabaceae, and Rubiaceae. Invertebrates interacting with these plants were all arthropods from 10 orders, 129 families, and 581 genera, comprising 2419 morphotypes (including 988 named species). Hymenoptera was the most abundant and diverse order, with at least six times more records than the second-ranked order (Lepidoptera). The complete data set shows Hymenoptera interacting with all plant orders and also shows Diptera, Lepidoptera, Coleoptera, and Hemiptera to be important nodes. Among plants, Asterales and Fabales had the highest number of interactions. The best sampled environment was forest (~8000 records), followed by pastures and crops. Savanna, grasslands, and urban environments (among others) were also reported, indicating a wide range of approaches dedicated to collecting flower-invertebrate interaction data in the Atlantic Forest domain. Nevertheless, most reported data were from forest understory or lower strata, indicating a knowledge gap about flower-invertebrate interactions at the canopy. Also, access to remote regions remains a limitation, generating sampling bias across the geographical range of the Atlantic Forest. Future studies in these continuous and hard-to-access forested areas will yield important new information regarding the interactions between flowers and invertebrates in the Atlantic Forest. There are no copyright restrictions on the data set. Please cite this data paper if the data are used in publications and teaching events.

Ontogenetic niche specialization of the spider crab Libinia ferreirae associated with the medusa Lychnorhiza lucerna.

Symbiotic relationships in marine environments are not fixed and can change throughout the animal's life. This study investigated the ontogeny of symbiosis of the spider crab Libinia ferreirae with the host medusa Lychnorhiza lucerna. We described the type of relationship, the temporal correlation among species, and food habits. More than 50% of the sampled crabs were symbionts, most in early life stages. The highest number of crabs found in a single medusa was 11. Symbiosis was observed throughout most of the year but was more evident in warm periods. The crab has many benefits in this relationship with a medusa. One is the use of food resources captured by the medusa, primarily copepods. Because the crab steals the medusa's food, it is a kleptoparasitic relationship. There is a niche partition between symbiont and the free-living crabs as they occupy different habitats and use nonoverlapping food resources. Previous research reported that symbiosis first developed during the crab's last larval phase (megalopa) when crab and medusa are in the same habitat. Observation of the crab's behavior shows that symbiosis occurs when the crab can grab to the medusa when the host touches the sea bottom. The crab also took advantage of water currents, releasing itself from the substrate and then drifting toward the medusa. The symbiotic relationship that crabs have with the medusa provides then with a nursery, food resources, shelter, dispersion, and decreased competition with free-living adult crabs, all essential for the crab's survival.

Data standardization of plant-pollinator interactions.

BACKGROUND: Animal pollination is an important ecosystem function and service, ensuring both the integrity of natural systems and human well-being. Although many knowledge shortfalls remain, some high-quality data sets on biological interactions are now available. The development and adoption of standards for biodiversity data and metadata has promoted great advances in biological data sharing and aggregation, supporting large-scale studies and science-based public policies. However, these standards are currently not suitable to fully support interaction data sharing. RESULTS: Here we present a vocabulary of terms and a data model for sharing plant-pollinator interactions data based on the Darwin Core standard. The vocabulary introduces 48 new terms targeting several aspects of plant-pollinator interactions and can be used to capture information from different approaches and scales. Additionally, we provide solutions for data serialization using RDF, XML, and DwC-Archives and recommendations of existing controlled vocabularies for some of the terms. Our contribution supports open access to standardized data on plant-pollinator interactions. CONCLUSIONS: The adoption of the vocabulary would facilitate data sharing to support studies ranging from the spatial and temporal distribution of interactions to the taxonomic, phenological, functional, and phylogenetic aspects of plant-pollinator interactions. We expect to fill data and knowledge gaps, thus further enabling scientific research on the ecology and evolution of plant-pollinator communities, biodiversity conservation, ecosystem services, and the development of public policies. The proposed data model is flexible and can be adapted for sharing other types of interactions data by developing discipline-specific vocabularies of terms.

Fotoproteção em Agentes Comunitários de Saúde (ACS) de Belém-PA / Photoprotection of Community Health Workers (CHW) of Belém-PA / Fotoprotección en Agentes Comunitarios de Salud (ACS) de Belém-PA

Objetivo: Avaliar a fotoproteção dos Agentes Comunitários de Saúde (ACS) de 5 equipes da Estratégia Saúde da Família. Métodos: A casuística consistiu em 56 ACS, os quais foram submetidos a um questionário autoaplicável com perguntas sobre os hábitos de exposição solar e os conhecimentos acerca do assunto. Resultados: Verificou-se que 48,2% dos ACS se expunham ao sol durante 2 a 6 horas entre segunda e sexta-feira e que 55,4% deles tinham exposição entre 10 e 15 horas. Além disso, 58,9% dos ACS utilizam filtros solares raramente ou nunca e, entre esses, 53,6% os aplicam com frequência inadequada. Contudo, 100% dos pesquisados relataram conhecer as consequências negativas da exposição solar. Conclusão: A fotoproteção dos ACS foi considerada inadequada, já que poucos utilizam filtros solares e os que relataram o uso do produto o faziam de maneira inapropriada. Ademais, o conhecimento sobre os riscos e as consequências da exposição solar foi considerado excelente.

Objective: To evaluate the photoprotection of Community Health Agents (CHA) in five health units. Methods: A casuistry of 56 CHA was used, which were submitted to a self-administered questionnaire with questions about their solar exposure habits and their knowledge about this subject matter. Results: From the analysis of the obtained data, it was verified that 48.2% CHA exposed themselves to the sun during 2 to 6 hours between Monday and Friday and that 55.4% of them are exposed between 10 AM and 3 PM. Furthermore, 58.9% of CHA rarely or never use solar filters and among them, 53.6% apply the product with an inappropriate frequency. However, 100% of the CHA reported to know about the negative consequences and the risks of the solar exposure. Conclusion: The agents' photoprotection was considered inappropriate, since just a few of them use solar filters and the ones, which reported using the product, do it improperly. Besides that, their knowledge about the risks and consequences of the solar exposure was considered excellent.

Objetivo: Evaluar la fotoprotección de los Agentes Comunitarios de Salud (ACS) de cinco unidades estudiadas. Métodos: La casuística consistió en 56 ACS, los cuales han sido sometidos a un cuestionario autoaplicable con preguntas sobre los hábitos de exposición solar y los conocimientos sobre el asunto. Resultados: Se verificó que el 48,2% de los ACS se exponían al sol durante 2 a 6 horas entre el lunes y el viernes y que el 55,4% de ellos se exponen entre las 10 de la mañana y 3 de la tarde. Además, el 58,9% de los ACS utilizan filtros solares raramente o nunca, y, entre ellos, 53,6% los aplican con frecuencia inadecuada. Sin embargo, el 100% de los entrevistados relataron conocer las consecuencias negativas de la exposición al sol. Conclusión: La fotoprotección de los ACS fue considerada inadecuada, en razón de la poca utilización de filtros solares y los que relataron el uso del producto lo hacían de manera inadecuada. Además, el conocimiento sobre los riesgos y las consecuencias de la exposición solar fue considerado excelente.

The diversity and evolution of pollination systems in large plant clades: Apocynaceae as a case study.

Background and Aims: Large clades of angiosperms are often characterized by diverse interactions with pollinators, but how these pollination systems are structured phylogenetically and biogeographically is still uncertain for most families. Apocynaceae is a clade of >5300 species with a worldwide distribution. A database representing >10 % of species in the family was used to explore the diversity of pollinators and evolutionary shifts in pollination systems across major clades and regions. Methods: The database was compiled from published and unpublished reports. Plants were categorized into broad pollination systems and then subdivided to include bimodal systems. These were mapped against the five major divisions of the family, and against the smaller clades. Finally, pollination systems were mapped onto a phylogenetic reconstruction that included those species for which sequence data are available, and transition rates between pollination systems were calculated. Key Results: Most Apocynaceae are insect pollinated with few records of bird pollination. Almost three-quarters of species are pollinated by a single higher taxon (e.g. flies or moths); 7 % have bimodal pollination systems, whilst the remaining approx. 20 % are insect generalists. The less phenotypically specialized flowers of the Rauvolfioids are pollinated by a more restricted set of pollinators than are more complex flowers within the Apocynoids + Periplocoideae + Secamonoideae + Asclepiadoideae (APSA) clade. Certain combinations of bimodal pollination systems are more common than others. Some pollination systems are missing from particular regions, whilst others are over-represented. Conclusions: Within Apocynaceae, interactions with pollinators are highly structured both phylogenetically and biogeographically. Variation in transition rates between pollination systems suggest constraints on their evolution, whereas regional differences point to environmental effects such as filtering of certain pollinators from habitats. This is the most extensive analysis of its type so far attempted and gives important insights into the diversity and evolution of pollination systems in large clades.

Pericarpial nectary-visiting ants do not provide fruit protection against pre-dispersal seed predators regardless of ant species composition and resource availability.

Extrafloral nectaries can occur in both vegetative and reproductive plant structures. In many Rubiaceae species in the Brazilian Cerrado, after corolla abscission, the floral nectary continues to secret nectar throughout fruit development originating post-floral pericarpial nectaries which commonly attract many ant species. The occurrence of such nectar secreting structures might be strategic for fruit protection against seed predators, as plants are expected to invest higher on more valuable and vulnerable parts. Here, we performed ant exclusion experiments to investigate whether the interaction with ants mediated by the pericarpial nectaries of Tocoyena formosa affects plant reproductive success by reducing the number of pre-dispersal seed predators. We also assessed whether ant protection was dependent on ant species composition and resource availability. Although most of the plants were visited by large and aggressive ant species, such as Ectatomma tuberculatum and species of the genus Camponotus, ants did not protect fruits against seed predators. Furthermore, the result of the interaction was neither related to ant species composition nor to the availability of resources. We suggest that these results may be related to the nature and behavior of the most important seed predators, like Hemicolpus abdominalis weevil which the exoskeleton toughness prevent it from being predated by most ant species. On the other hand, not explored factors, such as reward quality, local ant abundance, ant colony characteristics and/or the presence of alternative energetic sources could also account for variations in ant frequency, composition, and finally ant protective effects, highlighting the conditionality of facultative plant-ant mutualisms.