29 research outputs found
Relative Stability of Core Groups in Pollination Networks in a Biodiversity Hotspot over Four Years
Plants and their pollinators form pollination networks integral to the evolution and persistence of species in communities. Previous studies suggest that pollination network structure remains nested while network composition is highly dynamic. However, little is known about temporal variation in the structure and function of plant-pollinator networks, especially in species-rich communities where the strength of pollinator competition is predicted to be high. Here we quantify temporal variation of pollination networks over four consecutive years in an alpine meadow in the Hengduan Mountains biodiversity hotspot in China. We found that ranked positions and idiosyncratic temperatures of both plants and pollinators were more conservative between consecutive years than in non-consecutive years. Although network compositions exhibited high turnover, generalized core groups – decomposed by a k-core algorithm – were much more stable than peripheral groups. Given the high rate of turnover observed, we suggest that identical plants and pollinators that persist for at least two successive years sustain pollination services at the community level. Our data do not support theoretical predictions of a high proportion of specialized links within species-rich communities. Plants were relatively specialized, exhibiting less variability in pollinator composition at pollinator functional group level than at the species level. Both specialized and generalized plants experienced narrow variation in functional pollinator groups. The dynamic nature of pollination networks in the alpine meadow demonstrates the potential for networks to mitigate the effects of fluctuations in species composition in a high biodiversity area
Seleção para caracteres componentes de aparência e rendimento de tubérculo em plântulas de batata
Frequency and antimicrobial resistance patterns of bacteria implicated in community urinary tract infections: a ten-year surveillance study (2000-2009)
BACKGROUND Urinary tract infection (UTI) is one of the most common infectious diseases at the community level. In order to assess the adequacy of the empirical therapy, the prevalence and the resistance pattern of the main bacteria responsible for UTI in the community (in Aveiro, Portugal) was evaluated throughout a ten-year period. METHODS In this retrospective study, all urine samples from patients of the District of Aveiro, in ambulatory regime, collected at the Clinical Analysis Laboratory Avelab during the period 2000-2009 were analysed. Samples with more than 105 CFU/mL bacteria were considered positive and, for these samples, the bacteria were identified and the profile of antibiotic susceptibility was characterized. RESULTS From the 155597 samples analysed, 18797 (12.1%) were positive for bacterial infection. UTI was more frequent in women (78.5%) and its incidence varied with age, affecting more the elderly patients (38.6%). Although E. coli was, as usual, the most common pathogen implicated in UTI, it were observed differences related to the other bacteria more implicated in UTI relatively to previous studies. The bacteria implicated in the UTI varied with the sex of the patient, being P. aeruginosa a more important cause of infection in men than in women. The incidence of the main bacteria changed over the study period (P. aeruginosa, Klebsiella spp and Providencia spp increased and Enterobacter spp decreased). Although E. coli was responsible for more than an half of UTI, its resistance to antibiotics was low when compared with other pathogens implicated in UTI, showing also the lowest percentage of multidrug resistant (MDR) isolates (17%). Bacteria isolated from females were less resistant than those isolated from males and this difference increased with the patient age. CONCLUSIONS The differences in sex and age must be taken into account at the moment of empirical prescription of antimicrobials. From the recommended antimicrobials by the European Association of Urology guidelines, the first line drugs (pivmecillinam and nitrofurantoin) and the alternative antibiotic amoxicillin-clavulanic acid (AMX-CLA) are appropriate to treat community-acquired UTI, but the fluoroquinolones should not be suitable to treat male infections and the trimethoprim-sulfamethoxazole (SXT) shall not be used in the treatment of UTI at this level.Thanks are due to the University of Aveiro, Centre for Environmental and Marine Studies (CESAM) for funding the Microbiology Research Group (Project Pest-C/MAR/LA0017/2011) and to Clinical Analysis Laboratory Avelab (Portugal) for supplying the data.publishe
A holoparasitic plant severely reduces the vegetative and reproductive performance of its host plant in the Caatinga, a Brazilian seasonally dry forest
Exposure and connectedness to natural environments: An examination of the measurement invariance of the Nature Exposure Scale (NES) and Connectedness to Nature Scale (CNS) across 65 nations, 40 languages, gender identities, and age groups
Detachment from nature is contributing to the environmental crisis and reversing this trend requires detailed monitoring and targeted interventions to reconnect people to nature. Most tools measuring nature exposure and attachment were developed in high-income countries and little is known about their robustness across national and linguistic groups. Therefore, we used data from the Body Image in Nature Survey to assess measurement invariance of the Nature Exposure Scale (NES) and the Connectedness to Nature Scale (CNS) across 65 nations, 40 languages, gender identities, and age groups (N = 56,968). While multi-group confirmatory factor analysis (MG-CFA) of the NES supported full scalar invariance across gender identities and age groups, only partial scalar invariance was supported across national and linguistic groups. MG-CFA of the CNS also supported full scalar invariance across gender identities and age groups, but only partial scalar invariance of a 7-item version of the CNS across national and linguistic groups. Nation-level associations between NES and CNS scores were negligible, likely reflecting a lack of conceptual clarity over what the NES is measuring. Individual-level associations between both measures and sociodemographic variables were weak. Findings suggest that the CNS-7 may be a useful tool to measure nature connectedness globally, but measures other than the NES may be needed to capture nature exposure cross-culturally
Body appreciation around the world: Measurement invariance of the Body Appreciation Scale-2 (BAS-2) across 65 nations, 40 languages, gender identities, and age
The Body Appreciation Scale-2 (BAS-2) is a widely used measure of a core facet of the positive body image construct. However, extant research concerning measurement invariance of the BAS-2 across a large number of nations remains limited. Here, we utilised the Body Image in Nature (BINS) dataset - with data collected between 2020 and 2022 - to assess measurement invariance of the BAS-2 across 65 nations, 40 languages, gender identities, and age groups. Multi-group confirmatory factor analysis indicated that full scalar invariance was upheld across all nations, languages, gender identities, and age groups, suggesting that the unidimensional BAS-2 model has widespread applicability. There were large differences across nations and languages in latent body appreciation, while differences across gender identities and age groups were negligible-to-small. Additionally, greater body appreciation was significantly associated with higher life satisfaction, being single (versus being married or in a committed relationship), and greater rurality (versus urbanicity). Across a subset of nations where nation-level data were available, greater body appreciation was also significantly associated with greater cultural distance from the United States and greater relative income inequality. These findings suggest that the BAS-2 likely captures a near-universal conceptualisation of the body appreciation construct, which should facilitate further cross-cultural research
Clinical Characteristics and Treatment Outcomes of Patients With Advanced Germ Cell Tumor Treated at a Tertiary Cancer Center in Brazil
Geosteranes: Identification and synthesis of a novel series of 3-substituted steranes
A novel series of 3-alkyl and 3-carboxyalkyl-5 beta(H)-steranes 7-10 along with a full homologous series of carboxyalkyl-sterane (C-1 to C-6) 4-6 with 3 alpha(H)5 alpha(H) configuration have been identified in marine-evaporitic oils from Fazenda Belim, Potiguar Basin (Brazil) on the basis of mass spectral interpretation. The synthesis of enantiomerically pure 3 alpha-alkyl-5 beta(H)-cholestane and 3 beta-alkyl-5 alpha(H)-cholestane standards and their coinjection with petroleum fractions confirmed the structural assignments. (C) 1997 Elsevier Science Ltd.264198478779
3-alkyl and 3-carboxyalkyl steranes in marine evaporitic oils of the Potiguar Basin, Brazil
The geochemical characterization of marine evaporitic oils from the Fazenda Belem oil field, Potiguar Basin, Brazil showed good correlation between both acidic and neutral fractions, and led to the identification of several biomarkers including the homologous series of 3-alkyl- and 3-carboxyalkyl-5 alpha(H) steranes and also the new series of 3-alkyl- and 3-carboxyalkyl-5 beta(H) steranes. These compounds were identified using GC/MS and their structures were confirmed by coinjection with synthetic standards. A minor series of 4-carboxyalkyl steranes was also detected. The analysis of the acidic biomarkers allowed a more accurate evaluation of maturation, biodegradation and migration of the studied oils. (C) 1999 Elsevier Science B.V. All rights reserved.1584167112
