Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Ecol Evol ; 12(8): e9184, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35949536

RESUMO

In migratory systems, variation in individual phenology can arise through differences in individual migratory behaviors, and this may be particularly apparent in partial migrant systems, where migrant and resident individuals are present within the same population. Links between breeding phenology and migratory behavior or success are generally investigated at the individual level. However, for breeding phenology in particular, the migratory behaviors of each member of the pair may need to be considered simultaneously, as breeding phenology will likely be constrained by timing of the pair member that arrives last, and carryover effects on breeding success may vary depending on whether pair members share the same migratory behavior or not. We used tracking of marked individuals and monitoring of breeding success from a partially migrant population of Eurasian oystercatchers (Haematopus ostralegus) breeding in Iceland to test whether (a) breeding phenology varied with pair migratory behavior; (b) within-pair consistency in timing of laying differed among pair migratory behaviors; and (c) reproductive performance varied with pair migratory behavior, timing of laying, and year. We found that annual variation in timing of laying differed among pair migratory behaviors, with resident pairs being more consistent than migrant and mixed pairs, and migrant/mixed pairs breeding earlier than residents in most years but later in one (unusually cold) year. Pairs that laid early were more likely to replace their clutch after nest loss, had higher productivity and higher fledging success, independent of pair migratory behavior. Our study suggests that the links between individual migratory behavior and reproductive success can vary over time and, to a much lesser extent, with mate migratory behavior and can be mediated by differences in laying dates. Understanding these cascading effects of pair phenology on breeding success is likely to be key to predicting the impact of changing environmental conditions on migratory species.

2.
Forensic Sci Int ; 325: 110879, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34174769

RESUMO

Tsantsas are shrunken human heads originally made for ceremonial purposes by Amazonian indigenous groups of the Shuar and Achuar family, previously called Jivaroan tribes. A significant demand of these objects during the first half of the 20th century led to the manufacture of counterfeit shrunken heads for commercial purposes. For museums where these collections are held, as well as for the indigenous groups who claim their ownership, it is important to identify the origin and authenticity of these tsantsas. We hypothesized that a collection of 14 tsantsas from 3 different museum collections in Ecuador are human and aimed to characterize their sex and potential origin. We amplified the amelogenin gene and performed a high resolution melting analysis to determine their human origin and characterize their sex. We also analyzed a fragment (16209-16402) from the HVR-1 region to identify the mtDNA haplogroups present in the tsantsa collection. Our exploratory results show that all the tsantsas are human and that the collection is comprised of 13 males and 1 female. A total of seven mtDNA haplogroups were found among the tsantsa collection using the mtDNA EMPOP database. These results show a predominance of the Amerindian mtDNA haplogroups B, C and D. Additional principal component analysis, genetic distance tree and haplotype network analyses suggest a relationship between the tsantsa specimens and Native American groups.


Assuntos
Amelogenina/genética , DNA Mitocondrial/genética , Análise para Determinação do Sexo , Crânio , Antropologia Cultural/história , Equador , Etnicidade/genética , Feminino , Genética Forense , Haplótipos , História do Século XIX , História do Século XX , Humanos , Masculino , Museus
3.
Int Ophthalmol ; 41(11): 3587-3592, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34176010

RESUMO

PURPOSE: To analyze high and low contrast visual acuity and contrast sensitivity in diabetic patients without clinically significant macular edema associated or not with non-proliferative diabetic retinopathy. METHODS: Cross-sectional study of 368 eyes of 368 patients classified into three groups: a) disease-free patients, b) patients with diabetes mellitus (DM) without diabetic retinopathy, c) DM patients with non-proliferative diabetic retinopathy. All patients underwent a complete ophthalmological examination that included high and low contrast visual acuity with 1.25%, 2.5% and 5% contrast chart and Pelli-Robson type contrast sensitivity test. RESULTS: We observed no statistically significant differences regarding age, intraocular pressure, duration of diabetes or high contrast visual acuity. The eyes of patients with non-proliferative diabetic retinopathy had worse contrast sensitivity (p = 0.03, in both cases) and low contrast visual acuity at 1.5% (p = 0.03 and p = 0.01), 2.5% (p = 0.01, in both cases) and 5% (p = 0.02 and p = 0.04) than patients free of disease or without diabetic retinopathy. CONCLUSIONS: Analysis of contrast sensitivity and low contrast visual acuity could be considered as markers of visual function impairment in the eyes of patients with non-proliferative diabetic retinopathy.


Assuntos
Diabetes Mellitus , Retinopatia Diabética , Edema Macular , Sensibilidades de Contraste , Estudos Transversais , Retinopatia Diabética/complicações , Retinopatia Diabética/diagnóstico , Humanos , Acuidade Visual
4.
J Clin Med ; 9(9)2020 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-32878150

RESUMO

Graves' orbitopathy (GO) is the most common extrathyroidal manifestation of Graves' disease (GD). Our aim was to assess the efficacy and safety of Tocilizumab (TCZ) in GO refractory to conventional therapy. This was an open-label multicenter study of glucocorticoid-resistant GO treated with TCZ. The main outcomes were the best-corrected visual acuity (BVCA), Clinical Activity Score (CAS) and intraocular pressure (IOP). These outcome variables were assessed at baseline, 1st, 3rd, 6th and 12th month after TCZ therapy onset. The severity of GO was assessed according to the European Group on Graves' Orbitopathy (EUGOGO). We studied 48 (38 women and 10 men) patients (95 eyes); mean age ± standard deviation 51 ± 11.8 years. Before TCZ and besides oral glucocorticoids, they had received IV methylprednisolone (n = 43), or selenium (n = 11). GO disease was moderate (n =29) or severe (n = 19) and dysthyroid optic neuropathy (DON) (n = 7). TCZ was used in monotherapy (n = 45) or combined (n = 3) at a dose of 8 mg/kg IV every four weeks (n = 43) or 162 mg/s.c. every week (n = 5). TCZ yielded a significant improvement in all of the main outcomes at the 1st month that was maintained at one year. Comparing the baseline with data at 1 year all of the variables improved; BCVA (0.78 ± 0.25 vs. 0.9 ± 0.16; p = 0.0001), CAS (4.64 ± 1.5 vs. 1.05 ± 1.27; p = 0.0001) and intraocular pressure (IOP) (19.05 ± 4.1 vs. 16.73 ± 3.4 mmHg; p = 0.007). After a mean follow-up of 16.1 ± 2.1 months, low disease activity (CAS ≤ 3), was achieved in 88 eyes (92.6%) and TCZ was withdrawn in 29 cases due to low disease activity (n = 25) or inefficacy (n = 4). No serious adverse events were observed. In conclusion, TCZ is a useful and safe therapeutic option in refractory GO treatment.

5.
PeerJ ; 8: e9597, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32944417

RESUMO

Capuli (Prunus serotina subsp. capuli) is a tree species that is widely distributed in the northern Andes. In Prunus, fruit set and productivity appears to be limited by gametophytic self-incompatibility (GSI) which is controlled by the S-Locus. For the first time, this research reveals the molecular structure of the capuli S-RNase (a proxy for S-Locus diversity) and documents how S-Locus diversity influences GSI in the species. To this end, the capuli S-RNase gene was amplified and sequenced in order to design a CAPS (Cleaved Amplified Polymorphic Sequence) marker system that could unequivocally detect S-alleles by targeting the highly polymorphic C2-C3 S-RNase intra-genic region. The devised system proved highly effective. When used to assess S-Locus diversity in 15 P. serotina accessions, it could identify 18 S-alleles; 7 more than when using standard methodologies for the identification of S-alleles in Prunus species. CAPS marker information was subsequently used to formulate experimental crosses between compatible and incompatible individuals (as defined by their S-allelic identity). Crosses between heterozygote individuals with contrasting S-alleles resulted in normal pollen tube formation and growth. In crosses between individuals with exactly similar S-allele identities, pollen tubes often showed morphological alterations and arrested development, but for some (suspected) incompatible crosses, pollen tubes could reach the ovary. The latter indicates the possibility of a genotype-specific breakdown of GSI in the species. Overall, this supports the notion that S-Locus diversity influences the reproductive patterns of Andean capuli and that it should be considered in the design of orchards and the production of basic propagation materials.

6.
Ecol Evol ; 8(9): 4409-4421, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29760883

RESUMO

Functional diversity metrics are increasingly used to augment or replace taxonomic diversity metrics to deliver more mechanistic insights into community structure and function. Metrics used to describe landscape structure and characteristics share many of the same limitations as taxonomy-based metrics, particularly their reliance on anthropogenically defined typologies with little consideration of structure, management, or function. However, the development of alternative metrics to describe landscape characteristics has been limited. Here, we extend the functional diversity framework to characterize landscapes based on the diversity of resources available across habitats present. We then examine the influence of resource diversity and provenance on the functional diversities of native and exotic avian communities in New Zealand. Invasive species are increasingly prevalent and considered a global threat to ecosystem function, but the characteristics of and interactions between sympatric native and exotic communities remain unresolved. Understanding their comparative responses to environmental change and the mechanisms underpinning them is of growing importance in predicting community dynamics and changing ecosystem function. We use (i) matrices of resource use (species) and resource availability (habitats) and (ii) occurrence data for 62 native and 25 exotic species and 19 native and 13 exotic habitats in 2015 10 × 10 km quadrats to examine the relationship between native and exotic avian and landscape functional diversity. The numbers of species in, and functional diversities of, native and exotic communities were positively related. Each community displayed evidence of environmental filtering, but it was significantly stronger for exotic species. Less environmental filtering occurred in landscapes providing a more diverse combination of resources, with resource provenance also an influential factor. Landscape functional diversity explained a greater proportion of variance in native and exotic community characteristics than the number of habitat types present. Resource diversity and provenance should be explicitly accounted for when characterizing landscape structure and change as they offer additional mechanistic understanding of the links between environmental filtering and community structure. Manipulating resource diversity through the design and implementation of management actions could prove a powerful tool for the delivery of conservation objectives, be they to protect native species, control exotic species, or maintain ecosystem service provision.

8.
Sci Rep ; 6: 38154, 2016 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-27901077

RESUMO

Landbirds undertaking within-continent migrations have the possibility to stop en route, but most long-distance migrants must also undertake large non-stop sea crossings, the length of which can vary greatly. For shorebirds migrating from Iceland to West Africa, the shortest route would involve one of the longest continuous sea crossings while alternative, mostly overland, routes are available. Using geolocators to track the migration of Icelandic whimbrels (Numenius phaeopus), we show that they can complete a round-trip of 11,000 km making two non-stop sea crossings and flying at speeds of up to 24 m s(−1); one of the fastest recorded for shorebirds flying over the ocean. Although wind support could reduce flight energetic costs, whimbrels faced headwinds up to twice their ground speed, indicating that unfavourable and potentially fatal weather conditions are not uncommon. Such apparently high risk migrations might be more common than previously thought, with potential fitness gains outweighing the costs.


Assuntos
Migração Animal/fisiologia , Charadriiformes/fisiologia , Voo Animal/fisiologia , Vento , África Ocidental , Animais , Feminino , Sistemas de Informação Geográfica , Geografia , Islândia , Masculino , Oceanos e Mares , Fatores de Risco , Tempo (Meteorologia)
9.
Ecol Evol ; 5(12): 2386-96, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26120428

RESUMO

Across the globe, deserts and volcanic eruptions produce large volumes of atmospheric dust, and the amount of dust is predicted to increase with global warming. The effects of long-distance airborne dust inputs on ecosystem productivity are potentially far-reaching but have primarily been measured in soil and plants. Airborne dust could also drive distribution and abundance at higher trophic levels, but opportunities to explore these relationships are rare. Here we use Iceland's steep dust deposition gradients to assess the influence of dust on the distribution and abundance of internationally important ground-nesting bird populations. Surveys of the abundance of breeding birds at 729 locations throughout lowland Iceland were used to explore the influence of dust deposition on bird abundance in agricultural, dry, and wet habitats. Dust deposition had a strong positive effect on bird abundance across Iceland in dry and wet habitats, but not in agricultural land where nutrient levels are managed. The abundance of breeding waders, the dominant group of terrestrial birds in Iceland, tripled on average between the lowest and highest dust deposition classes in both wet and dry habitats. The deposition and redistribution of volcanic materials can have powerful impacts in terrestrial ecosystems and can be a major driver of the abundance of higher trophic-level organisms at broad spatial scales. The impacts of volcanic ash deposition during eruptions and subsequent redistribution of unstable volcanic materials are strong enough to override effects of underlying variation in organic matter and clay content on ecosystem fertility. Global rates of atmospheric dust deposition are likely to increase with increasing desertification and glacier retreat, and this study demonstrates that the effects on ecosystems are likely to be far-reaching, both in terms of spatial scales and ecosystem components.

11.
Buenos Aires; IUCS - Fundacion H. A. Barcelo; 2000. s. n. p. cuadros, graf, ilus, tablas. (63151).
Monografia em Espanhol | BINACIS | ID: bin-63151

Assuntos
Obstetrícia
12.
Buenos Aires; IUCS - Fundacion H. A. Barcelo; 2000. s. n. p. ilus.
Monografia em Espanhol | BINACIS | ID: biblio-1190853

Assuntos
Obstetrícia
13.
Buenos Aires; IUCS - Fundacion H. A. Barcelo; 1997. 33 p. imag, ilus, tablas, cuadros. (63542).
Monografia em Espanhol | BINACIS | ID: bin-63542
14.
Buenos Aires; IUCS - Fundacion H. A. Barcelo; 1997. 33 p. ilus.
Monografia em Espanhol | BINACIS | ID: biblio-1191197
15.
Buenos Aires; IUCS - Fundacion H. A. Barcelo; [2001]. s.p ilus, ecog, cuadros, graf. (63670).
Monografia em Espanhol | BINACIS | ID: bin-63670
16.
Buenos Aires; Instituto Universitario de Cienicas de la Salud - Fund. H. A. Barcelo; 1998. 11 p. fotog. (62897).
Monografia em Espanhol | BINACIS | ID: bin-62897
17.
Buenos Aires; Instituto Universitario de Cienicas de la Salud - Fund. H. A. Barcelo; 1998. 11 p. ^efotog.
Monografia em Espanhol | BINACIS | ID: biblio-1190607
18.
Buenos Aires; IUCS - Fundacion H. A. Barcelo; [2001]. s.p ilus.
Monografia em Espanhol | BINACIS | ID: biblio-1191324
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...