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2.
Curr Biol ; 33(12): 2541-2547.e5, 2023 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-37263270

RESUMO

Diatoms, dinoflagellates, and coccolithophores are dominant groups of marine eukaryotic phytoplankton that are collectively responsible for the majority of primary production in the ocean.1 These phytoplankton contain additional intracellular membranes around their chloroplasts, which are derived from ancestral engulfment of red microalgae by unicellular heterotrophic eukaryotes that led to secondary and tertiary endosymbiosis.2 However, the selectable evolutionary advantage of these membranes and the physiological significance for extant phytoplankton remain poorly understood. Since intracellular digestive vacuoles are ubiquitously acidified by V-type H+-ATPase (VHA),3 proton pumps were proposed to acidify the microenvironment around secondary chloroplasts to promote the dehydration of dissolved inorganic carbon (DIC) into CO2, thus enhancing photosynthesis.4,5 We report that VHA is localized around the chloroplasts of centric diatoms and that VHA significantly contributes to their photosynthesis across a wide range of oceanic irradiances. Similar results in a pennate diatom, dinoflagellate, and coccolithophore, but not green or red microalgae, imply the co-option of phagocytic VHA activity into a carbon-concentrating mechanism (CCM) is common to secondary endosymbiotic phytoplankton. Furthermore, analogous mechanisms in extant photosymbiotic marine invertebrates6,7,8 provide functional evidence for an adaptive advantage throughout the transition from endosymbiosis to symbiogenesis. Based on the contribution of diatoms to ocean biogeochemical cycles, VHA-mediated enhancement of photosynthesis contributes at least 3.5 Gtons of fixed carbon per year (or 7% of primary production in the ocean), providing an example of a symbiosis-derived evolutionary innovation with global environmental implications.


Assuntos
Evolução Biológica , Fitoplâncton , ATPases Vacuolares Próton-Translocadoras , ATPases Vacuolares Próton-Translocadoras/metabolismo , Fitoplâncton/citologia , Fitoplâncton/enzimologia , Fotossíntese , Simbiose , Cloroplastos/metabolismo , Oxigênio/metabolismo , Microalgas/metabolismo
3.
Front Microbiol ; 13: 862812, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35592001

RESUMO

The activity of marine microorganisms depends on community composition, yet, in some oceans, less is known about the environmental and ecological processes that structure their distribution. The objective of this study was to test the effect of geographical distance and environmental parameters on prokaryotic community structure in the Southern Ocean (SO). We described the total (16S rRNA gene) and the active fraction (16S rRNA-based) of surface microbial communities over a ~6,500 km longitudinal transect in the SO. We found that the community composition of the total fraction was different from the active fraction across the zones investigated. In addition, higher α-diversity and stronger species turnover were displayed in the active community compared to the total community. Oceanospirillales, Alteromonadales, Rhodobacterales, and Flavobacteriales dominated the composition of the bacterioplankton communities; however, there were marked differences at the order level. Temperature, salinity, silicic acid, particulate organic nitrogen, and particulate organic carbon correlated with the composition of bacterioplankton communities. A strong distance-decay pattern between closer and distant communities was observed. We hypothesize that it was related to the different oceanic fronts present in the Antarctic Circumpolar Current. Our findings contribute to a better understanding of the complex arrangement that shapes the structure of bacterioplankton communities in the SO.

4.
Eur J Breast Health ; 18(2): 182-189, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35445174

RESUMO

Objective: The aim of this study was to evaluate the existing survival rate and clinical-pathological differences among patients with breast cancer detected by mammographic screening. Materials and Methods: This multicenter cohort study examined 1,248 patients who took part in a national screening program for the early detection of breast cancer over an eight-year period. Results: Of the two patient subgroups (interval and screening), we found significant differences in the distribution of prognostic factors, with interval cases presenting at a lower mean age (p = 0.002), with higher percentages of human epidermal growth factor receptor 2 (HER-2) or triple negative and lower percentages of luminal A or luminal B carcinomas (p = 0.001), advanced stages (p<0.001), lower hormone receptor expression (p<0.001), poorer differentiation (p<0.001) and lower survival (p<0.001). Among the screening group, patients with tumors detected during the first screening round had a significantly lower mean age (p<0.001), a lower frequency of comorbidities (p = 0.038) and a lower tendency (p<0.1) to be diagnosed as triple negative breast carcinomas than incident cases. Conclusion: Our results highlight that breast tumors detected during the first screening round are frequently characterized by a more benign phenotype than the rest of the screening subgroups, which could be of help when stratifying the risk of death and selecting the best treatment option for each patient.

5.
mBio ; 12(6): e0297321, 2021 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-34903046

RESUMO

The Andvord fjord in the West Antarctic Peninsula (WAP) is known for its productivity and abundant megafauna. Nevertheless, seasonal patterns of the molecular diversity and abundance of protistan community members underpinning WAP productivity remain poorly resolved. We performed spring and fall expeditions pursuing protistan diversity, abundance of photosynthetic taxa, and the connection to changing conditions. 18S rRNA amplicon sequence variant (ASV) profiles revealed diverse predatory protists spanning multiple eukaryotic supergroups, alongside enigmatic heterotrophs like the Picozoa. Among photosynthetic protists, cryptophyte contributions were notable. Analysis of plastid-derived 16S rRNA ASVs supported 18S ASV results, including a dichotomy between cryptophytes and diatom contributions previously reported in other Antarctic regions. We demonstrate that stramenopile and cryptophyte community structures have distinct attributes. Photosynthetic stramenopiles exhibit high diversity, with the polar diatom Fragilariopsis cylindrus, unidentified Chaetoceros species, and others being prominent. Conversely, ASV analyses followed by environmental full-length rRNA gene sequencing, electron microscopy, and flow cytometry revealed that a novel alga dominates the cryptophytes. Phylogenetic analyses established that TPG clade VII, as named here, is evolutionarily distinct from cultivated cryptophyte lineages. Additionally, cryptophyte cell abundance correlated with increased water temperature. Analyses of global data sets showed that clade VII dominates cryptophyte ASVs at Southern Ocean sites and appears to be endemic, whereas in the Arctic and elsewhere, Teleaulax amphioxeia and Plagioselmis prolonga dominate, although both were undetected in Antarctic waters. Collectively, our studies provide baseline data against which future change can be assessed, identify different diversification patterns between stramenopiles and cryptophytes, and highlight an evolutionarily distinct cryptophyte clade that thrives under conditions enhanced by warming. IMPORTANCE The climate-sensitive waters of the West Antarctic Peninsula (WAP), including its many fjords, are hot spots of productivity that support multiple marine mammal species. Here, we profiled protistan molecular diversity in a WAP fjord known for high productivity and found distinct spatiotemporal patterns across protistan groups. Alongside first insights to seasonal changes in community structure, we discovered a novel phytoplankton species with proliferation patterns linked to temperature shifts. We then examined evolutionary relationships between this novel lineage and other algae and their patterns in global ocean survey data. This established that Arctic and Antarctic cryptophyte communities have different species composition, with the newly identified lineage being endemic to Antarctic waters. Our research provides critical knowledge on how specific phytoplankton at the base of Antarctic food webs respond to warming, as well as information on overall diversity and community structure in this changing polar environment.


Assuntos
Biodiversidade , Fitoplâncton/isolamento & purificação , Regiões Antárticas , Criptófitas/classificação , Criptófitas/genética , Criptófitas/isolamento & purificação , Estuários , Filogenia , Fitoplâncton/classificação , Fitoplâncton/genética , Plastídeos/classificação , Plastídeos/genética , Estações do Ano , Estramenópilas/classificação , Estramenópilas/genética , Estramenópilas/isolamento & purificação
6.
Cancer Med ; 8(15): 6662-6670, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31549794

RESUMO

The aim of this study is to determine the survival of patients with breast cancer treated with adjuvant chemotherapy (ACh) after the diagnosis by screening, taking comorbidity into account. This multicenter cohort study examined a population of patients taking part in four national screening programs for the early detection of breast cancer (localized or locally advanced), during the period 2000-2008. Of the 1248 cancers detected, 266 were prevalent (21.3%), 633 were incident (50.7%), and 349 were interval (27.9%). No significant differences were detected between the three groups in terms of the distribution of comorbidity according to the CCI. After a median follow-up of 102 months, 22.1% of the patients with interval cancer had died. The corresponding figures for the incident and prevalent cancers were 10.4% and 7.9%, respectively (P < .001). The adjusted Cox regression analysis by the stage, CCI and group revealed no differences in the risk of recurrence between the different groups according to the ACh performed. However, there were significant differences in the overall survival; for the interval cancer group without ACh, the risk of death was higher (Hazard ratio: 2.5 [1.0-6.2]) than for the other two groups. However, for the prevalent and incident groups that did not receive ACh, there was no greater risk of death. This study shows that adjuvant chemotherapy seems to benefit patients with interval breast cancer, who have a poorer prognosis than those with prevalent or incident cancer. However, the role of ACh is unclear with respect to prevalent and incident cancers when comorbidity is taken into account.


Assuntos
Neoplasias da Mama/diagnóstico , Neoplasias da Mama/tratamento farmacológico , Quimioterapia Adjuvante/métodos , Idoso , Neoplasias da Mama/mortalidade , Detecção Precoce de Câncer , Feminino , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Análise de Regressão , Estudos Retrospectivos , Análise de Sobrevida , Resultado do Tratamento
7.
PLoS One ; 14(2): e0211107, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30726270

RESUMO

As the Western Antarctic Peninsula (WAP) region responds to a warmer climate, the impacts of glacial meltwater on the Southern Ocean are expected to intensify. The Antarctic Peninsula fjord system offers an ideal system to understand meltwater's properties, providing an extreme in the meltwater's spatial gradient from the glacio-marine boundary to the WAP continental shelf. Glacial meltwater discharge in Arctic and Greenland fjords is typically characterized as relatively lower temperature, fresh and with high turbidity. During two cruises conducted in December 2015 and April 2016 in Andvord Bay, we found a water lens of low salinity and low temperature along the glacio-marine interface. Oxygen isotope ratios identified this water lens as a mixture of glacial ice and deep water in Gerlache Strait suggesting this is glacial meltwater. Conventional hydrographic measurements were combined with optical properties to effectively quantify its spatial extent. Fine suspended sediments associated with meltwater (nanoparticles of ~ 5nm) had a significant impact on the underwater light field and enabled the detection of meltwater characteristics and spatial distribution. In this study, we illustrate that glacial meltwater in Andvord Bay alters the inherent and apparent optical properties of the water column, and develop statistical models to predict the meltwater content from hydrographic and optical measurements. The predicted meltwater fraction is in good agreement with in-situ values. These models offer a potential for remote sensing and high-resolution detection of glacial meltwater in Antarctic waters. Furthermore, the possible influence of meltwater on phytoplankton abundance in the surface is highlighted; a significant correlation is found between meltwater fraction and chlorophyll concentration.


Assuntos
Clorofila/metabolismo , Fitoplâncton/fisiologia , Regiões Antárticas , Ecossistema , Estuários , Camada de Gelo , Fenômenos Ópticos , Isótopos de Oxigênio/metabolismo , Água
8.
Rev. senol. patol. mamar. (Ed. impr.) ; 29(2): 86-89, abr.-jun. 2016. ilus
Artigo em Espanhol | IBECS | ID: ibc-153248

RESUMO

Las metástasis ganglionares axilares contralaterales son un fenómeno poco frecuente en el cáncer de mama. Aunque se considera un estadio iv de la enfermedad, hay hipótesis que postulan que la diseminación de las células tumorales hasta los ganglios axilares contralaterales podría producirse mediante vía linfática y no por vía hematógena. Presentamos el caso de una paciente de 35 años, diagnosticada de carcinoma ductal infiltrante de mama en estadio iii y tratada con quimioterapia neoadyuvante, mastectomía radical modificada, radioterapia y hormonoterapia. Siete meses después del tratamiento quirúrgico la enfermedad progresó con metástasis axilares contralaterales, sin evidencia de otra afectación a distancia. Se trata de una evolución inusual del cáncer de mama, y por tanto su manejo no está estandarizado. Hemos realizado una revisión de la literatura para buscar la mejor opción terapéutica en pacientes que presentan esta situación clínica (AU)


Contralateral axillary lymph node metastases are a rare presentation in breast cancer. Although they are considered stage IV of the disease, it has been postulated that the spread of tumour cells to the contralateral axillary lymph nodes could occur through the lymph vessels and not through the bloodstream. We report the case of a 35-year-old woman who was diagnosed with a stage III invasive breast carcinoma and was treated with neoadjuvant chemotherapy, modified radical mastectomy, radiotherapy and hormone therapy. Seven months after the surgery, the disease progressed, showing contralateral axillary lymph node metastases with no evidence of any other distant disease. This is an unusual progression of breast cancer and thus its management is not standardized. We reviewed the literature to search for evidence on how to treat this very special clinical situation (AU)


Assuntos
Humanos , Feminino , Adulto , Neoplasias da Mama/complicações , Prognóstico , Metástase Linfática/patologia , Metástase Linfática , Metástase Neoplásica/patologia , Mamografia/instrumentação , Mamografia/métodos , Mastectomia Radical Modificada/métodos , Terapia Neoadjuvante/métodos , Terapia Neoadjuvante , Axila/patologia , Axila , Mastectomia Radical Modificada , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/terapia , Carcinoma Ductal de Mama/complicações , Carcinoma Ductal de Mama/patologia , Mamografia , Excisão de Linfonodo/métodos , Seguimentos
9.
New Phytol ; 210(3): 890-904, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26844818

RESUMO

Diatoms are one of the most productive and successful photosynthetic taxa on Earth and possess attributes such as rapid growth rates and production of lipids, making them candidate sources of renewable fuels. Despite their significance, few details of the mechanisms used to regulate growth and carbon metabolism are currently known, hindering metabolic engineering approaches to enhance productivity. To characterize the transcript level component of metabolic regulation, genome-wide changes in transcript abundance were documented in the model diatom Thalassiosira pseudonana on a time-course of silicon starvation. Growth, cell cycle progression, chloroplast replication, fatty acid composition, pigmentation, and photosynthetic parameters were characterized alongside lipid accumulation. Extensive coordination of large suites of genes was observed, highlighting the existence of clusters of coregulated genes as a key feature of global gene regulation in T. pseudonana. The identity of key enzymes for carbon metabolic pathway inputs (photosynthesis) and outputs (growth and storage) reveals these clusters are organized to synchronize these processes. Coordinated transcript level responses to silicon starvation are probably driven by signals linked to cell cycle progression and shifts in photophysiology. A mechanistic understanding of how this is accomplished will aid efforts to engineer metabolism for development of algal-derived biofuels.


Assuntos
Carbono/metabolismo , Diatomáceas/genética , Diatomáceas/metabolismo , Metabolismo dos Lipídeos/genética , Silício/deficiência , Ciclo Celular/efeitos da radiação , Diatomáceas/efeitos da radiação , Metabolismo Energético/genética , Metabolismo Energético/efeitos da radiação , Citometria de Fluxo , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Genes de Plantas , Genoma de Planta , Luz , Metabolismo dos Lipídeos/efeitos da radiação , Modelos Biológicos , Anotação de Sequência Molecular , Família Multigênica , Pigmentação/genética , Pigmentação/efeitos da radiação , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Estresse Fisiológico/genética , Estresse Fisiológico/efeitos da radiação
10.
Psychiatry Res ; 233(3): 331-8, 2015 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-26145769

RESUMO

Obesity is associated with structural and functional alterations in brain areas that are often functionally distinct and anatomically distant. This suggests that obesity is associated with differences in functional connectivity of regions distributed across the brain. However, studies addressing whole brain functional connectivity in obesity remain scarce. Here, we compared voxel-wise degree centrality and eigenvector centrality between participants with obesity (n=20) and normal-weight controls (n=21). We analyzed resting state and task-related fMRI data acquired from the same individuals. Relative to normal-weight controls, participants with obesity exhibited reduced degree centrality in the right middle frontal gyrus in the resting-state condition. During the task fMRI condition, obese participants exhibited less degree centrality in the left middle frontal gyrus and the lateral occipital cortex along with reduced eigenvector centrality in the lateral occipital cortex and occipital pole. Our results highlight the central role of the middle frontal gyrus in the pathophysiology of obesity, a structure involved in several brain circuits signaling attention, executive functions and motor functions. Additionally, our analysis suggests the existence of task-dependent reduced centrality in occipital areas; regions with a role in perceptual processes and that are profoundly modulated by attention.


Assuntos
Lobo Frontal/metabolismo , Imageamento por Ressonância Magnética/métodos , Obesidade/metabolismo , Lobo Occipital/metabolismo , Desempenho Psicomotor/fisiologia , Descanso/fisiologia , Adulto , Atenção/fisiologia , Mapeamento Encefálico/métodos , Feminino , Humanos , Masculino , Rede Nervosa/metabolismo , Obesidade/diagnóstico , Adulto Jovem
11.
Am J Med Genet B Neuropsychiatr Genet ; 165B(3): 245-53, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24619555

RESUMO

The prevalence of obesity is increasing worldwide. Previous research has shown a relationship between obesity and both executive functioning alterations and frontal cortex volume reductions. The Brain Derived Neurotrophic Factor val66met polymorphism, involved in eating behavior, has also been associated with executive functions and prefrontal cortex volume, but to date it has not been studied in relation to obesity. Our aim is to elucidate whether the interaction between the Brain Derived Neurotrophic Factor val66met polymorphism and obesity status influences executive performance and frontal-subcortical brain structure. Sixty-one volunteers, 34 obese and 27 controls, age range 12-40, participated in the study. Participants were assigned to one of two genotype groups (met allele carriers, n = 16, or non-carriers, n = 45). Neuropsychological assessment comprised the Trail Making Test, the Stroop Test and the Wisconsin Card Sorting Test, all tasks that require response inhibition and cognitive flexibility. Subjects underwent magnetic resonance imaging in a Siemens TIM TRIO 3T scanner and images were analyzed using the FreeSurfer software. Analyses of covariance controlling for age and intelligence showed an effect of the obesity-by-genotype interaction on perseverative responses on the Wisconsin Card Sorting Test as well as on precentral and caudal middle frontal cortical thickness: obese met allele carriers showed more perseverations on the Wisconsin Card Sorting Test and lower frontal thickness than obese non-carriers and controls. In conclusion, the Brain Derived Neurotrophic Factor may play an important role in executive functioning and frontal brain structure in obesity.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/genética , Função Executiva/fisiologia , Obesidade/genética , Polimorfismo Genético , Córtex Pré-Frontal/patologia , Adolescente , Adulto , Alelos , Criança , Cognição/fisiologia , Feminino , Genótipo , Humanos , Masculino , Testes Neuropsicológicos , Polimorfismo Genético/genética , Adulto Jovem
12.
Psychiatry Res ; 214(2): 109-15, 2013 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-24041490

RESUMO

Obesity depends on homeostatic and hedonic food intake behavior, mediated by brain plasticity changes in cortical and subcortical structures. The aim of this study was to investigate cortical thickness and subcortical volumes of regions related to food intake behavior in a healthy young adult sample with obesity. Thirty-seven volunteers, 19 with obesity (age=33.7±5.7 (20-39) years body-mass index (BMI)=36.08±5.92 (30.10-49.69)kg/m(2)) and 18 controls (age=32.3±5.9 (21-40) years; BMI=22.54±1.94 (19.53-24.97)kg/m(2)) participated in the study. Patients with neuropsychiatric or biomedical disorders were excluded. We used FreeSurfer software to analyze structural magnetic resonance images (MRI) and obtain global brain measures, cortical thickness and subcortical volume estimations. Finally, correlation analyses were performed for brain structure data and obesity measures. There were no between-group differences in age, gender, intelligence or education. Results showed cortical thickness reductions in obesity in the left superior frontal and right medial orbitofrontal cortex. In addition, the obesity group had lower ventral diencephalon and brainstem volumes than controls, while there were no differences in any other subcortical structure. There were no statistically significant correlations between brain structure and obesity measures. Overall, our work provides evidence of the structural brain characteristics associated with metabolically normal obesity. We found reductions in cortical thickness, ventral diencephalon and brainstem volumes in areas that have been implicated in food intake behavior.


Assuntos
Córtex Cerebral/patologia , Obesidade/patologia , Adulto , Análise de Variância , Índice de Massa Corporal , Mapeamento Encefálico , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem
13.
Hum Brain Mapp ; 34(11): 2786-97, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22522963

RESUMO

Obesity is a major health problem in modern societies. It has been related to abnormal functional organization of brain networks believed to process homeostatic (internal) and/or salience (external) information. This study used resting-state functional magnetic resonance imaging analysis to delineate possible functional changes in brain networks related to obesity. A group of 18 healthy adult participants with obesity were compared with a group of 16 lean participants while performing a resting-state task, with the data being evaluated by independent component analysis. Participants also completed a neuropsychological assessment. Results showed that the functional connectivity strength of the putamen nucleus in the salience network was increased in the obese group. We speculate that this abnormal activation may contribute to overeating through an imbalance between autonomic processing and reward processing of food stimuli. A correlation was also observed in obesity between activation of the putamen nucleus in the salience network and mental slowness, which is consistent with the notion that basal ganglia circuits modulate rapid processing of information.


Assuntos
Processos Mentais/fisiologia , Rede Nervosa/patologia , Obesidade/patologia , Adolescente , Adulto , Composição Corporal , Índice de Massa Corporal , Mapeamento Encefálico , Cognição/fisiologia , Interpretação Estatística de Dados , Feminino , Homeostase/fisiologia , Humanos , Fome/fisiologia , Processamento de Imagem Assistida por Computador , Sistema Límbico/fisiologia , Imageamento por Ressonância Magnética , Masculino , Memória/fisiologia , Vias Neurais/patologia , Testes Neuropsicológicos , Obesidade/psicologia , Análise de Componente Principal , Desempenho Psicomotor/fisiologia , Putamen/anatomia & histologia , Putamen/fisiologia , Análise de Regressão , Aprendizagem Verbal/fisiologia , Adulto Jovem
15.
PLoS One ; 7(7): e41482, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22848508

RESUMO

Obesity is a multifactorial disease caused by the interaction between genotype and environment, and it is considered to be a type of addictive alteration. The A1 allele of the DRD2/ANKK1-TaqIA gene has been associated with addictive disorders, with obesity and with the performance in executive functions. The 7 repeat allele of the DRD4 gene has likewise been associated with the performance in executive functions, as well as with addictive behaviors and impulsivity. Participants were included in the obesity group (N = 42) if their body mass index (BMI) was equal to or above 30, and in the lean group (N = 42) if their BMI was below 25. The DRD2/ANKK1-TaqIA and DRD4 VNTR polymorphisms were obtained. All subjects underwent neuropsychological assessment. Eating behavior traits were evaluated. The 'DRD2/ANKK1-TaqIA A1-allele status' had a significant effect on almost all the executive variables, but no significant 'DRD4 7R-allele status' effects were observed for any of the executive variables analyzed. There was a significant 'group' x 'DRD2/ANKK1-TaqIA A1-allele status' interaction effect on LN and 'group' x 'DRD4 7R-allele status' interaction effect on TMT B-A score. Being obese and a carrier of the A1 allele of DRD2/ANKK1-TaqIA or the 7R allele of DRD4 VNTR polymorphisms could confer a weakness as regards the performance of executive functions.


Assuntos
Alelos , Tomada de Decisões , Interação Gene-Ambiente , Obesidade/genética , Polimorfismo Genético , Receptores de Dopamina D4/genética , Adulto , Índice de Massa Corporal , Feminino , Humanos , Masculino , Obesidade/fisiopatologia , Receptores de Dopamina D4/metabolismo
17.
J Phycol ; 48(1): 222-30, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27009666

RESUMO

We offer an emended description of the genus Thalassioneis based on new observations of the type species, T. signyensis Round, from material sampled in the northwest Weddell Sea. Specimens from algal communities attached to submerged flanks of several icebergs were collected with a remote-operated vehicle (ROV-Phantom DS 2). The analyses were carried out by LM and SEM. Fresh material and frustules without organic matter allowed us to observe details not included in the original description such as type and structure of colonies and chloroplasts. The frustule shows an asymmetry with respect to the location of the apical pore fields, one of them situated on the valvar face and the other one displaced toward the mantle; the former is involved in joining contiguous cells to form long chains. Furthermore, we present details on the ultrastructure of the cingulum that consists of three to four open copulae with one or more rows of poroids. A brief discussion on the habit and ecology of this taxon, which may be endemic to the northwest Weddell Sea, is also presented. A comparison with similar genera, such as Brandinia, Creania, Fossula, Fragilaria, Rimoneis, Synedropsis, and Ulnaria, is included with an evaluation of morphological characteristics useful to differentiate them.

18.
Photochem Photobiol Sci ; 10(12): 1854-67, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21971566

RESUMO

Ultraviolet radiation (UVR) plays a key role in several biological functions, including human health. Skin exposure to UVR is the main factor in vitamin D photoconversion. There is also evidence relating low levels of vitamin D with certain internal cancers, mainly colon, breast and prostate, as well as other diseases. Several epidemiological studies have shown an inverse relationship between the above-mentioned diseases and latitude, in accordance with the ultraviolet radiation latitudinal gradient. The aim of this study is to determine whether UV irradiance levels in the southern South America are sufficient to produce suitable levels of vitamin D year around. For this purpose, vitamin D photoconversion weighted-irradiance was analyzed between S.S. de Jujuy (24.17°S, 65.02°W) and Ushuaia (54° 50'S, 68° 18'W). In addition to irradiance, skin type and area of body exposed to sunlight are critical factors in vitamin D epidemiology. Due to a broad ethnic variability, it was assumed that the skin type in this region varies between II and V (from the most to the less sensitive). All sites except South Patagonia indicate that skin II under any condition of body area exposure and skin V when exposing head, hands, arms and legs, would produce suitable levels of vitamin D year round (except for some days in winter at North Patagonian sites). At South Patagonian sites, minimum healthy levels of vitamin D year round can be reached only by the more sensitive skin II type, if exposing head, hands, arms and legs, which is not a realistic scenario during winter. At these southern latitudes, healthy vitamin D levels would not be obtained between mid May and beginning of August if exposing only the head. Skin V with head exposure is the most critical situation; with the exception of the tropics, sun exposure would not produce suitable levels of vitamin D around winter, during a time period that varies with latitude. Analyzing the best exposure time during the day in order to obtain a suitable level of vitamin D without risk of sunburn, it was concluded that noon is best during winter, as determined previously. For skin type II when exposing head, exposure period in winter varies between 30 and 130 min, according to latitude, except for South Patagonian sites. During summer, noon seems to be a good time of day for short periods of exposure, while during leisure times, longer periods of exposure without risk of sunburn are possible at mid-morning and mid-afternoon. At 3 h from noon, solar zenith angles are almost the same for sites between the tropics and North Patagonia, and at 4 h from noon, for all sites. Then, in these cases, the necessary exposure periods varied slightly between sites, only due to meteorological differences.


Assuntos
Raios Ultravioleta , Vitamina D/biossíntese , Humanos , Pele/efeitos da radiação , América do Sul , Luz Solar , Fatores de Tempo , Vitamina D/efeitos da radiação
19.
Proc Natl Acad Sci U S A ; 108(14): 5492-7, 2011 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-21444769

RESUMO

We describe the results from a spatial cyberinfrastructure developed to characterize the meltwater field around individual icebergs and integrate the results with regional- and global-scale data. During the course of the cyberinfrastructure development, it became clear that we were also building an integrated sampling planning capability across multidisciplinary teams that provided greater agility in allocating expedition resources resulting in new scientific insights. The cyberinfrastructure-enabled method is a complement to the conventional methods of hydrographic sampling in which the ship provides a static platform on a station-by-station basis. We adapted a sea-floor mapping method to more rapidly characterize the sea surface geophysically and biologically. By jointly analyzing the multisource, continuously sampled biological, chemical, and physical parameters, using Global Positioning System time as the data fusion key, this surface-mapping method enables us to examine the relationship between the meltwater field of the iceberg to the larger-scale marine ecosystem of the Southern Ocean. Through geospatial data fusion, we are able to combine very fine-scale maps of dynamic processes with more synoptic but lower-resolution data from satellite systems. Our results illustrate the importance of spatial cyberinfrastructure in the overall scientific enterprise and identify key interfaces and sources of error that require improved controls for the development of future Earth observing systems as we move into an era of peta- and exascale, data-intensive computing.


Assuntos
Coleta de Dados/métodos , Congelamento , Geografia , Camada de Gelo , Informática/métodos , Disseminação de Informação/métodos , Tecnologia de Sensoriamento Remoto/métodos , Regiões Antárticas , Ecossistema , Sistemas de Informação Geográfica , Informática/tendências , Oceanos e Mares , Salinidade , Temperatura
20.
Aten. prim. (Barc., Ed. impr.) ; 43(1): 41-48, ene. 2011. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-88161

RESUMO

ObjetivoConocer la viabilidad de la realización de la exploración oftalmológica básica de la patología ocular del paciente diabético desde el ámbito de la Atención Primaria de Salud (APS).DiseñoEstudio transversal observacional prospectivo y multicéntrico.Participantes y métodoMuestra de 712 diabéticos tipo II. Intervenciones: realización, por parte de un optometrista, de una exploración de la agudeza visual, medición de la presión intraocular y fotografía de fondo de ojo con cámara de retina no midriática. Interpretación de los resultados e indicación de derivación realizada, a doble ciego, por oftalmólogos y médicos APS.ResultadosAlteración agudeza visual: médico APS 43,7%, oftalmólogo 36,1%, concordancia 70%; sospecha glaucoma: médico APS 8,8%, oftalmólogo 7,6%, concordancia 94%; retinopatía diabética: médico APS 28,2%, oftalmólogo 13,4%, concordancia 78%. Derivación Servicios Oftalmología: médico APS 56,8%, oftalmólogo 41,3% (p=0,001).ConclusionesEl nivel de concordancia en los diagnósticos entre médico APS y oftalmólogo hace fiable la exploración oftalmológica del paciente diabético desde el ámbito de la APS. A pesar del supradiagnóstico y del 16% de derivación no justificada realizada por parte del médico APS, se evita la derivación a las consultas de oftalmología, de cerca de la mitad de los pacientes diabéticos(AU)


ObjectiveTo study the feasibility of a basic ophthalmological examination for the eye disease in diabetic patients by Primary Health Care (PHC).InterventionsVisual acuity examination, intraocular pressure measurement and the eye fundus photograph with a non-mydriatic camera taken by an optometrist. The interpretation and subsequent referral to an ophthalmology department by ophthalmologists and general practitioners (GP).ResultsVisual acuity deficiency: GP, 43.7%; ophthalmologist, 36.1%; concordance, 70%; glaucoma suspicion: GP, 8.8%; ophthalmologist, 7.6%; concordance, 94%; diabetic retinopathy: GP, 28.2%; ophthalmologist, 13.4%; concordance, 78%. Ophthalmology Department referral: GP, 56.8%; ophthalmologist, 41.3% (P=0.001).ConclusionsAgreement between GP and ophthalmologist leads to a reliable ophthalmological examination of the diabetic patient in PHC. Despite an over-diagnosis and 16% of non-justified referrals by the GP, Ophthalmology Department referral is avoided in almost half of the diabetic patients(AU)


Assuntos
Humanos , Oftalmopatias/diagnóstico , Retinopatia Diabética/diagnóstico , Complicações do Diabetes/diagnóstico , Atenção Primária à Saúde/estatística & dados numéricos , Encaminhamento e Consulta/estatística & dados numéricos
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