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1.
Psychol Med ; 54(6): 1172-1183, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37859623

RESUMO

BACKGROUND: Major depressive disorder (MDD) contributes to suicide risk. Treating MDD effectively is considered a key suicide prevention intervention. Yet many patients with MDD do not respond to their initial medication and require a 'next-step'. The relationship between next-step treatments and suicidal thoughts and behaviors is uncharted. METHOD: The VA Augmentation and Switching Treatments for Depression trial randomized 1522 participants to one of three next-step treatments: Switching to Bupropion, combining with Bupropion, and augmenting with Aripiprazole. In this secondary analysis, features associated with lifetime suicidal ideation (SI) and attempts (SA) at baseline and current SI during treatment were explored. RESULTS: Compared to those with SI only, those with lifetime SI + SA were more likely to be female, divorced, or separated, unemployed; and to have experienced more childhood adversity. They had a more severe depressive episode and were more likely to respond to 'next-step' treatment. The prevalence of SI decreased from 46.5% (694/1492) at baseline to 21.1% (315/1492) at end-of-treatment. SI during treatment was associated with baseline SI; low positive mental health, more anxiety, greater severity and longer duration of current MDD episode; being male and White; and treatment with S-BUP or C-BUP as compared to A-ARI. CONCLUSION: SI declines for most patients during next-step medication treatments. But about 1 in 5 experienced emergent or worsening SI during treatment, so vigilance for suicide risk through the entire 12-week acute treatment period is necessary. Treatment selection may affect the risk of SI.


Assuntos
Transtorno Depressivo Maior , Ideação Suicida , Humanos , Masculino , Feminino , Bupropiona/uso terapêutico , Transtorno Depressivo Maior/epidemiologia , Antidepressivos/uso terapêutico , Aripiprazol/farmacologia , Aripiprazol/uso terapêutico
3.
Autophagy ; 19(7): 2159-2161, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36469687

RESUMO

Autophagosomes are crucial components of the cellular recycling machinery that form at endoplasmic reticulum (ER)-associated sites. As the autophagosome membrane is largely devoid of transmembrane proteins, autophagosome biogenesis is thought to be largely regulated by lipid transfer and lipid modifications, as well as membrane-associated proteins. While the membrane origin of autophagosomes and their lipid composition are still incompletely understood, previous studies have found the autophagosome membrane to be enriched in unsaturated fatty acids and have little cholesterol, suggesting that cholesterol removal is an integral step during autophagosome biogenesis. In our study, we demonstrate that short term cholesterol depletion leads to a rapid induction of autophagy and identify the ER-localized cholesterol transport protein GRAMD1C as a negative regulator of starvation-induced macroautophagy/autophagy. Abbreviations: ATG: autophagy related; ccRCC: clear cell renal cell carcinoma; ER: endoplasmic reticulum; GRAM: glucosyltransferases, RAB-like GTPase activators and myotubularins; GRAMD: GRAM domain containing; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MCBD: methyl-cyclodextrin; MTOR: mechanistic target of rapamycin kinase; VASt: VAD1 analog of StAR-related lipid transfer.


Assuntos
Autofagossomos , Autofagia , Autofagossomos/metabolismo , Autofagia/fisiologia , Proteínas de Transporte/metabolismo , Macroautofagia , Proteínas de Membrana/metabolismo , Colesterol/metabolismo , Lipídeos
4.
Radiol Case Rep ; 18(12): 4479-4484, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37868013

RESUMO

Physicians are facing a growing challenge in characterizing suspicious pulmonary lesions through biopsy. Video thoracoscopic surgery is crucial for conducting surgical biopsies of these nodules. However, accurately identifying small pulmonary nodules, tiny, subsolid, and deep ones, remains a significant challenge due to the absence of digital palpation. One proposed technique for localization involves using a harpoon, initially designed for mammary nodules but also applied to pulmonary nodules. In cases involving solitary pulmonary nodules, histologic characterization is often necessary also accurate descriptions through computed tomography and the patient's clinical and epidemiologic context allow for a presumptive diagnosis. In this case, during an abdominal CT scan, a 49-year-old female patient was serendipitously found to have a ground-glass infiltrate in the anteromedial segment of the lower lobe of her left lung. Despite presenting with normal lung auscultation on physical examination, the increasing prevalence of subsolid lung nodules, combined with the contemporary era of minimally invasive surgery, prompted the medical team to employ CT-guided harpoon marking for precise lesion localization. Subsequent pathology analysis confirmed the presence of lepidic pattern adenocarcinoma. This case underscores the efficacy of the CT-guided harpoon marking approach, which significantly enhances surgical precision. Such precision is paramount in formulating individualized treatment strategies and follow-up plans for patients with similar clinical presentations.

5.
Front Neural Circuits ; 17: 952921, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37396399

RESUMO

Connectomics is fundamental in propelling our understanding of the nervous system's organization, unearthing cells and wiring diagrams reconstructed from volume electron microscopy (EM) datasets. Such reconstructions, on the one hand, have benefited from ever more precise automatic segmentation methods, which leverage sophisticated deep learning architectures and advanced machine learning algorithms. On the other hand, the field of neuroscience at large, and of image processing in particular, has manifested a need for user-friendly and open source tools which enable the community to carry out advanced analyses. In line with this second vein, here we propose mEMbrain, an interactive MATLAB-based software which wraps algorithms and functions that enable labeling and segmentation of electron microscopy datasets in a user-friendly user interface compatible with Linux and Windows. Through its integration as an API to the volume annotation and segmentation tool VAST, mEMbrain encompasses functions for ground truth generation, image preprocessing, training of deep neural networks, and on-the-fly predictions for proofreading and evaluation. The final goals of our tool are to expedite manual labeling efforts and to harness MATLAB users with an array of semi-automatic approaches for instance segmentation. We tested our tool on a variety of datasets that span different species at various scales, regions of the nervous system and developmental stages. To further expedite research in connectomics, we provide an EM resource of ground truth annotation from four different animals and five datasets, amounting to around 180 h of expert annotations, yielding more than 1.2 GB of annotated EM images. In addition, we provide a set of four pre-trained networks for said datasets. All tools are available from https://lichtman.rc.fas.harvard.edu/mEMbrain/. With our software, our hope is to provide a solution for lab-based neural reconstructions which does not require coding by the user, thus paving the way to affordable connectomics.


Assuntos
Conectoma , Aprendizado Profundo , Animais , Conectoma/métodos , Processamento de Imagem Assistida por Computador/métodos , Software , Algoritmos
6.
Ecol Evol ; 12(2): e8479, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35169444

RESUMO

Population sizes of many birds are declining alarmingly and methods for estimating fluctuations in species' abundances at a large spatial scale are needed. The possibility to derive indicators from the tendency of specific species to co-occur with others has been overlooked. Here, we tested whether the abundance of resident titmice can act as a general ecological indicator of forest bird density in European forests. Titmice species are easily identifiable and have a wide distribution, which makes them potentially useful ecological indicators. Migratory birds often use information on the density of resident birds, such as titmice, as a cue for habitat selection. Thus, the density of residents may potentially affect community dynamics. We examined spatio-temporal variation in titmouse abundance and total bird abundance, each measured as biomass, by using long-term citizen science data on breeding forest birds in Finland and France. We analyzed the variation in observed forest bird density (excluding titmice) in relation to titmouse abundance. In Finland, forest bird density linearly increased with titmouse abundance. In France, forest bird density nonlinearly increased with titmouse abundance, the association weakening toward high titmouse abundance. We then analyzed whether the abundance (measured as biomass) of random species sets could predict forest bird density better than titmouse abundance. Random species sets outperformed titmice as an indicator of forest bird density only in 4.4% and 24.2% of the random draws, in Finland and France, respectively. Overall, the results suggest that titmice could act as an indicator of bird density in Northern European forest bird communities, encouraging the use of titmice observations by even less-experienced observers in citizen science monitoring of general forest bird density.

7.
Dis Model Mech ; 14(4)2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33973627

RESUMO

Synapses are particularly vulnerable in many neurodegenerative diseases and often the first to degenerate, for example in the motor neuron disease spinal muscular atrophy (SMA). Compounds that can counteract synaptic destabilisation are rare. Here, we describe an automated screening paradigm in zebrafish for small-molecule compounds that stabilize the neuromuscular synapse in vivo. We make use of a mutant for the axonal C-type lectin chondrolectin (chodl), one of the main genes dysregulated in SMA. In chodl-/- mutants, neuromuscular synapses that are formed at the first synaptic site by growing axons are not fully mature, causing axons to stall, thereby impeding further axon growth beyond that synaptic site. This makes axon length a convenient read-out for synapse stability. We screened 982 small-molecule compounds in chodl chodl-/- mutants and found four that strongly rescued motor axon length. Aberrant presynaptic neuromuscular synapse morphology was also corrected. The most-effective compound, the adenosine uptake inhibitor drug dipyridamole, also rescued axon growth defects in the UBA1-dependent zebrafish model of SMA. Hence, we describe an automated screening pipeline that can detect compounds with relevance to SMA. This versatile platform can be used for drug and genetic screens, with wider relevance to synapse formation and stabilisation.


Assuntos
Avaliação Pré-Clínica de Medicamentos , Atrofia Muscular Espinal/patologia , Sinapses/patologia , Peixe-Zebra/fisiologia , Animais , Automação , Axônios/efeitos dos fármacos , Axônios/metabolismo , Dipiridamol/farmacologia , Modelos Animais de Doenças , Testes Genéticos , Atrofia Muscular Espinal/genética , Mutação/genética , Fenótipo , Terminações Pré-Sinápticas/patologia , Bibliotecas de Moléculas Pequenas/farmacologia , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
8.
Autophagy ; 17(10): 2939-2961, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33176558

RESUMO

Sterols are a class of lipids critical for fundamental biological processes and membrane dynamics. These molecules are synthesized in the endoplasmic reticulum (ER) and are transported bi-directionally between the ER and plasma membrane (PM). However, the trafficking mechanism of sterols and their relationship with macroautophagy/autophagy are still poorly understood in the rice blast fungus Magnaporthe oryzae. Here, we identified the VAD1 Analog of StAR-related lipid transfer (VASt) domain-containing protein MoVast1 via co-immunoprecipitation in M. oryzae. Loss of MoVAST1 resulted in conidial defects, impaired appressorium development, and reduced pathogenicity. The MoTor (target of rapamycin in M. oryzae) activity is inhibited because MoVast1 deletion leads to high levels of sterol accumulation in the PM. Site-directed mutagenesis showed that the 902 T site is essential for localization and function of MoVast1. Through filipin or Flipper-TR staining, autophagic flux detection, MoAtg8 lipidation, and drug sensitivity assays, we uncovered that MoVast1 acts as a novel autophagy inhibition factor that monitors tension in the PM by regulating the sterol content, which in turn modulates the activity of MoTor. Lipidomics and transcriptomics analyses further confirmed that MoVast1 is an important regulator of lipid metabolism and the autophagy pathway. Our results revealed and characterized a novel sterol transfer protein important for M. oryzae pathogenicity.Abbreviations: AmB: amphotericin B; ATMT: Agrobacterium tumefaciens-mediated transformation; CM: complete medium; dpi: days post-inoculation; ER: endoplasmic reticulum; Flipper-TR: fluorescent lipid tension reporter; GO: Gene ontology; hpi: hours post-inoculation; IH: invasive hyphae; KEGG: kyoto encyclopedia of genes and genomes; MoTor: target of rapamycin in Magnaporthe oryzae; PalmC: palmitoylcarnitine; PM: plasma membrane; SD-N: synthetic defined medium without amino acids and ammonium sulfate; TOR: target of rapamycin; VASt: VAD1 Analog of StAR-related lipid transfer; YFP, yellow fluorescent protein.


Assuntos
Magnaporthe , Oryza , Ascomicetos , Autofagia/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Homeostase , Magnaporthe/genética , Oryza/microbiologia , Doenças das Plantas/microbiologia , Esteróis/metabolismo
9.
Front Cell Dev Biol ; 8: 586296, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33330465

RESUMO

In recent years, zebrafish have become commonly used as a model for studying human traits and disorders. Their small size, high fecundity, and rapid development allow for more high-throughput experiments compared to other vertebrate models. Given that zebrafish share >70% gene homologs with humans and their genomes can be readily edited using highly efficient CRISPR methods, we are now able to rapidly generate mutations impacting practically any gene of interest. Unfortunately, our ability to phenotype mutant larvae has not kept pace. To address this challenge, we have developed a protocol that obtains multiple phenotypic measurements from individual zebrafish larvae in an automated and parallel fashion, including morphological features (i.e., body length, eye area, and head size) and movement/behavior. By assaying wild-type zebrafish in a variety of conditions, we determined optimal parameters that avoid significant developmental defects or physical damage; these include morphological imaging of larvae at two time points [3 days post fertilization (dpf) and 5 dpf] coupled with motion tracking of behavior at 5 dpf. As a proof-of-principle, we tested our approach on two novel CRISPR-generated mutant zebrafish lines carrying predicted null-alleles of syngap1b and slc7a5, orthologs to two human genes implicated in autism-spectrum disorder, intellectual disability, and epilepsy. Using our optimized high-throughput phenotyping protocol, we recapitulated previously published results from mouse and zebrafish models of these candidate genes. In summary, we describe a rapid parallel pipeline to characterize morphological and behavioral features of individual larvae in a robust and consistent fashion, thereby improving our ability to better identify genes important in human traits and disorders.

10.
Acta Psychol (Amst) ; 209: 103133, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32717655

RESUMO

Studies have routinely shown that individuals spend more time spontaneously looking at people or at mimetic scenes that they subsequently judge to be more aesthetically appealing. This "beauty demands longer looks" phenomenon is typically explained by biological relevance, personal utility, or other survival factors, with visual attraction often driven by structural features (symmetry, texture), which may signify fitness and to which most humans tend to respond similarly. However, what of objects that have less overtly adaptive relevance? Here, we consider whether people also look longer at abstract art with little associative/mimetic content that they subsequently rate for higher aesthetic appeal. We employed the "Visual aesthetic sensitivity test" (VAST), which consists of pairs of matched abstract designs with one example of each pair argued to be objectively 'aesthetically better' in regards to low-level features, thus offering a potential contrast between 'objective' (physical feature-based) and 'subjective' (personal taste-based) assessments. Participants (29 women) first looked at image pairs without a specific task and then in three follow-up blocks indicated their preference within the pairs and rated the individual images for liking and for presumed ratings by an art expert. More preferred designs were looked at longer. However, longer looking only occurred in line with participants' subjective tastes. This suggests a general correlation of attention and visual beauty, which-in abstract art-may nonetheless be related to features that are not identified by experts as more generally appealing and thus may not directly map to other (more utility-related) stimuli types.


Assuntos
Atenção , Beleza , Estética , Tecnologia de Rastreamento Ocular , Emoções , Feminino , Humanos
11.
Elife ; 72018 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-29979149

RESUMO

Myelinating oligodendrocytes are essential for central nervous system (CNS) formation and function. Their disruption is implicated in numerous neurodevelopmental, neuropsychiatric and neurodegenerative disorders. However, recent studies have indicated that oligodendrocytes may be tractable for treatment of disease. In recent years, zebrafish have become well established for the study of myelinating oligodendrocyte biology and drug discovery in vivo. Here, by automating the delivery of zebrafish larvae to a spinning disk confocal microscope, we were able to automate high-resolution imaging of myelinating oligodendrocytes in vivo. From there, we developed an image analysis pipeline that facilitated a screen of compounds with epigenetic and post-translational targets for their effects on regulating myelinating oligodendrocyte number. This screen identified novel compounds that strongly promote myelinating oligodendrocyte formation in vivo. Our imaging platform and analysis pipeline is flexible and can be employed for high-resolution imaging-based screens of broad interest using zebrafish.


Assuntos
Testes Genéticos , Bainha de Mielina/metabolismo , Peixe-Zebra/genética , Animais , Animais Geneticamente Modificados , Automação , Contagem de Células , Fluorescência , Ensaios de Triagem em Larga Escala , Processamento de Imagem Assistida por Computador , Larva/metabolismo , Naftalenos/farmacologia , Oligodendroglia/citologia , Pironas/farmacologia , Reprodutibilidade dos Testes , Medula Espinal/metabolismo , Imagem com Lapso de Tempo
12.
Psychon Bull Rev ; 24(6): 1870-1878, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28321819

RESUMO

"Vast" is a word often applied to environmental terrain that is perceived to have large spatial extent. This judgment is made even at viewing distances where traditional metric depth cues are not useful. This paper explores the perceptual basis of vast experience, including reliability and visual precursors. Experiment 1 demonstrated strong agreement in ratings of the spatial extent of two-dimensional (2D) scene images by participants in two countries under very different viewing conditions. Image categories labeled "vast" often exemplified scene attributes of ruggedness and openness (Oliva & Torralba, 2001). Experiment 2 quantitatively assessed whether these properties predict vastness. High vastness ratings were associated with highly open, or moderately open but rugged, scenes. Experiment 3 provided evidence, consistent with theory, that metric distance perception does not directly mediate the observed vastness ratings. The question remains as to how people perceive vast space when information about environmental scale is unavailable from metric depth cues or associated scene properties. We consider possible answers, including contribution from strong cues to relative depth.


Assuntos
Percepção de Distância/fisiologia , Percepção Visual/fisiologia , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
13.
Eur J Psychotraumatol ; 8(1): 1389207, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29163864

RESUMO

Background: It is well established that veterans suffering from mental health difficulties under use mental health services. Objective: This study aimed to understand more about the barriers that prevent veterans from seeking professional help and the enablers that assist veterans in seeking professional help. It also aimed to explore potential mechanisms to improve veterans' help-seeking and pathways to care. Method: The study employed a qualitative design whereby 17 veterans who had recently attended specialist veteran mental health services took part in semi-structured interviews. The resultant data were analysed using grounded theory. Results: Participants described two distinct stages to their help-seeking: initial help-seeking and pathways through treatment. Specific barriers and enablers to help-seeking were identified at each stage. Initial barriers included recognizing that there is a problem, self-stigma and anticipated public stigma. Initial enablers included being in crisis, social support, motivation and the media. Treatment pathway barriers included practical factors and negative beliefs about health services and professionals. Treatment pathway enablers included having a diagnosis, being seen in a veteran-specific service and establishing a good therapeutic relationship. Participants provided some suggestions for interventions to improve veterans' help-seeking in future; these focussed on enhancing both veterans and health professionals' knowledge regarding mental health difficulties. Conclusions: This study identified a number of barriers and enablers that may impact a veteran's journey in seeking help from professional services for mental health difficulties. Enablers such as reaching a crisis point, social support, the media, having a diagnosis of PTSD and veteran-specific mental health services appeared to be important in opposing stigma-related beliefs and in supporting veterans to engage in help-seeking behaviours.


Planteamiento: Está bien establecido que los veteranos que sufren de problemas de salud mental infrautilizan los servicios de salud mental. Objetivo: Este estudio estaba dirigido a comprender más sobre las barreras que impiden que los veteranos busquen ayuda profesional y aquello que les facilita su búsqueda de ayuda profesional. También tenía como objetivo explorar posibles mecanismos para mejorar la búsqueda de ayuda y las vías que llevan a dicha atención de los veteranos. Método: El estudio empleó un diseño cualitativo mediante el cual 17 veteranos, que habían asistido recientemente a servicios especializados de salud mental para veteranos, participaron en entrevistas semiestructuradas. Los datos resultantes se analizaron utilizando una teoría fundamentada. Resultados: Los participantes describieron dos etapas distintas en su búsqueda de ayuda: búsqueda inicial de ayuda; y vías del tratamiento. En cada etapa se identificaron las barreras específicas y los facilitadores para dicha búsqueda de ayuda. Las barreras iniciales incluyeron el reconocimiento de que existe un problema, el autoestigma y el estigma público anticipado. Los facilitadores iniciales incluyeron estar en crisis, apoyo social, motivación y los medios de comunicación. Las barreras a recibir tratamiento incluían factores prácticos y creencias negativas sobre los servicios de salud y los profesionales. Lo que facilitaba el recibir tratamiento incluía tener un diagnóstico, ser vistos en un servicio específico para veteranos y establecer una buena relación terapéutica. Los participantes proporcionaron algunas sugerencias de intervenciones para mejorar la búsqueda de ayuda de los veteranos en el futuro; estos se enfocaron en mejorar el conocimiento sobre las dificultades de salud mental. tanto de los veteranos como el de los profesionales de la salud. Conclusiones: Este estudio identificó una serie de barreras y facilitadores que pueden influir en que los veteranos busquen ayuda de servicios profesionales para las dificultades de salud mental. Facilitadores como llegar a un punto de crisis, el apoyo social, los medios de comunicación, tener un diagnóstico de TEPT y servicios de salud mental específicos para veteranos parecían ser importantes a la hora de enfrentarse a creencias estigmatizadas y de apoyar a los veteranos a implicarse en conductas de búsqueda de ayuda.

14.
Sci Total Environ ; 526: 136-52, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-25931023

RESUMO

To properly manage our natural and managed landscapes, and to restore or repair degraded areas, it is important to know the changes that have taken place over time, particularly with respect to land use and its cumulative effect on ecological function. In common with many places in the world, where the industrial revolution resulted in profound changes to land use and management, Australia's landscapes have been transformed in the last 200 years. Initially the VAST (Vegetation Assets, States and Transitions) system was developed to describe and map changes in vegetation over time through a series of condition states or classes; here we describe an enhancement to the VAST method which will enable identification of the factors contributing to those changes in state as a result of changes in management practice. The 'VAST-2' system provides a structure in which to compile, interpret and sequence a range of data about past management practices, their effect on site and vegetation condition. Alongside a systematic chronology of land use and management, a hierarchy of indices is used to build a picture of the condition of the vegetation through time: 22 indicators within ten criteria representing three components of vegetation condition-regenerative capacity, vegetation structure and species composition-are scored using information from a variety of sources. These indicators are assessed relative to a pre-European reference state, either actual or synthetic. Each component is weighted proportionally to its contribution to the whole, determined through expert opinion. These weighted condition components are used to produce an aggregated transformation score for the vegetation. The application of this system to a range of sites selected across Australia's tropical, sub-tropical and temperate bioregions is presented, illustrating the utility of the system. Notably, the method accommodates a range of different types of information to be aggregated.

15.
Sci Total Environ ; 534: 14-30, 2015 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-26170116

RESUMO

To properly manage our natural and managed landscapes, and to restore or repair degraded areas, it is important to know the changes that have taken place over time, particularly with respect to land use and its cumulative effect on ecological function. In common with many places in the world, where the industrial revolution resulted in profound changes to land use and management, Australia's landscapes have been transformed in the last 200 years. Initially the VAST (Vegetation Assets, States and Transitions) system was developed to describe and map changes in vegetation over time through a series of condition states or classes; here we describe an enhancement to the VAST method which will enable identification of the factors contributing to those changes in state as a result of changes in management practice. The 'VAST-2' system provides a structure in which to compile, interpret and sequence a range of data about past management practices, their effect on site and vegetation condition. Alongside a systematic chronology of land use and management, a hierarchy of indices is used to build a picture of the condition of the vegetation through time: 22 indicators within ten criteria representing three components of vegetation condition-regenerative capacity, vegetation structure and species composition-are scored using information from a variety of sources. These indicators are assessed relative to a pre-European reference state, either actual or synthetic. Each component is weighted proportionally to its contribution to the whole, determined through expert opinion. These weighted condition components are used to produce an aggregated transformation score for the vegetation. The application of this system to a range of sites selected across Australia's tropical, sub-tropical and temperate bioregions is presented, illustrating the utility of the system. Notably, the method accommodates a range of different types of information to be aggregated.

16.
Elife ; 42015 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-26001273

RESUMO

Sterol traffic between the endoplasmic reticulum (ER) and plasma membrane (PM) is a fundamental cellular process that occurs by a poorly understood non-vesicular mechanism. We identified a novel, evolutionarily diverse family of ER membrane proteins with StART-like lipid transfer domains and studied them in yeast. StART-like domains from Ysp2p and its paralog Lam4p specifically bind sterols, and Ysp2p, Lam4p and their homologs Ysp1p and Sip3p target punctate ER-PM contact sites distinct from those occupied by known ER-PM tethers. The activity of Ysp2p, reflected in amphotericin-sensitivity assays, requires its second StART-like domain to be positioned so that it can reach across ER-PM contacts. Absence of Ysp2p, Ysp1p or Sip3p reduces the rate at which exogenously supplied sterols traffic from the PM to the ER. Our data suggest that these StART-like proteins act in trans to mediate a step in sterol exchange between the PM and ER.


Assuntos
Proteínas de Transporte/metabolismo , Membrana Celular/metabolismo , Retículo Endoplasmático/metabolismo , Proteínas Mitocondriais/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Esteróis/metabolismo , Transporte Biológico/fisiologia , Biologia Computacional , Células HL-60 , Humanos , Plasmídeos/genética , Reação em Cadeia da Polimerase
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