413 research outputs found
Применение метода проектов для формирования знаний о природе у детей дошкольного возраста
В ВКР представлено одно из средств формирования экологического образования у детей дошкольного возраста метод проектов. Это дидактическое средство активизации познавательного и творческого развития ребенка и одновременно формирование его личностных качеств. Знания, приобретаемые детьми в ходе метода проектов, становятся достоянием их личного опыта. Экспериментируя, ребенок ищет ответ на вопрос и тем самым, развивает творческие способности, коммуникативные навыки. Экологическое образование детей дошкольного возраста – это многоаспектное качество, включающее в себя экологические представления и знания ребенка о пользе природе и всего живого, понимание детьми элементарных взаимосвязей, существующих в природе, умения и навыки эмоционально-чувственного взаимодействия с природными объектами и гуманно-действенного взаимодействия человека с ней. Эффективным средством формирования знаний о природе у детей дошкольного возраста является использование метода проектов, цель которого – посредством познавательно-исследовательской деятельности, которая организуется во взаимодействии с детьми и экологические представления и знания, положительное эмоциональное отношение к природе
Transcriptome profiling of grapevine seedless segregants during berry development reveals candidate genes associated with berry weight
Indexación: Web of Science; PubMedBackground
Berry size is considered as one of the main selection criteria in table grape breeding programs. However, this is a quantitative and polygenic trait, and its genetic determination is still poorly understood. Considering its economic importance, it is relevant to determine its genetic architecture and elucidate the mechanisms involved in its expression. To approach this issue, an RNA-Seq experiment based on Illumina platform was performed (14 libraries), including seedless segregants with contrasting phenotypes for berry weight at fruit setting (FST) and 6–8 mm berries (B68) phenological stages.
Results
A group of 526 differentially expressed (DE) genes were identified, by comparing seedless segregants with contrasting phenotypes for berry weight: 101 genes from the FST stage and 463 from the B68 stage. Also, we integrated differential expression, principal components analysis (PCA), correlations and network co-expression analyses to characterize the transcriptome profiling observed in segregants with contrasting phenotypes for berry weight. After this, 68 DE genes were selected as candidate genes, and seven candidate genes were validated by real time-PCR, confirming their expression profiles.
Conclusions
We have carried out the first transcriptome analysis focused on table grape seedless segregants with contrasting phenotypes for berry weight. Our findings contributed to the understanding of the mechanisms involved in berry weight determination. Also, this comparative transcriptome profiling revealed candidate genes for berry weight which could be evaluated as selection tools in table grape breeding programs.http://bmcplantbiol.biomedcentral.com/articles/10.1186/s12870-016-0789-
Gravitational waves from single neutron stars: an advanced detector era survey
With the doors beginning to swing open on the new gravitational wave
astronomy, this review provides an up-to-date survey of the most important
physical mechanisms that could lead to emission of potentially detectable
gravitational radiation from isolated and accreting neutron stars. In
particular we discuss the gravitational wave-driven instability and
asteroseismology formalism of the f- and r-modes, the different ways that a
neutron star could form and sustain a non-axisymmetric quadrupolar "mountain"
deformation, the excitation of oscillations during magnetar flares and the
possible gravitational wave signature of pulsar glitches. We focus on progress
made in the recent years in each topic, make a fresh assessment of the
gravitational wave detectability of each mechanism and, finally, highlight key
problems and desiderata for future work.Comment: 39 pages, 12 figures, 2 tables. Chapter of the book "Physics and
Astrophysics of Neutron Stars", NewCompStar COST Action 1304. Minor
corrections to match published versio
NGTS-11 b (TOI-1847 b): A Transiting Warm Saturn Recovered from a TESS Single-transit Event
We report the discovery of NGTS-11 b (=TOI-1847 b), a transiting Saturn in a
35.46-day orbit around a mid K-type star (Teff=5050 K). We initially identified
the system from a single-transit event in a TESS full-frame image light-curve.
Following seventy-nine nights of photometric monitoring with an NGTS telescope,
we observed a second full transit of NGTS-11 b approximately one year after the
TESS single-transit event. The NGTS transit confirmed the parameters of the
transit signal and restricted the orbital period to a set of 13 discrete
periods. We combined our transit detections with precise radial velocity
measurements to determine the true orbital period and measure the mass of the
planet. We find NGTS-11 b has a radius of 0.817+0.028-0.032 , a mass of
0.344+0.092-0.073 , and an equilibrium temperature of just 435+34-32 K,
making it one of the coolest known transiting gas giants. NGTS-11 b is the
first exoplanet to be discovered after being initially identified as a TESS
single-transit event, and its discovery highlights the power of intense
photometric monitoring in recovering longer-period transiting exoplanets from
single-transit events
Drivers of reef shark abundance and biomass in the Solomon Islands
Remote island nations face a number of challenges in addressing concerns about shark population status, including access to rigorously collected data and resources to manage fisheries. At present, very little data are available on shark populations in the Solomon Islands and scientific surveys to document shark and ray diversity and distribution have not been completed. We aimed to provide a baseline of the relative abundance and diversity of reef sharks and rays and assess the major drivers of reef shark abundance/biomass in the Western Province of the Solomon Islands using stereo baited remote underwater video. On average reef sharks were more abundant than in surrounding countries such as Fiji and Indonesia, yet below that of remote islands without historical fishing pressure, suggesting populations are relatively healthy but not pristine. We also assessed the influence of location, habitat type/complexity, depth and prey biomass on reef shark abundance and biomass. Location was the most important factor driving reef shark abundance and biomass with two times the abundance and a 43% greater biomass of reef sharks in the more remote locations, suggesting fishing may be impacting sharks in some areas. Our results give a much needed baseline and suggest that reef shark populations are still relatively unexploited, providing an opportunity for improved management of sharks and rays in the Solomon Islands
An ultrahot Neptune in the Neptune desert
About one out of 200 Sun-like stars has a planet with an orbital period
shorter than one day: an ultra-short-period planet (Sanchis-ojeda et al. 2014;
Winn et al. 2018). All of the previously known ultra-short-period planets are
either hot Jupiters, with sizes above 10 Earth radii (Re), or apparently rocky
planets smaller than 2 Re. Such lack of planets of intermediate size (the "hot
Neptune desert") has been interpreted as the inability of low-mass planets to
retain any hydrogen/helium (H/He) envelope in the face of strong stellar
irradiation. Here, we report the discovery of an ultra-short-period planet with
a radius of 4.6 Re and a mass of 29 Me, firmly in the hot Neptune desert. Data
from the Transiting Exoplanet Survey Satellite (Ricker et al. 2015) revealed
transits of the bright Sun-like star \starname\, every 0.79 days. The planet's
mean density is similar to that of Neptune, and according to thermal evolution
models, it has a H/He-rich envelope constituting 9.0^(+2.7)_(-2.9)% of the
total mass. With an equilibrium temperature around 2000 K, it is unclear how
this "ultra-hot Neptune" managed to retain such an envelope. Follow-up
observations of the planet's atmosphere to better understand its origin and
physical nature will be facilitated by the star's brightness (Vmag=9.8)
pitx2 Deficiency Results in Abnormal Ocular and Craniofacial Development in Zebrafish
Human PITX2 mutations are associated with Axenfeld-Rieger syndrome, an autosomal-dominant developmental disorder that involves ocular anterior segment defects, dental hypoplasia, craniofacial dysmorphism and umbilical abnormalities. Characterization of the PITX2 pathway and identification of the mechanisms underlying the anomalies associated with PITX2 deficiency is important for better understanding of normal development and disease; studies of pitx2 function in animal models can facilitate these analyses. A knockdown of pitx2 in zebrafish was generated using a morpholino that targeted all known alternative transcripts of the pitx2 gene; morphant embryos generated with the pitx2ex4/5 splicing-blocking oligomer produced abnormal transcripts predicted to encode truncated pitx2 proteins lacking the third (recognition) helix of the DNA-binding homeodomain. The morphological phenotype of pitx2ex4/5 morphants included small head and eyes, jaw abnormalities and pericardial edema; lethality was observed at ∼6–8-dpf. Cartilage staining revealed a reduction in size and an abnormal shape/position of the elements of the mandibular and hyoid pharyngeal arches; the ceratobranchial arches were also decreased in size. Histological and marker analyses of the misshapen eyes of the pitx2ex4/5 morphants identified anterior segment dysgenesis and disordered hyaloid vasculature. In summary, we demonstrate that pitx2 is essential for proper eye and craniofacial development in zebrafish and, therefore, that PITX2/pitx2 function is conserved in vertebrates
SINE RNA Induces Severe Developmental Defects in Arabidopsis thaliana and Interacts with HYL1 (DRB1), a Key Member of the DCL1 Complex
The proper temporal and spatial expression of genes during plant development is governed, in part, by the regulatory activities of various types of small RNAs produced by the different RNAi pathways. Here we report that transgenic Arabidopsis plants constitutively expressing the rapeseed SB1 SINE retroposon exhibit developmental defects resembling those observed in some RNAi mutants. We show that SB1 RNA interacts with HYL1 (DRB1), a double-stranded RNA-binding protein (dsRBP) that associates with the Dicer homologue DCL1 to produce microRNAs. RNase V1 protection assays mapped the binding site of HYL1 to a SB1 region that mimics the hairpin structure of microRNA precursors. We also show that HYL1, upon binding to RNA substrates, induces conformational changes that force single-stranded RNA regions to adopt a structured helix-like conformation. Xenopus laevis ADAR1, but not Arabidopsis DRB4, binds SB1 RNA in the same region as HYL1, suggesting that SINE RNAs bind only a subset of dsRBPs. Consistently, DCL4-DRB4-dependent miRNA accumulation was unchanged in SB1 transgenic Arabidopsis, whereas DCL1-HYL1-dependent miRNA and DCL1-HYL1-DCL4-DRB4-dependent tasiRNA accumulation was decreased. We propose that SINE RNA can modulate the activity of the RNAi pathways in plants and possibly in other eukaryotes
Genomic and Transcriptional Co-Localization of Protein-Coding and Long Non-Coding RNA Pairs in the Developing Brain
Besides protein-coding mRNAs, eukaryotic transcriptomes include many long non-protein-coding RNAs (ncRNAs) of unknown function that are transcribed away from protein-coding loci. Here, we have identified 659 intergenic long ncRNAs whose genomic sequences individually exhibit evolutionary constraint, a hallmark of functionality. Of this set, those expressed in the brain are more frequently conserved and are significantly enriched with predicted RNA secondary structures. Furthermore, brain-expressed long ncRNAs are preferentially located adjacent to protein-coding genes that are (1) also expressed in the brain and (2) involved in transcriptional regulation or in nervous system development. This led us to the hypothesis that spatiotemporal co-expression of ncRNAs and nearby protein-coding genes represents a general phenomenon, a prediction that was confirmed subsequently by in situ hybridisation in developing and adult mouse brain. We provide the full set of constrained long ncRNAs as an important experimental resource and present, for the first time, substantive and predictive criteria for prioritising long ncRNA and mRNA transcript pairs when investigating their biological functions and contributions to development and disease
A fluorogenic cyclic peptide for imaging and quantification of drug-induced apoptosis
Programmed cell death or apoptosis is a central biological process that is dysregulated in many diseases, including inflammatory conditions and cancer. The detection and quantification of apoptotic cells in vivo is hampered by the need for fixatives or washing steps for non-fluorogenic reagents, and by the low levels of free calcium in diseased tissues that restrict the use of annexins. In this manuscript, we report the rational design of a highly stable fluorogenic peptide (termed Apo-15) that selectively stains apoptotic cells in vitro and in vivo in a calcium-independent manner and under wash-free conditions. Furthermore, using a combination of chemical and biophysical methods, we identify phosphatidylserine as a molecular target of Apo-15. We demonstrate that Apo-15 can be used for the quantification and imaging of drug-induced apoptosis in preclinical mouse models, thus creating opportunities for assessing the in vivo efficacy of anti-inflammatory and anti-cancer therapeutics
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