43 research outputs found
Evaluation of wheat products with high flavonoid content: justification of importance of marker-assisted development and production of flavonoid-rich wheat cultivars
In the structure of the global commodity supply in the food market in modern conditions it is necessary to note the emergence of a broad group of new high-tech products, and specialized functional food with high value added. The creation of varieties with a high content of flavonoids (plant compounds that can have a positive effect on human health) is one of the important directions of plant breeding oriented on the functional foods development. Currently, however, there is a significant gap between the well-studied role of flavonoids and the genetic control of their synthesis, on the one hand, and development of the actual product of wheat with new properties, evaluation of the nutritional value of the end-use bakery products for consumption, on the other hand. In the present study we produced and investigated bakery products from wheat synthesizing bioflavonoid pigments anthocyanins in the grain pericarp. The grains of this wheat have dark purple color. Red-grained bread wheat was a control. These two wheat lines have almost similar genomes with the exception of a small part of chromosome 2A, which contains the Pp3/TaMyc1 gene regulating anthocyanin biosynthesis. The use of such an accurate model has allowed relating the observed differences precisely with anthocyanin biosynthesis. The important task was to evaluate the resistance of anthocyanins to the backing process. Therefore anthocyanin content was evaluated not only in the end-use product, but also in mixtures of flour and bran used for baking and separately in the bran. As a result, significant differences were detected in samples obtained from purple grains, compared with the control including the products that had passed a full processing cycle, including baking at elevated temperature. For the extraction of anthocyanins conditions were simulated most similar to those in the process of digestion in the stomach, in order to assess the amount of assimilable anthocyanins. By our estimates one can get up to 1.03 mg of assimilable anthocyanins with 100 g of whole-grained bread produced from anthocyanincolored grains. With 100 g of bran, the body will get up to 3.32 g of anthocyanins. In parallel with the evaluation of the anthocyanins content in all samples, the mass fraction of antioxidants was measured by using the amperometric method. The highest antioxidant capacity was shown for bran, while the least one was demonstrated for flour. Adding bran to the flour as well as the backing process increased the antioxidant capacity of wheat products. The contribution of anthocyanins to increased antioxidant capacity is not significant. It was shown that bread-making quality and organoleptic properties of bakery products made from anthocyanin-colored grains did not concede, or in some cases were higher than the corresponding properties of products obtained from control NIL grains. It was found that the presence of anthocyanin increases the shelf life of bakery products and their resistance to molding in provocative conditions. These results, combined with the known data about the beneficial health effects of anthocyanins, suggest that wheat bakery products made from anthocyanin-rich grains can be included to the list for dietary food. Marker-assisted selection accelerating the creation of new forms of crops with a high level of flavonoids can be proposed as a new direction for the expansion of domestic and export grain market potential due to the new possibilities of obtaining products of increased nutritional value and making a good profit
Beyond Hebb: Exclusive-OR and Biological Learning
A learning algorithm for multilayer neural networks based on biologically
plausible mechanisms is studied. Motivated by findings in experimental
neurobiology, we consider synaptic averaging in the induction of plasticity
changes, which happen on a slower time scale than firing dynamics. This
mechanism is shown to enable learning of the exclusive-OR (XOR) problem without
the aid of error back-propagation, as well as to increase robustness of
learning in the presence of noise.Comment: 4 pages RevTeX, 2 figures PostScript, revised versio
Kainate Receptor-Mediated Modulation of Hippocampal Fast Spiking Interneurons in a Rat Model of Schizophrenia
Kainate receptor (KAR) subunits are believed to be involved in abnormal GABAergic neurotransmission in the hippocampus (HIPP) in schizophrenia (SZ) and bipolar disorder. Postmortem studies have shown changes in the expression of the GluR5/6 subunits of KARs in the stratum oriens (SO) of sectors CA2/3, where the basolateral amygdala (BLA) sends a robust projection. Previous work using a rat model of SZ demonstrated that BLA activation leads to electrophysiological changes in fast-spiking interneurons in SO of CA2/3. The present study explores KAR modulation of interneurons in CA2/3 in response to BLA activation. Intrinsic firing properties of these interneurons through KAR-mediated activity were measured with patch-clamp recordings from rats that received 15 days of picrotoxin infusion into the BLA. Chronic BLA activation induced changes in the firing properties of CA2/3 interneurons associated with modifications in the function of KARs. Specifically, the responsiveness of these interneurons to activation of KARs was diminished in picrotoxin-treated rats, while the after-hyperpolarization (AHP) amplitude was increased. In addition, we tested blockers of KAR subunits which have been shown to have altered gene expression in SO sector CA2/3 of SZ subjects. The GluR5 antagonist UBP296 further decreased AP frequency and increased AHP amplitude in picrotoxin-treated rats. Application of the GluR6/7 antagonist NS102 suggested that activation of GluR6/7 KARs may be required to maintain the high firing rates in SO interneurons in the presence of KA. Moreover, the GluR6/7 KAR-mediated signaling may be suppressed in PICRO-treated rats. Our findings indicate that glutamatergic activity from the BLA may modulate the firing properties of CA2/3 interneurons through GluR5 and GluR6/7 KARs. These receptors are expressed in GABAergic interneurons and play a key role in the synchronization of gamma oscillations. Modulation of interneuronal activity through KARs in response to amygdala activation may lead to abnormal oscillatory rhythms reported in SZ subjects
Announced reward counteracts the effects of chronic social stress on anticipatory behavior and hippocampal synaptic plasticity in rats
Multi-label classification for biomedical literature: an overview of the BioCreative VII LitCovid Track for COVID-19 literature topic annotations
The coronavirus disease 2019 (COVID-19) pandemic has been severely impacting global society since December 2019. The related findings such as vaccine and drug development have been reported in biomedical literatureâat a rate of about 10â000 articles on COVID-19 per month. Such rapid growth significantly challenges manual curation and interpretation. For instance, LitCovid is a literature database of COVID-19-related articles in PubMed, which has accumulated more than 200â000 articles with millions of accesses each month by users worldwide. One primary curation task is to assign up to eight topics (e.g. Diagnosis and Treatment) to the articles in LitCovid. The annotated topics have been widely used for navigating the COVID literature, rapidly locating articles of interest and other downstream studies. However, annotating the topics has been the bottleneck of manual curation. Despite the continuing advances in biomedical text-mining methods, few have been dedicated to topic annotations in COVID-19 literature. To close the gap, we organized the BioCreative LitCovid track to call for a community effort to tackle automated topic annotation for COVID-19 literature. The BioCreative LitCovid datasetâconsisting of over 30â000 articles with manually reviewed topicsâwas created for training and testing. It is one of the largest multi-label classification datasets in biomedical scientific literature. Nineteen teams worldwide participated and made 80 submissions in total. Most teams used hybrid systems based on transformers. The highest performing submissions achieved 0.8875, 0.9181 and 0.9394 for macro-F1-score, micro-F1-score and instance-based F1-score, respectively. Notably, these scores are substantially higher (e.g. 12%, higher for macro F1-score) than the corresponding scores of the state-of-art multi-label classification method. The level of participation and results demonstrate a successful track and help close the gap between dataset curation and method development. The dataset is publicly available via https://ftp.ncbi.nlm.nih.gov/pub/lu/LitCovid/biocreative/ for benchmarking and further development.
Database URLhttps://ftp.ncbi.nlm.nih.gov/pub/lu/LitCovid/biocreative/</p
Developmental regulation of expression of schizophrenia susceptibility genes in the primate hippocampal formation
The hippocampal formation is essential for normal memory function and is implicated in many neurodevelopmental, neurodegenerative and neuropsychiatric disorders. In particular, abnormalities in hippocampal structure and function have been identified in schizophrenic subjects. Schizophrenia has a strong polygenic component, but the role of numerous susceptibility genes in normal brain development and function has yet to be investigated. Here we described the expression of schizophrenia susceptibility genes in distinct regions of the monkey hippocampal formation during early postnatal development. We found that, as compared with other genes, schizophrenia susceptibility genes exhibit a differential regulation of expression in the dentate gyrus, CA3 and CA1, over the course of postnatal development. A number of these genes involved in synaptic transmission and dendritic morphology exhibit a developmental decrease of expression in CA3. Abnormal CA3 synaptic organization observed in schizophrenics might be related to some specific symptoms, such as loosening of association. Interestingly, changes in gene expression in CA3 might occur at a time possibly corresponding to the late appearance of the first clinical symptoms. We also found earlier changes in expression of schizophrenia susceptibility genes in CA1, which might be linked to prodromal psychotic symptoms. A number of schizophrenia susceptibility genes including APOE, BDNF, MTHFR and SLC6A4 are involved in other disorders, and thus likely contribute to nonspecific changes in hippocampal structure and function that must be combined with the dysregulation of other genes in order to lead to schizophrenia pathogenesis