bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimating the number of protein molecules in a plant cell: a quantitative perspective on proteostasis and amino acid homeostasis during progressive drought stress
Authors: Heinemann Björn , Künzler Patrick , Braun Hans-Peter , Hildebrandt Tatjana M. 
Published: March 2020

AbstractDuring dehydration cellular proteostasis as well as amino acid homeostasis are severely challenged, since the decrease in photosynthesis induces massive proteolysis. Thus, we selected progressive drought stress inArabidopsis thalianaas a model to investigate the balance between protein and free amino acid homeostasis on a quantitative level. We analyze the mass protein composition of rosette leaves and estimate, how many protein molecules are present in a plant cell and its subcellular compartments. Under control conditions, an average Arabidopsis mesophyll cell contains about 25 billion protein molecules and 80% of them are localized in the chloroplasts. Severe water deficiency leads to degradation of more than 40% of the leaf proteome and thus causes a drastic shift towards the free amino acid pool. Stress induced proteolysis of half of the 400 million RubisCO hexadecamers present in the chloroplasts of an individual mesophyll cell alone doubles the cellular content in free amino acids. A major fraction of the amino acids released from proteins is channeled into the synthesis of proline as a compatible osmolyte. Complete oxidation of the remaining part as an alternative respiratory substrate can fully compensate the lack of carbohydrates derived from photosynthesis for several hours.
Biomechanical properties of a buzz-pollinated flower
Authors: Garcia Brito Vinicius Lourenço , Pereira Nunes Carlos Eduardo , Rocha Resende Caique , Montealegre-Zapata Fernando , Vallejo-Marín Mario 
Published: March 2020

AbstractApproximately half of all bee species use vibrations to remove pollen from plants with diverse floral morphologies. In many buzz-pollinated flowers, these mechanical vibrations generated by bees are transmitted through floral tissues, principally pollen-containing anthers, causing pollen to be ejected from small openings (pores or slits) at the tip of the stamen. Despite the importance of substrate-borne vibrations for both bees and plants, few studies to date have characterised the transmission properties of floral vibrations. In this study, we use contactless laser vibrometry to evaluate the transmission of vibrations in the corolla and anthers of buzz-pollinated flowers ofSolanum rostratum, and measured vibrations in three spatial axes. We found that floral vibrations conserve their dominant frequency (300Hz) as they are transmitted through the flower, but that vibrations in anthers and petals can gain additional harmonics relative to the pure tone of input vibrations. We also found that vibrations are generally amplified (up to >400%) as they travel from the receptacle at the base of the flower to other floral structures, and that anthers vibrate with a higher amplitude velocity than petals. Together, these results suggest that vibrations travel differently through floral structures and across different spatial axes. As pollen release is a function of vibration amplitude, we conjecture that bees might benefit from applying vibrations in the axes associated with higher vibration amplification.
A role for the cortex in sleep-wake regulation
Authors: Krone Lukas B. , Yamagata Tomoko , Blanco-Duque Cristina , Guillaumin Mathilde C. C. , Kahn Martin C. , Akerman Colin J. , Hoerder-Suabedissen Anna , Molnár Zoltán , Vyazovskiy Vladyslav V. 
Published: March 2020

AbstractThe cortex and subcortical circuitry are thought to play distinct roles in the generation of sleep oscillations and global control of vigilance states. Here we silenced a subset of cortical layer 5 pyramidal and dentate gyrus granule cells in mice using a cell-specific ablation of the key t-SNARE protein SNAP25. We found a marked increase in wakefulness accompanied by a reduced rebound of EEG slow-wave activity after sleep deprivation. Our data illustrates an important role for the cortex in both global state control and sleep homeostasis.
Opa1overexpression protects from early onsetMpv17-/--related mouse kidney disease
Authors: Luna-Sanchez Marta , Benincà Cristiane , Cerutti Raffaele , Brea-Calvo Gloria , Yeates Anna , Scorrano Luca , Zeviani Massimo , Viscomi Carlo 
Published: March 2020

AbstractModerate overexpression ofOpa1, encoding a master regulator of mitochondrial cristae morphology, has been shown to improve significantly mitochondrial damage induced by drugs, surgical denervation, or genetically determined OXPHOS defects. However, this approach has been so far demonstrated in a limited number of genetically defective OXPHOS models characterized by specific impairment of a single mitochondrial respiratory chain complex. Here, we investigated the effectiveness of moderateOpa1overexpression in theMpv17-/-mouse, characterized by profound, multisystem mtDNA depletion. In naïveMpv17-/-individuals, whose genetic background was crossed with individuals belonging to theOpa1tgstrain, we found a surprising anticipation of severe, progressive focal segmental glomerulosclerosis, previously described inMpv17-/-animals as a late-onset clinical feature (after 12-18 months of life). In contrast, kidney failure ledMpv17-/-individuals from this new “mixed” strain leading to death 8-9 weeks after birth. However,Mpv17-/-::Opa1tgmice lived much longer thanMpv17-/-littermates, and developed much later severe proteinuria associated with focal segmental glomerulosclerosis. MtDNA content and OXPHOS activities were significantly higher inMpv17-/-::Opa1tgthan inMpv17-/-kidneys, and similar to WT littermates. Mitochondrial network and cristae ultrastructure were largely preserved inMpv17-/-::Opa1tgvs.Mpv17-/-kidney and isolated podocytes. Mechanistically, the protective effect ofOpa1overexpression in this model was mediated by a block in apoptosis due to the stabilization of the mitochondrial cristae, consequently increasing the levels of mitochondrial morphology proteins like MFN2 and MIC19 as well as stabilizing ATP synthase oligomers. These results demonstrate that strategies aiming at increasingOpa1expression or activity can be an effective aid against mtDNA depletion syndromes.
Spontaneous retinal waves generate long-range horizontal connectivity in visual cortex
Authors: Kim Jinwoo , Song Min , Paik Se-Bum 
Published: March 2020

AbstractIn the primary visual cortex (V1) of higher mammals, long-range horizontal connections (LHCs) are observed to develop, linking iso-orientation domains of cortical tuning. It is unknown how this feature-specific wiring of circuitry develops before eye opening. Here, we show that LHCs in V1 may originate from spatio-temporally structured feedforward activities generated from spontaneous retinal waves. Using model simulations based on the anatomy and observed activity patterns of the retina, we show that waves propagating in retinal mosaics can initialize the wiring of LHCs by co-activating neurons of similar tuning, whereas equivalent random activities cannot induce such organizations. Simulations showed that emerged LHCs can produce the patterned activities observed in V1, matching topography of the underlying orientation map. We also confirmed that the model can also reproduce orientation-specific microcircuits in salt-and-pepper organizations in rodents. Our results imply that early peripheral activities contribute significantly to cortical development of functional circuits.HighlightsDevelopmental model of long-range horizontal connections (LHCs) in V1 is simulatedSpontaneous retinal waves generate feature-specific wiring of LHCs in visual cortexEmerged LHCs induce orientation-matching patterns of spontaneous cortical activityRetinal waves induce orientation-specific microcircuits of visual cortex in rodentsSignificance statementLong-range horizontal connections (LHCs) in the primary visual cortex (V1) are observed to emerge before the onset of visual experience, selectively connecting iso-domains of orientation maps. However, it is unknown how such tuning-specific wirings develop before eye-opening. Here, we show that LHCs in V1 originate from the tuning-specific activation of cortical neurons by spontaneous retinal waves during early developmental stages. Our simulations of a visual cortex model show that feedforward activities from the retina initialize the spatial organization of activity patterns in V1, which induces visual feature-specific wirings of V1 neurons. Our model also explains the origin of cortical microcircuits observed in rodents, suggesting that the proposed developmental mechanism is applicable universally to circuits of various mammalian species.
Robust HIV-1 replication in the absence of integrase function
Authors: Irwan Ishak D. , Karnowski Heather L. , Bogerd Hal P. , Tsai Kevin , Cullen Bryan R. 
Published: March 2020

AbstractIntegration of the proviral DNA intermediate into the host cell genome represents an essential step in the retroviral life cycle. While the reason(s) for this requirement remains unclear, it is known that unintegrated proviral DNA is epigenetically silenced. Here, we demonstrate that HIV-1 mutants lacking functional integrase can mount a robust, spreading infection in cells expressing the Tax transcription factor encoded by human T-cell leukemia virus 1. In these cells, HIV-1 forms episomal DNA circles, analogous to Hepatitis B virus covalently closed circular DNAs (cccDNAs), that are transcriptionally active and fully capable of supporting viral replication. This rescue correlates with the loss of inhibitory epigenetic marks, and the acquisition of activating marks, on histones bound to unintegrated HIV-1 DNA. Thus retroviral DNA integration may have evolved, at least in part, as a mechanism to avoid the epigenetic silencing of extrachromosomal viral DNA by host innate antiviral factors.SignificanceWhile retroviral DNA is synthesized normally after infection by integrase-deficient viruses, the resultant episomal DNA is then epigenetically silenced. Here, we show that expression of the Tax transcription factor encoded by a second human retrovirus, HTLV-1, prevents the epigenetic silencing of unintegrated HIV-1 DNA and instead induces the addition of activating epigenetic marks, and the recruitment of NF-kB/Rel proteins, to the HIV-1 LTR promoter. Moreover, in the presence of Tax, the HIV-1 DNA circles that form in the absence of integrase function are not only efficiently transcribed but also support a spreading, pathogenic IN- HIV-1 infection. Thus, retroviruses have the potential to replicate without integration, as is indeed seen with HBV.
Dynamic switching between intrinsic and extrinsic mode networks as demands change from passive to active processing
Authors: Riemer Frank , Grüner Renate , Beresniewicz Justyna , Kazimierczak Katarzyna , Ersland Lars , Hugdahl Kenneth 
Published: March 2020

AbstractWe here report on the relationship between default and extrinsic mode networks across alternating brief periods of rest and active task processing. We used three different visual tasks: mental rotation, working memory and mental arithmetic in a classic fMRI ON-OFF block design where task (ON) blocks alternated with equal periods of rest (OFF) blocks. By analysing data in two ways, using an ON-OFF contrast, we showed the existence of a generalized task-positive network, labelled the extrinsic mode network (EMN) which was anti-correlated with the default mode network (DMN) as processing demands shifted from rest to active processing. We then identified two key regions of interest (ROIs) in the SMA and Precuneus/PCC regions as hubs for the extrinsic and intrinsic networks, and extracted the time-course from these ROIs. The results showed a close to perfect correlations for the SMA and Precuneus/PCC time-courses for ON-respective OFF-blocks. We suggest the existence of two large-scale networks, an extrinsic mode network and an intrinsic mode network, respectively, which are up- and down-regulated as environmental demands change from active to passive processing.
Generation of excitatory and inhibitory neurons from common progenitors via Notch signaling in the cerebellum
Authors: Zhang Tingting , Liu Tengyuan , Mora Natalia , Guegan Justine , Bertrand Mathilde , Contreras Ximena , Hansen Andi H. , Streicher Carmen , Anderle Marica , Danda Natalia , Tiberi Luca , Hippenmeyer Simon , Hassan Bassem A. 
Published: March 2020

SUMMARYBrain neurons arise from relatively few progenitors capable of giving rise to an enormous diversity of neuronal types. Nonetheless, a cardinal feature of mammalian brain neurogenesis in both the cortex and the cerebellum is that excitatory neurons and inhibitory neurons derive from separate, spatially segregated, progenitors. Whether bi-potential progenitors with an intrinsic capacity to generate both excitatory and inhibitory lineages exist and how such a fate decision may be regulated is unknown. Using cerebellar development as a model, we discover that individual embryonic cerebellar progenitors give rise to both inhibitory and excitatory lineages. We find that gradations of Notch activity levels determine the fates of the progenitors and their daughters. Daughters with the highest levels of Notch activity retain the progenitor fate. Daughters with intermediate levels of Notch activity become fate restricted to generate inhibitory neurons, while daughters with very low levels of Notch signaling adopt the excitatory fate. Therefore, Notch mediated binary cell fate choice is a mechanism for regulating the ratio of excitatory to inhibitory neurons from common progenitors.Graphical summary
Assembly and Annotation of an Ashkenazi Human Reference Genome
Authors: Shumate Alaina , Zimin Aleksey V. , Sherman Rachel M. , Puiu Daniela , Wagner Justin M. , Olson Nathan D. , Pertea Mihaela , Salit Marc L. , Zook Justin M. , Salzberg Steven L. 
Published: March 2020

AbstractHere we describe the assembly and annotation of the genome of an Ashkenazi individual and the creation of a new, population-specific human reference genome. This genome is more contiguous and more complete than GRCh38, the latest version of the human reference genome, and is annotated with highly similar gene content. The Ashkenazi reference genome, Ash1, contains 2,973,118,650 nucleotides as compared to 2,937,639,212 in GRCh38. Annotation identified 20,157 protein-coding genes, of which 19,563 are >99% identical to their counterparts on GRCh38. Most of the remaining genes have small differences. 40 of the protein-coding genes in GRCh38 are missing from Ash1; however, all of these genes are members of multi-gene families for which Ash1 contains other copies. 11 genes appear on different chromosomes from their homologs in GRCh38. Alignment of DNA sequences from an unrelated Ashkenazi individual to Ash1 identified ~1 million fewer homozygous SNPs than alignment of those same sequences to the more-distant GRCh38 genome, illustrating one of the benefits of population-specific reference genomes.
Transition effect on aerodynamic performance of compressor profile
Authors: Szwaba Ryszard , Kaczyński Piotr , Doerffer Piotr 
Published: March 2020

Purpose
The purpose of this paper is to study experimentally the effect of transition and also the roughness height on the flow structure of the shock wave boundary layer interaction in the blades passage of a compressor cascade.

Design/methodology/approach
A model of a turbine compressor passage was designed and assembled in a transonic wind tunnel. In the experiment, the distributed roughness with different heights and locations was used to induce transition upstream of the shock wave.

Findings
Recommendation regarding the roughness parameters for the application depends on what is more important as goal, whether the reduction of losses or unsteadiness. In case if more important are the losses reduction, a good choice for the roughness location seems to be the one close to the shock wave position.

Research limitations/implications
The knowledge gained by this paper will enable the implementation of an effective laminar flow technology for engines in which the interaction of a laminar boundary layer with a shock wave takes place in the propulsion system and causes severe problems.

Originality/value
The paper focuses on the influence of the boundary layer transition induced by different roughness values and locations on aerodynamic performance of a compressor cascade. Very valuable results were obtained in the roughness application for the boundary layer transition control, demonstrating a positive effect in changing the nature of the interaction and also some negative influence in case of oversized roughness height, which cannot be found in the existing literature.
A new approach for improving work distribution in business processes supported by BPMS
Authors: Pereira José-Luís , Varajão João , Uahi Robbie 
Published: March 2020

PurposeThe purpose of this paper is regarding the execution of business processes by Business Process Management Systems (BPMS), during design-time modelers have to specify the potential performers of a work activity according to their organizational position or role. Once several workers may share the same role, at run-time all of them (indistinctively) can be assigned by BPMS to execute a work activity. However, distinct individuals have different personality traits and, for certain instances of work (requiring, for example, specific soft skills) some of them might perform better. A new approach to work distribution in business processes supported by BPMS, which takes into account the psychological characteristics of workers was proposed.Design/methodology/approachAs stated in Section 3 of the paper, in this work the Design Science Research (DSR) methodology, as proposed by Kuechler and Vaishnavi (2008) was used. All the five steps, from the “Awareness of problem” to the “Conclusion” were accomplished, being described in the paper.FindingsIt is demonstrated that, by using the proposed approach, BPMS might deliver work to people in a more effective way, by selecting those workers that seem to be more suitable to accomplish each particular piece of work, taking into account the characteristics of the work itself and the specific profiles of the workers eligible to execute it.Originality/valueBPMSs are responsible for the execution of business process models, by delivering work activities to suitable agents (human or artificial), which execute them. Addressing a gap in the BPM literature, this paper presents a new approach for improving work distribution in business processes supported by BPMS, enabling to assign (in run-time) the most suitable workers to perform specific work activities, grounded on the concept of psychological profile and taking into account technical, human and social aspects.
Critical success factors for the receptiveness of Islamic home financing in Malaysia
Authors: Amin Hanudin 
Published: March 2020

PurposeThe purpose of this study is to examine the critical success factors (CSFs) for the receptiveness of Islamic home financing in Malaysia.Design/methodology/approachA framework of the CSFs for the receptiveness of Islamic home financing is developed. The framework evaluates the effects of product type, competitive value proposition, Islamic debt collection policy, Islamic bankers' knowledge and maqasid al-Shariah compliance on the receptiveness. Data from 744 usable questionnaires are analysed to confirm the applicability of the framework in Islamic home financing context.FindingsThe results suggest that product type, competitive value proposition, Islamic debt collection policy, Islamic bankers' knowledge and maqasid al-Shariah compliance are significantly related to the receptiveness of Islamic home financing.Research limitations/implicationsTwo limitations are available for future studies. Firstly, the respondents of this study are limited to Malaysians, signifying further testing of the proposed model across different geographies is required to determine the generalisability of the model. Secondly, the contributions of the proposed framework are confined to a specific area of Islamic banking products. Thus, extending the framework to other banking products or conducting a comparative study between Islamic home financing and its conventional peer can improve its generalisability.Practical implicationsThe results obtained offer a fresh direction on how to market Islamic home financing products successfully, where the new CSFs are brought into play.Originality/valueThis study examines the new proposed CSFs for the receptiveness of Islamic home financing in Malaysia.
Empirical analysis on corporate environmental performance and environmental disclosure in an emerging market context
Authors: Acar Merve , Temiz Hüseyin 
Published: March 2020

PurposeThe purpose of this study is to investigate the association between environmental performance of firms and the level of voluntary environmental disclosure in emerging markets.Design/methodology/approachWe used tobit regression OLS andt-test methods to reveal the association between environmental performance and the level of voluntary environmental disclosure.FindingsWe find a significant positive association between the level of discretionary environmental disclosures and corporate environmental performance. The result is in line with the arguments of economics disclosure theory that argues environmentally good performers disclose more.Practical implicationsMany of the environmentally good firms in Turkey are also listed in the “BIST Sustainability Index,” and this situation can be the result of the relative power of external regulations. Accordingly, it can be suggested to increase the community and governmental pressures for environmental reporting but also gives importance to increase intrinsic motivations for companies to engage in disclosure practices.Originality/valueThis study shed light on relation between environmental performance and environmental disclosure in an emerging market context. Also, it is revisited that the relation between environmental performance and the level of environmental disclosure by testing two different predictions on the level of environmental disclosures.