91 research outputs found
A contextual usage control model
Model praćenja uporabe (UCON) je najnovije veliko poboljšanje tradicionalnih modela za praćenje pristupa. On omogućava promjenljivost atributa subjekta i objekta i kontinuitet praćenja uporabe. Međutim, taj model može zabraniti pristup zbog promjena u okolini čak i ako su zadovoljeni zahtjevi autorizacije i obveze te tako korisnicima stvoriti prekide. Predložen je kontekstualni UCON (CUC) kako bi se prevladala ta osnovna slabost UCONa. U CUC-u se uvodi kontekst kao zamjena za komponentu uvjeta u UCON-u. Dodaje se modul upravljanja za manipuliranje atributima subjekta, objekta i konteksta. CUC izravno kombinira module praćenja i upravljanja i može dinamički prilagođavati promjene u kontekstu te je uistinu baziran na atributima. Primijenjen je algebarski pristup za opis sintakse i semantike CUCa.The usage control model (UCON) is the latest major enhancement of traditional access control models. It enables subject and object attributes mutability and usage control continuity. However, with the model access permission may be denied as a result of the environmental changes even though the authorization and obligation requirements are met, thus causing disruptions to users. Contextual UCON (CUC) was proposed to overcome this major weakness of UCON. In CUC context was introduced to replace the conditions component in UCON. And management module was added to manipulate the subject and object and context attributes. CUC seamlessly combines control and management modules and has the ability to dynamically adapt the changes in context, and is truly attribute-based. An algebra approach was employed to describe CUC syntax and semantics formally
Strategies Developed by Toxoplasma gondii to Survive in the Host
One of the most successful intracellular parasites, Toxoplasma gondii has developed several strategies to avoid destruction by the host. These include approaches such as rapid and efficient cell invasion to avoid phagocytic engulfment, negative regulation of the canonical CD40-CD40L-mediated autophagy pathway, impairment of the noncanonical IFN-γ-dependent autophagy pathway, and modulation of host cell survival and death to obtain lifelong parasite survival. Different virulent strains have even evolved different ways to cope with and evade destruction by the host. This review aims to illustrate every aspect of the game between the host and Toxoplasma during the process of infection. A better understanding of all aspects of the battle between Toxoplasma and its hosts will be useful for the development of better strategies and drugs to control the parasite
A contextual usage control model
Model praćenja uporabe (UCON) je najnovije veliko poboljšanje tradicionalnih modela za praćenje pristupa. On omogućava promjenljivost atributa subjekta i objekta i kontinuitet praćenja uporabe. Međutim, taj model može zabraniti pristup zbog promjena u okolini čak i ako su zadovoljeni zahtjevi autorizacije i obveze te tako korisnicima stvoriti prekide. Predložen je kontekstualni UCON (CUC) kako bi se prevladala ta osnovna slabost UCONa. U CUC-u se uvodi kontekst kao zamjena za komponentu uvjeta u UCON-u. Dodaje se modul upravljanja za manipuliranje atributima subjekta, objekta i konteksta. CUC izravno kombinira module praćenja i upravljanja i može dinamički prilagođavati promjene u kontekstu te je uistinu baziran na atributima. Primijenjen je algebarski pristup za opis sintakse i semantike CUCa.The usage control model (UCON) is the latest major enhancement of traditional access control models. It enables subject and object attributes mutability and usage control continuity. However, with the model access permission may be denied as a result of the environmental changes even though the authorization and obligation requirements are met, thus causing disruptions to users. Contextual UCON (CUC) was proposed to overcome this major weakness of UCON. In CUC context was introduced to replace the conditions component in UCON. And management module was added to manipulate the subject and object and context attributes. CUC seamlessly combines control and management modules and has the ability to dynamically adapt the changes in context, and is truly attribute-based. An algebra approach was employed to describe CUC syntax and semantics formally
Bringing class back in: class consciousness and solidarity among Chinese migrant workers in Italy and the UK
The growing literature on international migration has a tendency to emphasize homogenous elements such as shared ethnic background, social network and cultural similarities in shaping immigrants' identity. We argue that this underestimates the differences (and sometimes conflicts) of interests between ethnic employers and migrant workers and that class needs to be brought back into the studies of ethnic relationship. Based upon findings from a series of fieldwork in Veneto, Italy and East Midlands, UK, this article contends that class consciousness has co-existed, sometimes uneasily, alongside co-ethnic and cultural relationships among Chinese migrant workers and has played an important part in the making of new Chinese communities. By analysing the perspectives of Chinese migrant workers and their relationship with co-ethnic entrepreneurs, this article illustrates complex factors behind the formation, diffusion and development of class consciousness among Chinese migrant workers
A global view of porcine transcriptome in three tissues from a full-sib pair with extreme phenotypes in growth and fat deposition by paired-end RNA sequencing
<p>Abstract</p> <p>Background</p> <p>Elucidation of the pig transcriptome is essential for interpreting functional elements of the genome and understanding the genetic architecture of complex traits such as fat deposition, metabolism and growth.</p> <p>Results</p> <p>Here we used massive parallel high-throughput RNA sequencing to generate a high-resolution map of the porcine mRNA and miRNA transcriptome in liver, longissimus dorsi and abdominal fat from two full-sib F<sub>2 </sub>hybrid pigs with segregated phenotypes on growth, blood physiological and biochemical parameters, and fat deposition. We obtained 8,508,418-10,219,332 uniquely mapped reads that covered 78.0% of the current annotated transcripts and identified 48,045-122,931 novel transcript fragments, which constituted 17,085-29,499 novel transcriptional active regions in six tested samples. We found that about 18.8% of the annotated genes showed alternative splicing patterns, and alternative 3' splicing is the most common type of alternative splicing events in pigs. Cross-tissue comparison revealed that many transcriptional events are tissue-differential and related to important biological functions in their corresponding tissues. We also detected a total of 164 potential novel miRNAs, most of which were tissue-specifically identified. Integrated analysis of genome-wide association study and differential gene expression revealed interesting candidate genes for complex traits, such as <it>IGF2, CYP1A1, CKM </it>and <it>CES1 </it>for heart weight, hemoglobin, pork pH value and serum cholesterol, respectively.</p> <p>Conclusions</p> <p>This study provides a global view of the complexity of the pig transcriptome, and gives an extensive new knowledge about alternative splicing, gene boundaries and miRNAs in pigs. Integrated analysis of genome wide association study and differential gene expression allows us to find important candidate genes for porcine complex traits.</p
Balancing Selection of a Frame-Shift Mutation in the MRC2 Gene Accounts for the Outbreak of the Crooked Tail Syndrome in Belgian Blue Cattle
We herein describe the positional identification of a 2-bp deletion in the open reading frame of the MRC2 receptor causing the recessive Crooked Tail Syndrome in cattle. The resulting frame-shift reveals a premature stop codon that causes nonsense-mediated decay of the mutant messenger RNA, and the virtual absence of functional Endo180 protein in affected animals. Cases exhibit skeletal anomalies thought to result from impaired extracellular matrix remodeling during ossification, and as of yet unexplained muscular symptoms. We demonstrate that carrier status is very significantly associated with desired characteristics in the general population, including enhanced muscular development, and that the resulting heterozygote advantage caused a selective sweep which explains the unexpectedly high frequency (25%) of carriers in the Belgian Blue Cattle Breed
Novel virus-like nanoparticle vaccine effectively protects animal model from SARS-CoV-2 infection
The key to battling the COVID-19 pandemic and its potential aftermath is to develop a variety
of vaccines that are efficacious and safe, elicit lasting immunity, and cover a range of
SARS-CoV-2 variants. Recombinant viral receptor-binding domains (RBDs) are safe vaccine
candidates but often have limited efficacy due to the lack of virus-like immunogen display
pattern. Here we have developed a novel virus-like nanoparticle (VLP) vaccine that
displays 120 copies of SARS-CoV-2 RBD on its surface. This VLP-RBD vaccine mimics
virus-based vaccines in immunogen display, which boosts its efficacy, while maintaining the
safety of protein-based subunit vaccines. Compared to the RBD vaccine, the VLP-RBD vaccine
induced five times more neutralizing antibodies in mice that efficiently blocked SARSCoV-
2 from attaching to its host receptor and potently neutralized the cell entry of variant
SARS-CoV-2 strains, SARS-CoV-1, and SARS-CoV-1-related bat coronavirus. These neutralizing
immune responses induced by the VLP-RBD vaccine did not wane during the twomonth
study period. Furthermore, the VLP-RBD vaccine effectively protected mice from
SARS-CoV-2 challenge, dramatically reducing the development of clinical signs and pathological
changes in immunized mice. The VLP-RBD vaccine provides one potentially effective
solution to controlling the spread of SARS-CoV-2
The water lily genome and the early evolution of flowering plants
Water lilies belong to the angiosperm order Nymphaeales. Amborellales,
Nymphaeales and Austrobaileyales together form the so-called ANA-grade of
angiosperms, which are extant representatives of lineages that diverged the earliest
from the lineage leading to the extant mesangiosperms1–3. Here we report the
409-megabase genome sequence of the blue-petal water lily (Nymphaea colorata).
Our phylogenomic analyses support Amborellales and Nymphaeales as successive
sister lineages to all other extant angiosperms. The N. colorata genome and 19 other
water lily transcriptomes reveal a Nymphaealean whole-genome duplication event,
which is shared by Nymphaeaceae and possibly Cabombaceae. Among the genes
retained from this whole-genome duplication are homologues of genes that regulate
flowering transition and flower development. The broad expression of homologues of
floral ABCE genes in N. colorata might support a similarly broadly active ancestral
ABCE model of floral organ determination in early angiosperms. Water lilies have
evolved attractive floral scents and colours, which are features shared with
mesangiosperms, and we identified their putative biosynthetic genes in N. colorata.
The chemical compounds and biosynthetic genes behind floral scents suggest that
they have evolved in parallel to those in mesangiosperms. Because of its unique
phylogenetic position, the N. colorata genome sheds light on the early evolution of
angiosperms.Supplementary Tables: This file contains Supplementary Tables 1-21.National Natural Science Foundation of China, the open funds of the State Key Laboratory of Crop Genetics and Germplasm Enhancement (ZW201909) and State Key Laboratory of Tree Genetics and Breeding, the Fujian provincial government in China, the European Union Seventh Framework Programme (FP7/2007-2013) under European Research Council Advanced Grant Agreement and the Special Research Fund of Ghent University.http://www.nature.com/naturecommunicationsam2021BiochemistryGeneticsMicrobiology and Plant Patholog
A mechanistic study of Toxoplasma gondii ROP18 inhibiting differentiation of C17.2 neural stem cells
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