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BackgroundClinical recurrence of COVID-19 in convalescent patients has been reported, which immune mechanisms have not been thoroughly investigated. Presence of neutralizing antibodies suggests other types of immune response are involved.MethodsWe assessed the innate type I/III IFN response, T cell responses to SARS-CoV-2 with IFNγ ELISPOT, binding and neutralizing antibody assays, in two monozygotic twin pairs with one COVID-19 recurrence case.ResultsIn pair 1, four months after a first mild episode of infection for both siblings, one displayed severe clinical recurrence of COVID-19. Twin pair 2 of siblings underwent non-recurring asymptomatic infection. All fours individuals presented similar overall responses, except for remarkably difference found in specific cellular responses. Recurring sibling presented a reduced number of recognized T cell epitopes as compared to the other three including her non-recurring sibling.ConclusionsOur results suggest that an effective SARS-CoV-2-specific T cell immune response is key for complete viral control and avoidance of clinical recurrence of COVID-19. Besides, adaptive immunity can be distinct in MZ twins. Given the rising concern about SARS-CoV-2 variants that evade neutralizing antibodies elicited by vaccination or infection, our study stresses the importance of T cell responses in protection against recurrence/reinfection.Key pointsImmune parameters leading to COVID-19 recurrence/reinfection are incompletely understood. A COVID-19 recurrence case in a monozygotic twin pair is described with an intact antibody and innate type I/III Interferon response and drastically reduced number of recognized SARS-CoV-2 T cell epitopes.

In the era of climate change, rice (Oryza sativa L.) production is increasingly affected by the rising frequency and severity of various abiotic stresses such as flood and drought. In some cases, 100 % yield loss can be attributed solely to these stresses. Hence, there is an urgent need to develop climate-smart rice that is more resilient to abiotic stresses. As the development and dissemination of climate-smart rice varieties entail costs, this article examines the net economic benefits of developing and disseminating successful drought-tolerant rice in South Asia where rice area prone to drought far outweighs area with other abiotic stresses. Drought causes major rice yield losses not only in South Asia but also in other parts of Asia and Africa. Using the ORYZA2000 (ORYZA model series were developed at the International Rice Research Institute (IRRI) in the early 1990s in collaboration with Wageningen University and Research Centre (WUR) and 16 national agricultural research and extension systems in Asia. ORYZA2000 is an update and integration of earlier versions of the ORYZA model. More detailed documentation of ORYZA2000 can be found in ( http://books.irri.org/9712201716_content.pdf )) crop growth simulation model, we demonstrate that a successful drought-tolerant rice variety can provide yield gains in South Asia of a minimum of 1.71 % to a maximum of 8.96 % when there is no change in the climate and under different climate scenarios projected by Canadian General Circulation Models (CGCMs). Moreover, our economic analysis shows that the economic benefits from the successful development and dissemination of droughttolerant rice more than outweigh the research investments needed to develop a variety. Although the research, development, and dissemination of a climate-smart drought-tolerant rice variety in the South require USD 84 million, our economic model indicates that rice production will be higher by a minimum of 6 million tons worth USD 3.3 billion, and rice prices will be lower by a minimum of USD 72 per ton when a drought-tolerant variety is adopted in South Asia (as compared to the case without this new variety). This can lead to improved rice food security and better nutritional outcomes for the poor.

BackgroundSugarcane (Saccharum spp.) is highly polyploid and aneuploid. Modern cultivars are derived from hybridization betweenS. officinarumandS. spontaneum. This combination results in a genome exhibiting variable ploidy among different loci, a huge genome size (approximately 10 Gb) and a high content of repetitive regions. Gene expression mechanisms are poorly understood in these cultivars. An approach using genomic, transcriptomic and genetic mapping can improve our knowledge of the behavior of genetics in sugarcane.ResultsThe hypotheticalHP600and centromere protein C (CENP-C) genes from sugarcane were used to elucidate the allelic expression and genomic and genetic behavior of this complex polyploid. The genomically side-by-side genesHP600andCENP-Cwere found in two different homeologous chromosome groups with ploidies of eight and ten. The first region (Region01) was aSorghum bicolorortholog with all haplotypes ofHP600andCENP- Cexpressed, butHP600exhibited an unbalanced haplotype expression. The second region (Region02) was a scrambled sugarcane sequence formed from different noncollinear genes containing duplications ofHP600andCENP-C(paralogs). This duplication occurred before theSaccharumgenus formation and after the separation of sorghum and sugarcane, resulting in a nonexpressedHP600pseudogene and a recombined fusion version ofCENP-Cand orthologous gene Sobic.003G299500 with at least two chimerical gene haplotypes expressed. The genetic map construction supported the difficulty of mapping markers located in duplicated regions of complex polyploid genomes.ConclusionAll these findings describe a low synteny region in sugarcane, formed by events occurring in all members of theSaccharumgenus. Additionally, evidence of duplicated and truncate gene expression and the behavior of genetic markers in a duplicated region was found. Thus, we describe the complexity involved in sugarcane genetics and genomics and allelic dynamics, which can be useful for understanding the complex polyploid genome.

Plasminogen recruitment is a common strategy of pathogenic bacteria and results in a broad-spectrum surface-associated protease activity.Neisseria meningitidishas previously been shown to bind plasminogen. In this study, we show by several complementary approaches that endolase, DnaK, and peroxiredoxin, which are usually intracellular proteins, can also be located in the outer membrane and act as plasminogen receptors. Internal binding motifs, rather than C-terminal lysine residues, are responsible for plasminogen binding of theN. meningitidisreceptors. Recombinant receptor proteins inhibit plasminogen association withN. meningitidisin a concentration-dependent manner. Besides binding purified plasminogen,N. meningitidiscan also acquire plasminogen from human serum. Activation ofN. meningitidis-associated plasminogen by urokinase results in functional activity and allows the bacteria to degrade fibrinogen. Furthermore, plasmin bound toN. meningitidisis protected against inactivation by α2-antiplasmin.

The reconstruction of bones can tell a story about an individual lifestyle and the behaviours they practiced. Activities in an individual's life can produce specific skeletal markers that are related to repetitive activities associated with a particular physical activities or postures. Squatting is a good example of a behaviour producing skeletal markers on the bones, specifically, the neck of the talus (squatting facets) and its trochlear surface (trochlear extensions). Individual populations exhibit different incidences of these modifications that reflect their lifestyle and behaviour. The talus bone collected from Department of Anatomy of GSL Medical College, Rajamundry and Konaseema Institute of Medical Sciences and Research Foundation, Amalapuram were used to study modifications of talus bone with respect to habitual squatting in this region of East Godavari region of Andhra Pradesh. 90 bones (45 right and 45 left) were examined and analysis of the data indicates that majority of talus (62.2%) did not show any facet or extension; amongst the modifications, medial trochlear extension occurred most frequently (23.3%) followed by lateral squatting facet (6.7%), lateral trochlear extension (5.6%) and medial squatting facet (2.2%). There is a decline in the number of squatting facets when compared to the other studies; this difference may be because of study in different population or difference in life style.

Introduction: Co-processed excipients were prepared to improve the process ability and efficacy of commonly used excipients and to impart multi-functional qualities to the excipients and hence that the tablets with the desired attributes can be produced. In this study, acacia and calcium carbonate (CaCO3) were used to prepare a co-processing excipient suitable for the preparation of atorvastatin calcium tablets. Acacia is used as binder and CaCO3 as filler. CaCO3 also acts as alkalizer and thus suitable to improve the dissolution rate of pH dependent soluble drugs like atorvastatin. Materials and Methods: The tablets were prepared by direct compression method and the physical properties of tablets such as hardness, friability and dissolution profiles of tablets were evaluated. Acacia was used in the form of mucilage. Various ratios of the co-processing excipients were formulated by granulation technique and the blend properties were evaluated by their Hausner's ratio and Carr's index values. Based on the Kawakita plots, it was found that the formulation with 3% acacia mucilage (0.9 mg acacia and 26.6 mg of CaCO3) showed good fluidity and the formulations with 4% (1.27 mg of acacia and 26.23 mg of CaCO3) and 5% acacia mucilage (1.62 mg of acacia and 25.88 mg of CaCO3) showed more cohesiveness. The formulations include 1-5% of the acacia mucilage as the binding agent. Results: The granules of formulations with low percentage of acacia mucilage (1% and 2%) failed the test for friability. The granules of the formulations with pure acacia (F1) and pure CaCO3 (F2) showed passable flow properties. Conclusion: The formulation with 3% acacia mucilage (F3, 0.9 mg acacia and 26.6 mg of CaCO3) showed least dissolution time (