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The celebrated Pólya’s conjecture (1954) in spectral geometry states that the eigenvalue counting functions of the Dirichlet and Neumann Laplacian on a bounded Euclidean domain can be estimated from above and below, respectively, by the leading term of Weyl’s asymptotics. Pólya’s conjecture is known to be true for domains which tile Euclidean space, and, in addition, for some special domains in higher dimensions. In this paper, we prove Pólya’s conjecture for the disk, making it the first non-tiling planar domain for which the conjecture is verified. We also confirm Pólya’s conjecture for arbitrary planar sectors, and, in the Dirichlet case, for balls of any dimension. Along the way, we develop the known links between the spectral problems in the disk and certain lattice counting problems. A key novel ingredient is the observation, made in recent work of the last named author, that the corresponding eigenvalue and lattice counting functions are related not only asymptotically, but in fact satisfy certain uniform bounds. Our proofs are purely analytic, except for a rigorous computer-assisted argument needed to cover the short interval of values of the spectral parameter in the case of the Neumann problem in the disk.

Photoreceptor transplantation is a potential future treatment for blindness caused by retinal degeneration. Photoreceptor transplantation restores visual responses in end-stage retinal degeneration, but has also been assessed in non-degenerate retinas. In the latter scenario, subretinal transplantation places donor cells beneath an intact host outer nuclear layer (ONL) containing host photoreceptors. Here we show that host cells are labelled with the donor marker through cytoplasmic transfer—94±4.1% of apparently well-integrated donor cells containing both donor and host markers. We detect the occurrence of Cre-Lox recombination between donor and host photoreceptors, and we confirm the findings through FISH analysis of X and Y chromosomes in sex-discordant transplants. We do not find evidence of nuclear fusion of donor and host cells. The artefactual appearance of integrated donor cells in host retinas following transplantation is most commonly due to material transfer from donor cells. Understanding this novel mechanism may provide alternate therapeutic strategies at earlier stages of retinal degeneration. Previous studies have used fluorescently labelled cells to demonstrate the incorporation of transplanted photoreceptor precursors into the mouse retina. Here, the authors show that fluorescent proteins are passed between the host and transplanted cells rather than migration of donor cells into the retina.

Mammoths provide a detailed example of species origins and dispersal, but understanding has been impeded by taxonomic confusion, especially in North America. The Columbian mammoth Mammuthus columbi was thought to have evolved in North America from a more primitive Eurasian immigrant. The earliest American mammoths (1.5 million years ago), however, resemble the advanced Eurasian M. trogontherii that crossed the Bering land bridge around that time, giving rise directly to M. columbi. Woolly mammoth M. primigenius later evolved in Beringia and spread into Europe and North America, leading to a diversity of morphologies as it encountered endemic M. trogontherii and M. columbi, respectively. In North America, this included intermediates (\"M. jeffersonii\"), suggesting introgression of M. primigenius with M. columbi. The lineage illustrates the dynamic interplay of local adaptation, dispersal, and gene flow in the evolution of a widely distributed species complex.

Invasive species are a major cause of biodiversity loss worldwide, but their impact on communities and the mechanisms driving those impacts are varied and not well understood. This study employs functional diversity metrics and guilds—suites of species with similar traits—to assess the influence of an invasive tree (Tamarix spp.) on riparian plant communities in the southwestern United States. We asked: (1) What traits define riparian plant guilds in this system? (2) How do the abundances of guilds vary along gradients of Tamarix cover and abiotic conditions? (3) How does the functional diversity of the plant community respond to the gradients of Tamarix cover and abiotic conditions? We found nine distinct guilds primarily defined by reproductive strategy, as well as growth form, height, seed weight, specific leaf area, drought and anaerobic tolerance. Guild abundance varied along a covarying gradient of local and regional environmental factors and Tamarix cover. Guilds relying on sexual reproduction, in particular, those producing many light seeds over a long period of time were more strongly associated with drier sites and higher Tamarix cover. Tamarix itself appeared to facilitate more shade-tolerant species with higher specific leaf areas than would be expected in resource-poor environments. Additionally, we found a high degree of specialization (low functional diversity) in the wettest, most flood-prone, lowest Tamarix cover sites as well as in the driest, most stable, highest Tamarix cover sites. These guilds can be used to anticipate plant community response to restoration efforts and in selecting appropriate species for revegetation.

Cells of the innate immune system produce cytokines and lipid mediators that strongly influence the outcome of mycobacterial infection. In the case of Mycobacterium tuberculosis, the lung is a critical site for this interaction. Here, we review current information on the role of the major innate cytokine pathways both in controlling initial infection as well as in promoting and maintaining adaptive T-cell responses that mediate host resistance or immunopathology. Understanding this important feature of the host–pathogen interaction can provide major insights into the mechanisms of virulence and can lead to new approaches for immunological intervention in tuberculosis and other mycobacterial diseases.

Abstract Chrozophora tinctoria (L.) A.Juss. is herbaceous, monecious annual plant used traditionally to cure gastrointestinal disorders. The present study was carried out to find the bioactive compounds by Gas Chromatography-Mass Spectrometry, the acetylcholinesterase inhibitory potential acute toxicity, and emetic activity present in the ethyl acetate fraction of Chrozophora tinctoria (EAFCT) and dichloromethane fraction of Chrozophora tinctoria (DCMFCT). The compounds detected in both fractions were mostly fatty acids, with about seven compounds in EAFCT and 10 in DCMFCT. These included pharmacologically active compounds such as imipramine, used to treat depression, or hexadecanoic acid methyl ester, an antioxidant, nematicide, pesticide, hypocholesterolemic, 9,12,15-Octadecatrienoic acid, ethyl ester, (Z,Z,Z)- is used as a cancer preventive, antiarthritic, antihistaminic, hepatoprotective, insectifuge, nematicide, Pentadecanoic acid, 14-methyl-, methyl ester have antifungal, antimicrobial and antioxidant activities, 10-Octadecanoic acid, methyl ester have the property to decrease blood cholesterol, Antioxidant and antimicrobial, 1-Eicosanol is used as an antibacterial, 1-Hexadecene has antibacterial, antioxidant, and antifungal activities. Both DCMFCT and EAFCT fractions inhibited acetylcholinesterase (AChE) activity with IC50 values of 10 µg and 130 µg, respectively. Both the fractions were found to be toxic in a dose-dependent manner, inducing emesis at 0.5g onward and lethargy and mortality from 3–5 g upwards. Both the fractions combined with distilled water showed highly emetic activity. The significant increase in the number of vomits was shown by EAFCT plus distilled water which are 7.50±1.29, 7.25±3.10, and 11.75±2.22 number of vomits at 1g, 2g, and 3g/kg concentration respectively, while DCMFCT plus distilled water showed 5.25±2.22, 7.50±2.52 and 10.25±2.22 number of vomits at 1g, 2, and 3g/kg correspondingly. The antiemetic standard drug metoclopramide has a higher impact against the emesis induced by both the fractions than dimenhydrinate. Metoclopramide decreases the number of vomits caused by EAFCT to 1.00±0.00, 2.00±0.00, 4.00±1.00 at 1g, 2, and 3g/kg sequentially, while dimenhydrinate decreases the number of vomits to 1.33±0.58, 2.33±1.15, 4.33±0.58 at 1g, 2, and 3g respectively. In the same way, Metochloprimide decreases the number of emesis caused by DcmCt from 5.25±2.22, 7.50±2.52, 10.25±2.22 to 1.33±0.58, 2.33±1.1, 4.33±0.58 at 1g, 2, and 3g/kg concentrations. The present study is the first documented report that scientifically validates the folkloric use of Chrozophora tinctoria as an emetic agent. Resumo Chrozophora tinctoria (L.) A.Juss. é uma planta anual herbácea, monoica, usada tradicionalmente para curar distúrbios gastrointestinais. O presente estudo foi realizado para encontrar os compostos bioativos por Cromatografia Gasosa-Espectrometria de Massa (GC-MS), a toxicidade aguda do potencial inibitório da acetilcolinesterase e a atividade emética presente na fração acetato de etila de Chrozophora tinctoria (EAFCT) e fração diclorometano de Chrozophora tinctoria (DCMFCT). Os compostos detectados em ambas as frações foram principalmente ácidos graxos, com cerca de sete compostos em EAFCT e 10 em DCMFCT. Estes incluíam compostos farmacologicamente ativos, como a imipramina, usada para tratar a depressão, ou éster metílico do ácido hexadecanoico, um antioxidante, nematicida, pesticida, hipocolesterolêmico, ácido 9,12,15-octadecatrienoico, éster etílico, (Z,Z,Z)- é usado como preventivo do câncer, antiartrítico, anti-histamínico, hepatoprotetor, inseticida, nematicida, ácido pentadecanoico, 14-metil-, éster metílico tem atividades antifúngicas, antimicrobianas e antioxidantes, ácido 10-octadecanoico, éster metílico tem a propriedade de diminuir o colesterol no sangue, antioxidante e antimicrobiano, o 1-Eicosanol é usado como antibacteriano, o 1-Hexadeceno possui atividades antibacteriana, antioxidante e antifúngica. Ambas as frações DCMFCT e EAFCT inibiram a atividade da acetilcolinesterase (AChE) com valores de IC50 de 10µg e 130µg, respectivamente. Ambas as frações foram consideradas tóxicas de maneira dose-dependente, induzindo vômitos a partir de 0,5g e letargia e mortalidade de 3g a 5g para cima. Ambas as frações combinadas com água destilada apresentaram atividade altamente emética. O aumento significativo no número de vômitos foi demonstrado pelo EAFCT mais água destilada, que são 7,50±1,29, 7,25±3,10 e 11,75±2,22 número de vômitos nas concentrações de 1g, 2g e 3g/kg, respectivamente, enquanto DCMFCT mais água destilada mostrou 5,25±2,22, 7,50±2,52 e 10,25±2,22 número de vômitos em 1g, 2g e 3g/kg, respectivamente. A droga padrão antiemética metoclopramida tem um impacto maior contra a emese induzida por ambas as frações do que o dimenidrinato. A metoclopramida diminui o número de vômitos causados por EAFCT para 1,00±0,00, 2,00±0,00, 4,00±1,00 a 1g, 2g e 3g/kg, sequencialmente, enquanto o dimenidrinato diminui o número de vômitos para 1,33±0,58, 2,33±1,15, 4,33± 0,58 a 1g, 2g e 3g, respectivamente. Da mesma forma, a metocloprimida diminui o número de vômitos causados por DcmCt de 5,25±2,22, 7,50±2,52, 10,25±2,22 para 1,33±0,58, 2,33±1,1, 4,33±0,58 nas concentrações de 1g, 2g e 3g/kg. O presente estudo é o primeiro relato documentado que valida cientificamente o uso folclórico de Chrozophora tinctoria como agente emético.

(1) Background: Zika virus (ZIKV), an arbo-flavivirus, is transmitted via Aeges aegyptii mosquitoes Following its major outbreaks in 2013, 2014 and 2016, WHO declared it a Public Health Emergency of International Concern. Symptoms of ZIKV infection include acute fever, conjunctivitis, headache, muscle & joint pain and malaise. Cases of its transmission also have been reported via perinatal, sexual and transfusion transmission. ZIKV pathologies include meningo-encephalitis and myelitis in the central nervous system (CNS) and Guillain-Barré syndrome and acute transient polyneuritis in the peripheral nervous system (PNS). Drugs like azithromycin have been tested as inhibitors of ZIKV infection but no vaccines or treatments are currently available. Astrocytes are the most abundant cells in the CNS and among the first cells in CNS infected by ZIKV; (2) Methods: We previously used SOMAScan proteomics to study ZIKV-infected astrocytic cells. Here, we use mass spectrometric analyses to further explain dysregulations in the cellular expression profile of glioblastoma astrocytoma U251 cells. We also knocked down (KD) some of the U251 cellular proteins using siRNAs and observed the impact on ZIKV replication and infectivity; (3) Results & Conclusions: The top ZIKV dysregulated cellular networks were antimicrobial response, cell death, and energy production while top dysregulated functions were antigen presentation, viral replication and cytopathic impact. Th1 and interferon signaling pathways were among the top dysregulated canonical pathways. siRNA-mediated KD of HLA-A, IGFBP5, PSMA2 and HSPA5 increased ZIKV titers and protein synthesis, indicating they are ZIKV restriction factors. ZIKV infection also restored HLA-A expression in HLA-A KD cells by 48 h post-infection, suggesting interactions between this gene product and ZIKV.

The development of Th1 lymphocytes is essential for cell-mediated immunity and resistance against intracellular pathogens. However, if left unregulated, the same response can cause serious damage to host tissues and lead to mortality. A number of different paracrine regulatory mechanisms involving distinct myeloid and lymphoid subpopulations have been implicated in controlling excessive secretion of inflammatory cytokines by Th1 cells. Much of this work has focused on interleukin (IL)-10, a cytokine with broad anti-inflammatory properties, one of which is to counteract the function of Th1 lymphocytes. While studying the role of IL-10 in regulating immunopathology during infection with the intracellular parasite Toxoplasma gondii, we discovered that the host-protective IL-10 derives in an autocrine manner from conventional interferon-γ (IFN-γ)-producing T-bet+ Foxp3neg Th1 cells. In the following review, we will discuss these findings that support the general concept that production of IL-10 is an important self-regulatory function of CD4+ T lymphocytes.