The COP9 SIGNALOSOME is required for postembryonic meristem maintenance in Arabidopsis thaliana

Cullin-RING E3 ligases (CRLs) regulate different aspects of plant development, and are activated by modification of their cullin subunit with the ubiquitin-like protein NEDD8 (NEural precursor cell expressed Developmentally Down-regulated 8) (neddylation) and deactivated by NEDD8 removal (deneddylation). The CONSTITUTIVELY PHOTOMORPHOGENIC9 (COP9) signalosome (CSN) acts as a molecular switch of CRLs activity by reverting their neddylation status, but its contribution to embryonic and early seedling development remains poorly characterized. Here, we analyzed the phenotypic defects of csn mutants and monitored the cullin deneddylation/neddylation ratio during embryonic and early seedling development. We show that while csn mutants can complete embryogenesis (albeit at a slower pace than wild type) and are able to germinate (albeit at a reduced rate), they progressively loose meristem activity upon germination, until they become unable to sustain growth. We also show that the majority of cullin proteins is progressively neddylated during the late stages of seed maturation and becomes deneddylated upon seed germination. This developmentally regulated shift in the cullin neddylation status is absent in csn mutants. We conclude that the CSN and its cullin deneddylation activity are required to sustain postembryonic meristem function in Arabidopsis

Scaling Development Finance for Our Common Future

The G-20 and the broader world community has committed to ambitious goals to close global infrastructure gaps, mitigate climate change, and advance the 2030 Agenda for development. We call on G20 leaders to task development finance institutions (DFIs) such as the development banks in member countries and the Multilateral Development Banks (MDBs) of which G-20 countries are members, to commit to scaling up resources by 25 percent, to calibrate new financing to international commitments to mitigate climate change and the 2030 agenda, and to work together as an inclusive system toward achieving those shared goals

COVID-19 and individual genetic susceptibility/receptivity: Role of ACE1/ACE2 genes, immunity, inflammation and coagulation. might the double x-chromosome in females be protective against SARS-COV-2 compared to the single x-chromosome in males?

In December 2019, a novel severe acute respiratory syndrome (SARS) from a new coronavirus (SARS-CoV-2) was recognized in the city of Wuhan, China. Rapidly, it became an epidemic in China and has now spread throughout the world reaching pandemic proportions. High mortality rates characterize SARS-CoV-2 disease (COVID-19), which mainly affects the elderly, causing unrestrained cytokines-storm and subsequent pulmonary shutdown, also suspected micro thromboembolism events. At the present time, no specific and dedicated treatments, nor approved vaccines, are available, though very promising data come from the use of anti-inflammatory, anti-malaria, and anti-coagulant drugs. In addition, it seems that males are more susceptible to SARS-CoV-2 than females, with males 65% more likely to die from the infection than females. Data from the World Health Organization (WHO) and Chinese scientists show that of all cases about 1.7% of women who contract the virus will die compared with 2.8% of men, and data from Hong Kong hospitals state that 32% of male and 15% of female COVID-19 patients required intensive care or died. On the other hand, the long-term fallout of coronavirus may be worse for women than for men due to social and psychosocial reasons. Regardless of sex-or gender-biased data obtained from WHO and those gathered from sometimes controversial scientific journals, some central points should be considered. Firstly, SARS-CoV-2 has a strong interaction with the human ACE2 receptor, which plays an essential role in cell entry together with transmembrane serine protease 2 (TMPRSS2); it is interesting to note that the ACE2 gene lays on the X-chromosome, thus allowing females to be potentially heterozygous and differently assorted compared to men who are definitely hemizygous. Secondly, the higher ACE2 expression rate in females, though controversial, might ascribe them the worst prognosis, in contrast with worldwide epidemiological data. Finally, several genes involved in inflammation are located on the X-chromosome, which also contains high number of immune-related genes responsible for innate and adaptive immune responses to infection. Other genes, out from the RAS-pathway, might directly or indirectly impact on the ACE1/ACE2 balance by influencing its main actors (e.g., ABO locus, SRY, SOX3, ADAM17). Unexpectedly, the higher levels of ACE2 or ACE1/ACE2 rebalancing might improve the outcome of COVID-19 in both sexes by reducing inflammation, thrombosis, and death. Moreover, X-heterozygous females might also activate a mosaic advantage and show more pronounced sex-related differences resulting in a sex dimorphism, further favoring them in counteracting the progression of the SARS-CoV-2 infection

Probing X-ray burst -- accretion disk interaction in low mass X-ray binaries through kilohertz quasiperiodic oscillations

The intense radiation flux of Type I X-ray bursts is expected to interact with the accretion flow around neutron stars. High frequency quasiperiodic oscillations (kHz QPOs), observed at frequencies matching orbital frequencies at tens of gravitational radii, offer a unique probe of the innermost disk regions. In this paper, we follow the lower kHz QPOs, in response to Type I X-ray bursts, in two prototypical QPO sources, namely 4U 1636-536 and 4U 1608-522, as observed by the Proportional Counter Array of the Rossi X-ray Timing Explorer. We have selected a sample of 15 bursts for which the kHz QPO frequency can be tracked on timescales commensurable with the burst durations (tens of seconds). We find evidence that the QPOs are affected for over ~200 s during one exceptionally long burst and ~100 s during two others (although at a less significant level), while the burst emission has already decayed to a level that would enable the pre-burst QPO to be detected. On the other hand, for most of our burst-kHz QPO sample, we show that the QPO is detected as soon as the statistics allow and in the best cases, we are able to set an upper limit of ~20 s on the recovery time of the QPO. This diversity of behavior cannot be related to differences in burst peak luminosity. We discuss these results in the framework of recent findings that accretion onto the neutron star may be enhanced during Type I X-ray bursts. The subsequent disk depletion could explain the disappearance of the QPO for ~100 s, as possibly observed in two events. However, alternative scenarios would have to be invoked for explaining the short recovery timescales inferred from most bursts. Clearly the combination of fast timing and spectral information of Type I X-ray bursts holds great potential in the study of the dynamics of the inner accretion flow around neutron stars.Comment: 8 pages, 9 figures, appears in Astronomy & Astrophysics, Volume 567, id.A80, published 07/201

Floristic Inventory of The Proposed Site for Tarsier Tourism Center in Villa Aurora, Bilar, Bohol, Philippines

The study assessed the present vegetation composition of the Proposed Site for the Tarsier Tourism Center (PTTC) at Villa Aurora, Bilar, Bohol and performed a comparative analysis with the existing Tarsier Sanctuary (TS) at Canapnapan, Corella, Bohol. The basis for comparison was the computed importance values, species richness, species dominance, and percent distribution of plants according to self-defined DBH classes. Results showed that both sites had very high species richness and evenness values. Common overstorey and understorey plant species found in both areas were katagpo (Psychotria sp.), sagimsim (Syzygium brevistylum [C. B. Rob]Merr.) and bagauak (Clerodendrum minahassae Teijsm. & Binn.). Apart from sagimsim (Syzygium brevistylum [C.B.Rob.] Merr.), selaginella (Selaginella cuppresina Lin.), and lunas (Lunasia amara Blanco) were also common in the ground vegetation of both areas. Percent distribution of trees according to self-defined DBH classes revealed that PTTC had 87.55% of the total recorded plants with DBH measurements of 20 cm. Percent distribution of trees on these DBH ranges (especially on DBH class >20 cm) indicated the presence of medium and large trees. The largest DBH measured in the PTTC was 70 cm while in TS was only 22 cm. The proposed 10-ha site in Villa Aurora, Bilar, is suited to be utilized as Tarsier Tourism Center. In case the proposed project is to be pursued, enclosure similar to what has been constructed in Canapnapan, Corella, Bohol, Philippines should also be established to prevent stray animals from predating the captive tarsiers.Keywords: floristic inventory, Philippine tarsier, Bohol, primate conservation, tourism. Inventarisasi flora dari Situs Usulan untuk Sentra Wisata Tarsier di Villa Aurora, Bilar, Bohol, FilipinaAbstractPenelitian ini ditujukan untuk melakukan penilaian komposisi vegetasi dari Usulan Lokasi Pusat Wisata Tarsius (ULPWT) di Villa Aurora, Bilar, Bohol dan melakukan analisis perbandingan antara Tarsier Sanctuary (TS) yang ada di Canapnapan, Corella, Bohol. Dasar perbandingan yang digunakan yaitu dengan menghitung nilai penting, kekayaan spesies, dominansi spesies, dan prosentase distribusi dari tumbuhan berdasarkan kelas diameter yang telah ditentukan. Hasil penelitian menunjukkan bahwa kedua tempat memiliki kekayaan spesies dan nilai evenness/ kemerataan yang sangat tinggi. Spesies tumbuhan yang umum ditemukan di overstorey dan understorey di kedua area adalah katagpo (Psychotria sp.), sagimsim (Syzygium brevistylum [C. B. Rob]Merr.), dan bagauak (Clerodendrum minahassae Teijsm. & Binn.). Selain itu, sagimsim (Syzygium brevistylum [C.B.Rob.] Merr.), selaginella (Selaginella cuppresina Lin.), dan lunas (Lunasia amara Blanco) juga umum ditemukan di lantai hutan di kedua tempat. Prosentase distribusi dari tumbuhan berdasarkan kelas diameter yang telah ditentukan menunjukkan bahwa ULPWT memiliki 87.55% dari keseluruhan tumbuhan yang tercatat dengan ukuran diameter 20 cm. Prosentase distribusi dari pohon pada kisaran ini (khususnya pada diameter >20 cm) menunjukkan adanya kehadiran pohon berukuran medium dan besar. Diameter terbesar yang terukur di ULPWT adalah 70 cm sementara di TS hanya sebesar 22 cm. Lokasi seluas 10 ha di Villa Aurora, Bilar, sesuai untuk digunakan sebagai Pusat Wisata Tarsius. Apabila akan didirikan, maka kandang yang dibangun diharapkan mirip dengan yang telah dibangun di Canapnapan, Corella, Bohol, Pilipina, agar mencegah pemangsaan oleh satwa yang lepas.

X-ray Reflection and An Exceptionally Long Thermonuclear Helium Burst from IGR J17062-6143

Thermonuclear X-ray bursts from accreting neutron stars power brief but strong irradiation of their surroundings, providing a unique way to study accretion physics. We analyze MAXI/Gas Slit Camera and Swift/XRT spectra of a day-long flash observed from IGR J17062-6143 in 2015. It is a rare case of recurring bursts at a low accretion luminosity of 0.15% Eddington. Spectra from MAXI, Chandra, and NuSTAR observations taken between the 2015 burst and the previous one in 2012 are used to determine the accretion column. We find it to be consistent with the burst ignition column of 5 × 10^(10) g cm^(−2), which indicates that it is likely powered by burning in a deep helium layer. The burst flux is observed for over a day, and decays as a straight power law: F ∝ t^(-1.15). The burst and persistent spectra are well described by thermal emission from the neutron star, Comptonization of this emission in a hot optically thin medium surrounding the star, and reflection off the photoionized accretion disk. At the burst peak, the Comptonized component disappears, when the burst may dissipate the Comptonizing gas, and it returns in the burst tail. The reflection signal suggests that the inner disk is truncated at ~102 gravitational radii before the burst, but may move closer to the star during the burst. At the end of the burst, the flux drops below the burst cooling trend for 2 days, before returning to the pre-burst level