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We present the first experimental search for the rare charm decay D0→π0ν¯ν. It is based on an e+e− collision sample consisting of 10.6×10^6 pairs of D0¯D0 mesons collected by the BESIII detector at √s=3.773 GeV, corresponding to an integrated luminosity of 2.93 fb^−1. A data-driven method is used to ensure the reliability of the background modeling. No significant D0→π0ν¯ν signal is observed in data and an upper limit of the branching fraction is set to be 2.1×10^-4 at the 90% confidence level. This is the first experimental constraint on charmed-hadron decays into dineutrino final states.
The Born cross sections of the e+e− → D*+D*− and e+e− → D*+D− processes are measured using e+e− collision data collected with the BESIII experiment at center-of-mass energies from 4.085 to 4.600 GeV, corresponding to an integrated luminosity of 15.7 fb−1. The results are consistent with and more precise than the previous measurements by the Belle, Babar and CLEO collaborations. The measurements are essential for understanding the nature of vector charmonium and charmonium-like states.
In search for practical silvicultural management tools to identify alternative tree species for predicted Central European climate conditions, a cross-species survey with five evergreen, semi-evergreen, and deciduous Quercus taxa with contrasting morphological leaf traits was performed. Fast chlorophyll fluorescence induction of PSII and relative leaf chlorophyll contents were performed to assess the overall plant vitality at any point in time during two complete vegetation periods in consecutive years (2012 and 2013). Maximum photochemical efficiency of PSII and the performance index on absorption base showed a very conservative relationship to each other and a similar intra-annual progress in all deciduous species, but with a different speed of increase and decrease during leaf development and senescence and thus a different length of vegetation period. The intra-annual variability of OJIP and chlorophyll content parameters is considered with respect to the practicability of measurements in the field for management purposes.
The effect of the extreme summer drought and heatwave 2018 in Central Europe on wood properties of oaks at four sandy valley river sites (Quercus robur L.) and one south-exposed schist slope (Qu. petraea (Matt.) Liebl.) in the middle Rhine and lower Main valley were studied and compared to well-watered trees from a riparian stand. While properties of the 2018 tree rings mostly resembled those of the previous (wet) year, significant decreases in Δ13C, wood density and ring width occurred in 2019 at most drought-prone sites. In the sandy sites, ring widths correlated with previous-year precipitation from June to August over a 20-year period. In organs formed in 2018, in general, decreasing Δ13C values were obtained in the order leaves, twigs, wood and acorns, with the values from acorns often resembling those from 2019-year rings. The observed changes indicated an increased intrinsic water use efficiency and lack of starch reserve formation during the unprecedented hot and dry summer 2018. Qu. petraea revealed quite different values from Qu. robur (lower Δ13C, wider and denser year rings), but qualitatively showed the same reaction to the drought in 2018, except for an enhanced formation of tyloses in recent-year tree rings.
Oaks may contribute to the stabilization of European forests under climate change. We utilized two common gardens established in contrasting growth regimes, in Greece (Olympiada) and Germany (Schwanheim), to compare the diurnal photosynthetic performance of a Greek and an Italian provenance of two Mediterranean oaks (Quercus pubescens and Q. frainetto) during the 2019 growing season. Although the higher radiation in the southern common garden led to a strong midday depression of chlorophyll a fluorescence parameters (maximum quantum efficiency of PSII, performance index on absorption basis), comparable light-saturated net photosynthetic rates were achieved in both study areas. Moreover, both species and provenances exhibited analogous responses. Q. pubescens had enhanced chlorophyll a fluorescence traits but similar photosynthetic rates compared to Q. frainetto, whereas the provenances did not differ. These findings indicate the high photosynthetic efficiency of both oaks under the current climate in Central Europe and their suitability for assisted migration schemes.
Young trees of deciduous Quercus robur and Q. petraea and evergreen Q. ilex were grown together in a competition lysimeter experiment to assess i) – whether the observed growth differences between evergreen Q. ilex and the deciduous Q. robur and Q. petraea on sandy soil in the field and ii) – whether the different natural distribution of Q. robur and Q. petraea could be attributed to physiological differences between the species under experimental drought stress (DS). Half of the plants were subjected to long-term DS in two consecutive years and monitored for physiological and growth parameters. In the first year, water withholding for more than three months did not lead to significant drought stress, probably because of a sufficient residual water volume in the lysimeter for the relatively small plants. However, in the second year, 2018, which was warmer, the bigger plants now competed for the residual water and clear drought stress symptoms developed for more than two months in all trees in the DS lysimeter basin. Growth was only moderately (and mostly not significantly) affected by the DS in the second year, except for a smaller total leaf area in DS Q. ilex as compared to DS Q. robur and Q. petraea and smaller root collar diameter in DS Q. ilex compared to DS Q. robur. Under DS, the deciduous species revealed significant decreases in ΔVIP, indicating a negative effect on electron transport through PS I. Pn, PIabs and water relations parameters (ΨPD and LWC) all decreased to various extents under DS in all three species, leading to clear separation of the deciduous from the evergreen species by PCA. However, PCA did not separate the two deciduous species from each other. It is concluded that longer root growth in the two deciduous species as compared to Q. ilex ameliorates DS effects in Q. robur and Q. petraea and may be the key to understand the better performance of deciduous oaks on sandy soil in the field.
Tree water relations of mature oaks in southwest Germany under extreme drought stress in summer 2018
(2021)
Mature oak stands of different tree height at four sandy valley river sites (Quercus robur) and one south-exposed schist slope (Qu. petraea) in the middle Rhine and lower Main valley were studied from early summer 2017 (normal wet year) until the end of 2018 (extremely hot and dry year). Tree water relations (ΨPD, RWC, sap flow rates) were monitored together with soil water relations, LAI and leaf chl content. In two sandy sites with presumed continuous capillary water access from the groundwater aquifer, sap flow rates of the large trees (30 m) and estimated canopy conductance decreased to about 50% of the maximum value in the course of summer 2018, but recovered in autumn. At two other sites, with smaller trees (14–24 m) and presumed interrupted capillary water access during mid-summer 2018, sap flow rates and canopy conductance broke down completely and trees shed a large proportion of leaves in summer. In one of these sites, ΨPD decreased (reversibly) to -4 MPa, one of the lowest values reported in the literature for central Europe, and tree damage resulted not only in extreme leaf shedding, but also in susceptibility to uprooting (in 2 out of 5 measured trees) by thunderstorm gusts in autumn 2018. At the schist slope site, where oaks reached the lowest height and stand density of all sites, sap flow rates remained similar to the values found at the presumed capillary-water supplied sandy sites, indicating access to rock fissure water even at the peak of the drought period. Our findings corroborate the prediction from vegetation modelling that several Qu. robur stands in the Rhine-Main valleys will be prone to severe forest dieback in the forthcoming decades.
Philadelphia-like B-cell precursor acute lymphoblastic leukemia (Ph-like ALL) is characterized by distinct genetic alterations and inferior prognosis in children and younger adults. The purpose of this study was a genetic and clinical characterization of Ph-like ALL in adults. Twenty-six (13%) of 207 adult patients (median age: 42 years) with B-cell precursor ALL (BCP-ALL) were classified as having Ph-like ALL using gene expression profiling. The frequency of Ph-like ALL was 27% among 95 BCP-ALL patients negative for BCR-ABL1 and KMT2A-rearrangements. IGH-CRLF2 rearrangements (6/16; P=0.002) and mutations in JAK2 (7/16; P<0.001) were found exclusively in the Ph-like ALL subgroup. Clinical and outcome analyses were restricted to patients treated in German Multicenter Study Group for Adult ALL (GMALL) trials 06/99 and 07/03 (n=107). The complete remission rate was 100% among both Ph-like ALL patients (n=19) and the “remaining BCP-ALL” cases (n=40), i.e. patients negative for BCR-ABL1 and KMT2A-rearrangements and the Ph-like subtype. Significantly fewer Ph-like ALL patients reached molecular complete remission (33% versus 79%; P=0.02) and had a lower probability of continuous complete remission (26% versus 60%; P=0.03) and overall survival (22% versus 64%; P=0.006) at 5 years compared to the remaining BCP-ALL patients. The profile of genetic lesions in adults with Ph-like ALL, including older adults, resembles that of pediatric Ph-like ALL and differs from the profile in the remaining BCP-ALL. Our study is the first to demonstrate that Ph-like ALL is associated with inferior outcomes in intensively treated older adult patients. Ph-like adult ALL should be recognized as a distinct, high-risk entity and further research on improved diagnostic and therapeutic approaches is needed.
Climate change imposes severe stress on European forests, with forest degradation already visible in several parts of Europe. Thus adaptation of forestry applications in Mediterranean areas and central Europe is necessary. Proactive forestry management may include the planting of Mediter- ranean oak species in oak-bearing Central European regions. Five replicate common gardens of Greek and Italian provenances of Quercus ilex, Q. pubescens and Q. frainetto seedlings (210 each per plantation) were established in Central Italy, NE Greece (two) and Southern Germany (two, including Q. robur) to assess their performance under different climate conditions. Climate and soil data of the plantation sites are given and seedling establishment was monitored for survival and morphological parameters. After 3 years (2019) survival rates were satisfactory in the German and Italian sites, whereas the Greek sites exerted extremely harsh conditions for the seedlings, including extreme frost and drought events. In Germany, seedlings suffered extreme heat and drought periods in 2018 and 2019 but responded well. Provenances were ranked for each country for their performance after plan- tation. In Greece and Italy, Q. pubescens was the best performing species. In Germany, Q. pubescens and Q. robur performed best. We suggest that Greek or Italian provenances of Q. pubescens may be effectively used for future forestation purposes in Central Europe. For the establishment of Quercus plantations in Northern Greece, irrigation appears to be a crucial factor in seedling establishment.
The adaptive response of Sorghum bicolor landraces from Egypt to drought stress and following recovery was analyzed using two-dimensional difference gel electrophoresis, 2D-DIGE. Physiological measurements and proteome alterations of accession number 11434, drought tolerant, and accession number 11431, drought sensitive, were compared to their relative control values after drought stress and following recovery. Differentially expressed proteins were analysed by Matrix assisted laser desorption ionisation time-of-flight mass spectrometry, MALDI-TOF-MS. Alterations in protein contents related to the energy balance, metabolism (sensu Mewes et al. 1997), and chaperons were the most apparent features to elucidate the differences between the drought tolerant and sensitive accessions. Further alterations in the levels of proteins related to transcription and protein synthesis are discussed.
