In terrestrial ecosystems, plant species and diverse root‐associated fungi form complex networks of host–symbiont associations. Recent studies have revealed that structures of those below‐ground ...plant–fungus networks differ between arbuscular mycorrhizal and ectomycorrhizal symbioses. Nonetheless, we still remain ignorant of how ericaceous plant species, which dominate arctic and alpine tundra, constitute networks with their root‐associated fungi. Based on a high‐throughput DNA sequencing data set, we characterized the statistical properties of a network involving 16 ericaceous plant species and more than 500 fungal taxa in the alpine–subalpine region of Mt. Tateyama, central Japan. While all the 16 ericaceous species were associated mainly with fungi in the order Helotiales, they varied remarkably in association with fungi in other orders such as Sebacinales, Atheliales, Agaricales, Russulales and Thelephorales. The ericaceous plant–fungus network was characterized by high symbiont/host preferences. Moreover, the network had a characteristic structure called ‘anti‐nestedness’, which has been previously reported in ectomycorrhizal plant–fungus networks. The results lead to the hypothesis that ericaceous plants in harsh environments can host unexpectedly diverse root‐associated fungal taxa, constituting networks whose structures are similar to those of previously reported ectomycorrhizal networks but not to those of arbuscular mycorrhizal ones.
1. The constraint on vertical water transport is considered an important factor limiting height growth and maximum attainable height of trees. Here, we show evidence of foliar water storage as a ...mechanism that could partially compensate for this constraint in Sequoia sempervirens, the tallest species. 2. We measured hydraulic and morpho-anatomical characteristics of foliated shoots of tall S. sempervirens trees near the wet, northern and dry, southern limits of its geographic distribution in California, USA. 3. The ability to store water (hydraulic capacitance) and saturated water content (leaf succulence) of foliage both increased with height and light availability, maintaining tolerance of leaves to water stress (bulk-leaf water potential at turgor loss) constant relative to height. 4. Transverse-sectional area of water-storing, transfusion tissue in leaves increased with height, while the area of xylem tissue decreased, indicating increasing allocation to water storage and decreasing reliance on water transport from roots. 5. Treetop leaves of S. sempervirens absorb moisture via leaf surfaces and have potential to store more than five times the daily transpirational demand. Thus, foliar water storage may be an important adaptation that helps maintain physiological function of treetop leaves and hydraulic status of the crown, allowing this species to partially compensate for hydraulic constraints and sustain turgor for both photosynthesis and height growth.
Gemcitabine plus cisplatin (GC) is the standard treatment of advanced biliary tract cancer (BTC); however, it causes nausea, vomiting, and anorexia, and requires hydration. Gemcitabine plus S-1 (GS) ...reportedly has equal to, or better, efficacy and an acceptable toxicity profile. We aimed to confirm the non-inferiority of GS to GC for patients with advanced/recurrent BTC in terms of overall survival (OS).
We undertook a phase III randomized trial in 33 institutions in Japan. Eligibility criteria included chemotherapy-naïve patients with recurrent or unresectable BTC, an Eastern Cooperative Oncology Group Performance Status of 0−1, and adequate organ function. The calculated sample size was 350 with a one-sided α of 5%, a power of 80%, and non-inferiority margin hazard ratio (HR) of 1.155. The primary end point was OS, while the secondary end points included progression-free survival (PFS), response rate (RR), adverse events (AEs), and clinically significant AEs defined as grade ≥2 fatigue, anorexia, nausea, vomiting, oral mucositis, or diarrhea.
Between May 2013 and March 2016, 354 patients were enrolled. GS was found to be non-inferior to GC median OS: 13.4months with GC and 15.1months with GS, HR, 0.945; 90% confidence interval (CI), 0.78–1.15; P=0.046 for non-inferiority. The median PFS was 5.8months with GC and 6.8months with GS (HR 0.86; 95% CI 0.70–1.07). The RR was 32.4% with GC and 29.8% with GS. Both treatments were generally well-tolerated. Clinically significant AEs were observed in 35.1% of patients in the GC arm and 29.9% in the GS arm.
GS, which does not require hydration, should be considered a new, convenient standard of care option for patients with advanced/recurrent BTC.
This trial has been registered with the UMIN Clinical Trials Registry (http://www.umin.ac.jp/ctr/index.htm), number UMIN000010667.
Cometary dust: the diversity of primitive refractory grains Wooden, D. H.; Ishii, H. A.; Zolensky, M. E.
Philosophical transactions of the Royal Society of London. Series A: Mathematical, physical, and engineering sciences,
07/2017, Letnik:
375, Številka:
2097
Journal Article
Recenzirano
Odprti dostop
Comet dust is primitive and shows significant diversity. Our knowledge of the properties of primitive cometary particles has expanded significantly through microscale investigations of cosmic dust ...samples (anhydrous interplanetary dust particles (IDPs), chondritic porous (CP) IDPs and UltraCarbonaceous Antarctic micrometeorites, Stardust and Rosetta), as well as through remote sensing (Spitzer IR spectroscopy). Comet dust are aggregate particles of materials unequilibrated at submicrometre scales. We discuss the properties and processes experienced by primitive matter in comets. Primitive particles exhibit a diverse range of: structure and typology; distribution of constituents; concentration and form of carbonaceous and refractory organic matter; Mg- and Fe-contents of the silicate minerals; sulfides; existence/abundance of type II chondrule fragments; high-temperature calcium-aluminium inclusions and ameboid-olivine aggregates; and rarely occurring Mg-carbonates and magnetite, whose explanation requires aqueous alteration on parent bodies. The properties of refractory materials imply there were disc processes that resulted in different comets having particular selections of primitive materials. The diversity of primitive particles has implications for the diversity of materials in the protoplanetary disc present at the time and in the region where the comets formed.
This article is part of the themed issue ‘Cometary science after Rosetta’.
We study the Dirichlet problem on a bounded convex domain of
R
N
, with zero boundary data, for truncated Laplacians
P
k
±
, which are degenerate elliptic operators, for
k
<
N
, defined by the upper ...and respectively lower partial sum of
k
eigenvalues of the Hessian matrix. We establish a necessary and sufficient condition (Theorem 1) in terms of the “flatness” of domains for existence of a solution for general inhomogeneous term. This result, in particular, shows that the strict convexity of the domain is sufficient for the solvability of the Dirichlet problem. The result and related ideas are applied to the solvability of the Dirichlet problem for the operator
P
k
+
with lower order term when the domain is strictly convex and the existence of principal eigenfunctions for the operator
P
1
+
. An existence theorem is presented with regard to the principal eigenvalue for the Dirichlet problem with zero-th order term for the operator
P
1
+
. A nonexistence result is established for the operator
P
k
+
with first order term when the domain has a boundary portion which is nearly flat. Furthermore, when the domain is a ball, we study the Dirichlet problem, with a constant inhomogeneous term and a possibly sign-changing first order term, and the associated eigenvalue problem.
Because tree size and age co-vary, it is difficult to separate their effects on growth and physiological function. To infer causes for age-related height-growth decline, we compared various leaf ...traits between mature (ca. 100 years) and old (ca. 300 years) trees of Pinus densiflora, having similar heights (ca. 30 m) and growing in the same stand. For many leaf traits, mature and old trees showed similar height-related trends reflecting acclimation to height-related hydraulic limitation for maintaining photosynthetic and hydraulic homeostasis. Photosynthetic capacity was constant within crowns of both age-classes, though 4.9–5.4 µmol CO₂m⁻² s⁻¹ lower for old than for mature trees. Biochemical acclimation of photosynthesis, allocating more nitrogen to treetop leaves, was observed only for mature trees. Leaf turgor loss point was also constant within crowns of both age-classes with no significant effect of age on leaf hydraulic traits. In mature trees, leaf capacitance increased, while bulk tissue elastic modulus decreased with height, whereas opposite height-related trends were observed for old trees. For both age-classes, leaf mass per area (LMA), transfusion-tissue area, and xylem area all increased with height, but LMA was ca. 30 g m⁻² greater for old than for mature trees. In old trees, mesophyll area decreased with height, suggesting anatomical acclimation to height may negatively affect photosynthetic capacity. We inferred that old trees rely more on morphological than biochemical acclimation and that such post-maturational shift in resource allocation could underlie height-growth decline of P. densiflora after reproductive maturity.
To prepare and manage urban greenspace for a hotter future, we must select trees that can tolerate or acclimate to high temperatures. Here, we compared tolerance and acclimation to high temperatures ...among nine urban tree species in Japan. Saplings were exposed to heat from different times (early and mid-summer) during the growing season in a greenhouse. With the exception of Ginko, heating in early summer did not affect whole-tree health, suggesting that most urban tree species may be able to acclimate to higher temperatures during the early growing season. However, continued exposure to higher temperatures, as well as heating from mid-summer, had negative effects on tree health, leading to wilting/browning, especially for evergreen broadleaved species whose leaves mature slowly. Cornus florida, Styrax japonicus and Morella rubra were the most vulnerable to heating, such that all heated saplings had died by the end of summer. At the leaf level, leaf maturation of the deciduous species and Morella was negatively affected by heating, whereas that of Eurya emarginata and Euonymus japonicas were not affected. These two species also showed heat tolerance, having a higher T50 (temperature where leaf quantum yield declined to 50% of maximum value due to heat stress) compared to other species, as well as heat acclimation, where T50 was higher for the heated saplings compared to the control. Our results indicate that, while some species that cannot recover from heat damage in early summer could die, others can acclimate to sustained high temperatures, as well as to late summer heat. As heatwaves are expected to become more frequent and severe due to global warming, tree species need to be screened individually to assess their ability to tolerate or acclimate to high temperature.
The dynamic interaction between the traveling charges and the molecular vibrations is critical for the charge transport in organic semiconductors. However, a direct evidence of the expected impact of ...the charge-phonon coupling on the band dispersion of organic semiconductors is yet to be provided. Here, we report on the electronic properties of rubrene single crystal as investigated by angle resolved ultraviolet photoelectron spectroscopy. A gap opening and kink-like features in the rubrene electronic band dispersion are observed. In particular, the latter results in a large enhancement of the hole effective mass (> 1.4), well above the limit of the theoretical estimations. The results are consistent with the expected modifications of the band structures in organic semiconductors as introduced by hole-phonon coupling effects and represent an important experimental step toward the understanding of the charge localization phenomena in organic materials.The charge transport properties in organic semiconductors are affected by the impact of molecular vibrations, yet it has been challenging to quantify them to date. Here, Bussolotti et al. provide direct experimental evidence on the band dispersion modified by molecular vibrations in a rubrene single crystal.
Aims
The second Diabetes Attitudes, Wishes and Needs (DAWN2) study aimed to assess psychosocial outcomes in people with diabetes across countries for benchmarking.
Methods
Surveys included new and ...adapted questions from validated questionnaires that assess health‐related quality of life, self‐management, attitudes/beliefs, social support and priorities for improving diabetes care. Questionnaires were conducted online, by telephone or in person.
Results
Participants were 8596 adults with diabetes across 17 countries. There were significant between‐country differences for all benchmarking indicators; no one country's outcomes were consistently better or worse than others. The proportion with likely depression WHO‐5 Well‐Being Index (WHO‐5) score ≤ 28 was 13.8% (country range 6.5–24.1%). Diabetes‐related distress Problem Areas in Diabetes Scale 5 (PAID‐5) score ≥ 40 was reported by 44.6% of participants (17.2–67.6%). Overall quality of life was rated ‘poor’ or ‘very poor’ by 12.2% of participants (7.6–26.1%). Diabetes had a negative impact on all aspects investigated, ranging from 20.5% on relationship with family/friends to 62.2% on physical health. Approximately 40% of participants (18.6–64.9%) reported that their medication interfered with their ability to live a normal life. The availability of person‐centred chronic illness care and support for active involvement was rated as low. Following self‐care advice for medication and diet was most common, and least common for glucose monitoring and foot examination, with marked country variation. Only 48.8% of respondents had participated in diabetes educational programmes/activities to help manage their diabetes.
Conclusions
Cross‐national benchmarking using psychometrically validated indicators can help identify areas for improvement and best practices to drive changes that improve outcomes for people with diabetes.
What's new?
Diabetes impacts on physical, emotional, social and financial aspects of life across cultures and countries, yet gaps in care exist around psychosocial and self‐management education and support.
The DAWN2 study highlights significant country variation in indicators of person‐centred diabetes care and psychosocial outcomes of diabetes.
Most people with diabetes are not actively engaged by their healthcare professionals to take control of their condition; education and psychosocial care are often unavailable.
The DAWN2 study provides new insights from four continents that may help identify unmet needs and best practices to drive changes that improve outcomes for people with diabetes.
PDF
