ABSTRACT
Phenotypic traits and their associated trade-offs have been shown to have globally consistent effects on individual plant physiological functions, but how these effects scale up to influence competition, a key driver of community assembly in terrestrial vegetation, has remained unclear. Here we use growth data from more than 3 million trees in over 140,000 plots across the world to show how three key functional traits--wood density, specific leaf area and maximum height--consistently influence competitive interactions. Fast maximum growth of a species was correlated negatively with its wood density in all biomes, and positively with its specific leaf area in most biomes. Low wood density was also correlated with a low ability to tolerate competition and a low competitive effect on neighbours, while high specific leaf area was correlated with a low competitive effect. Thus, traits generate trade-offs between performance with competition versus performance without competition, a fundamental ingredient in the classical hypothesis that the coexistence of plant species is enabled via differentiation in their successional strategies. Competition within species was stronger than between species, but an increase in trait dissimilarity between species had little influence in weakening competition. No benefit of dissimilarity was detected for specific leaf area or wood density, and only a weak benefit for maximum height. Our trait-based approach to modelling competition makes generalization possible across the forest ecosystems of the world and their highly diverse species composition.
Subject(s)
Phenotype , Trees/anatomy & histology , Trees/physiology , Forests , Internationality , Models, Biological , Plant Leaves/physiology , Trees/growth & development , Wood/analysisABSTRACT
Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives.
Subject(s)
Access to Information , Ecosystem , Biodiversity , Ecology , PlantsABSTRACT
Klippel-Trenaunay syndrome( KTS) is a complex congenital anomaly characterized by lower extremity varix and venous malformations, port-wine stains, and soft tissue and bone hypertrophy. We present a case of a 35-year-old man of KTS with pulmonary embolism (PE). The patient was referred to our hospital complaining of the leg pain and sudden onset of dyspnea. Enhanced computed tomography (CT) showed lower extremity varices, superficial thrombophlebitis and bilateral pulmonary thrombi. No venous malformations except for varicose veins were revealed in the limbs or pelvis. The patient received adequate anticoagulant therapy with edoxaban, followed by intravenous radiofrequency ablation for lower extremity varices. Two months after the operation, the patient suffered from thrombophlebitis in the leg again, however, CT showed no pulmonary thrombus. This case report suggests that intravenous ablation for lower extremity varices in KTS prevented recurrent PE.
Subject(s)
Klippel-Trenaunay-Weber Syndrome/complications , Lower Extremity/blood supply , Pulmonary Embolism/prevention & control , Varicose Veins , Adult , Catheter Ablation , Humans , Male , RecurrenceABSTRACT
Accurate estimation of tree and forest biomass is key to evaluating forest ecosystem functions and the global carbon cycle. Allometric equations that estimate tree biomass from a set of predictors, such as stem diameter and tree height, are commonly used. Most allometric equations are site specific, usually developed from a small number of trees harvested in a small area, and are either species specific or ignore interspecific differences in allometry. Due to lack of site-specific allometries, local equations are often applied to sites for which they were not originally developed (foreign sites), sometimes leading to large errors in biomass estimates. In this study, we developed generic allometric equations for aboveground biomass and component (stem, branch, leaf, and root) biomass using large, compiled data sets of 1203 harvested trees belonging to 102 species (60 deciduous angiosperm, 32 evergreen angiosperm, and 10 evergreen gymnosperm species) from 70 boreal, temperate, and subtropical natural forests in Japan. The best generic equations provided better biomass estimates than did local equations that were applied to foreign sites. The best generic equations included explanatory variables that represent interspecific differences in allometry in addition to stem diameter, reducing error by 4-12% compared to the generic equations that did not include the interspecific difference. Different explanatory variables were selected for different components. For aboveground and stem biomass, the best generic equations had species-specific wood specific gravity as an explanatory variable. For branch, leaf, and root biomass, the best equations had functional types (deciduous angiosperm, evergreen angiosperm, and evergreen gymnosperm) instead of functional traits (wood specific gravity or leaf mass per area), suggesting importance of other traits in addition to these traits, such as canopy and root architecture. Inclusion of tree height in addition to stem diameter improved the performance of the generic equation only for stem biomass and had no apparent effect on aboveground, branch, leaf, and root biomass at the site level. The development of a generic allometric equation taking account of interspecific differences is an effective approach for accurately estimating aboveground and component biomass in boreal, temperate, and subtropical natural forests.
Subject(s)
Biomass , Forests , Models, Biological , Environmental Monitoring , Japan , Population DynamicsABSTRACT
Numerous studies have revealed the existence of nonrandom trait distribution patterns as a sign of environmental filtering and/or biotic interactions in a community assembly process. A number of metrics with various algorithms have been used to detect these patterns without any clear guidelines. Although some studies have compared their statistical powers, the differences in performance among the metrics under the conditions close to actual studies are not clear. Therefore, the performances of five metrics of convergence and 16 metrics of divergence under alternative conditions were comparatively analyzed using a suite of simulated communities. We focused particularly on the robustness of the performances to conditions that are often uncertain and uncontrollable in actual studies; e.g., atypical trait distribution patterns stemming from the operation of multiple assembly mechanisms, a scaling of trait-function relationships, and a sufficiency of analyzed traits. Most tested metrics, for either convergence or divergence, had sufficient statistical power to distinguish nonrandom trait distribution patterns without uncertainty. However, the performances of the metrics were considerably influenced by both atypical trait distribution patterns and other uncertainties. Influences from these uncertainties varied among the metrics of different algorithms and their performances were often complementary. Therefore, under the uncertainties of an assembly process, the selection of appropriate metrics and the combined use of complementary metrics are critically important to reliably distinguish nonrandom patterns in a trait distribution. We provide a tentative list of recommended metrics for future studies.
Subject(s)
Ecosystem , Models, Biological , UncertaintyABSTRACT
In this study, we examined roles of three vegetation characteristics in provisioning of a recreation service by applying a machine-learning method to 4,708,229 spatially-explicit records of hiking activity in Japan. Then, expected impacts of land-use changes assessed and mapped based on the model. Associations between a recreation service and three vegetation characteristics were considerably variable depending on the social and natural environment such as accessibility and altitude. As a consequence, expected impacts of unit changes in vegetation characteristics on the service flow were considerably heterogeneous throughout the study area. The signs (positive or negative) of the impact can be reversed depending on the contexts even among nearby sites. Such notable but variable contributions of vegetation on a recreation service should be carefully reflected in landscape management. Even moderate changes in either the quantity or quality of vegetation can have a considerable impact on the frequency of hiking activity. Landscape management for promotion of the recreation service should be carefully designed for each locality on the grounds of the context-dependent effects of vegetation.
Subject(s)
Conservation of Natural Resources , Sports , Recreation , Altitude , Social Environment , EcosystemABSTRACT
Leiomyosarcoma of the inferior vena cava (IVC) is a rare malignancy, but has been found more frequently with recent advances in diagnostic imaging. Local recurrence and metastases are frequent with this pathology, and prognosis is poor. We report a case of a patient with leiomyosarcoma of the IVC surviving for >10 years after the first resection despite local recurrence and two metastatic recurrences to the pancreas and liver, with successful excisions following early detection on positron emission tomography-computed tomography.
ABSTRACT
Temperate forests are widely invaded by shade-tolerant shrubs and trees, including those of Eastern North America (ENA). However, it remains unknown whether these invaders are 'preadapted' for success in their new ranges due to unique aspects of their evolutionary history or whether selection due to enemy release or other postintroduction processes have driven rapid evolution in the invaded range. We sampled leaf traits of populations of woody understory invaders across light gradients in their native range in Japan and in their invaded ENA range to examine potential phenotypic shifts related to carbon gain and nitrogen use between ranges. We also measured leaf traits in three co-occurring ENA native shrub species. In their invaded range, invaders invested significantly less in leaf chlorophyll content (both per unit leaf mass and area) compared with native range populations of the same species, yet maintained similar rates of photosynthesis in low light. In addition, compared with ENA natives, ENA invaders displayed greater trait variation in response to increasing light availability (forest edges, gaps), giving them a potential advantage over ENA natives in a variety of light conditions. We conclude that, for this group of species, newly evolved phenotypes in the invaded range are more important than preadaptation for their success as shade-tolerant forest invaders.
Subject(s)
Forests , Introduced Species , Japan , Photosynthesis , Plant Leaves , TreesABSTRACT
Rapid expansion of exotic bamboos has lowered species diversity in Japan's ecosystems by hampering native plant growth. The invasive potential of bamboo, facilitated by global warming, may also affect other countries with developing bamboo industries. We examined past (1975-1980) and recent (2012) distributions of major exotic bamboos (Phyllostachys edulis and P. bambusoides) in areas adjacent to 145 weather stations in central and northern Japan. Bamboo stands have been established at 17 sites along the latitudinal and altitudinal distributional limit during the last three decades. Ecological niche modeling indicated that temperature had a strong influence on bamboo distribution. Using mean annual temperature and sun radiation data, we reproduced bamboo distribution (accuracy = 0.93 and AUC (area under the receiver operating characteristic curve) = 0.92). These results infer that exotic bamboo distribution has shifted northward and upslope, in association with recent climate warming. Then, we simulated future climate data and projected the climate change impact on the potential habitat distribution of invasive bamboos under different temperature increases (i.e., 1.5°C, 2.0°C, 3.0°C, and 4.0°C) relative to the preindustrial period. Potential habitats in central and northern Japan were estimated to increase from 35% under the current climate (1980-2000) to 46%-48%, 51%-54%, 61%-67%, and 77%-83% under 1.5°C, 2.0°C, 3.0°C, and 4.0°C warming levels, respectively. These infer that the risk areas can increase by 1.3 times even under a 1.5°C scenario and expand by 2.3 times under a 4.0°C scenario. For sustainable ecosystem management, both mitigation and adaptation are necessary: bamboo planting must be carefully monitored in predicted potential habitats, which covers most of Japan.
ABSTRACT
Aneurysms developing in a saphenous vein graft (SVG) after coronary artery bypass grafting (CABG) are an unusual complication and fistulae forming between an SVG aneurysm and a cardiac chamber are even rarer. A 71-year-old man had undergone a triple CABG with the left internal thoracic artery and double SVGs. Twenty years later, he was admitted with repeated congestive heart failure. A large true aneurysm (99 × 60 mm) developed in the mid portion of a saphenous vein graft to the right coronary artery together with a fistula with a diameter of 8 mm in the right atrium. The aneurysm was surgically resected and the fistula was closed.
Subject(s)
Aneurysm/etiology , Coronary Artery Bypass/adverse effects , Heart Diseases/etiology , Saphenous Vein/transplantation , Vascular Fistula/etiology , Aged , Aneurysm/surgery , Blood Vessel Prosthesis , Blood Vessel Prosthesis Implantation/methods , Coronary Vessels/surgery , Heart Atria/surgery , Heart Diseases/surgery , Heart Failure/etiology , Heart Failure/surgery , Humans , Male , Vascular Fistula/surgeryABSTRACT
We evaluated our hypothesis that morphological change of the aortic dissection can be predicted by serial measurements of hemostatic molecular markers. Between February 1999 and February 2003, 50 patients with chronic aortic dissection of the descending thoracic aorta were studied at random intervals of 1 to 59 months (mean, 15.4+/-14.3) after onset. Morphologies of the false lumen of the aortic dissection determined by computed tomographic (CT) images were divided into four groups. Twenty-two images had aortic dissection associated with intramural hematoma or a completely thrombosed false lumen without ulcer-like projections (group 1), 14 had a thrombosed false lumen with ulcer-like projections (group 2), 18 had patent, but a partially thrombosed false lumen (group 3), and 15 had a completely patent false lumen (group 4). Blood samples for detection of hemostatic molecular markers were collected on the same day or within 1 month of the CT scan being performed. Thrombin-antithrombin complex (TAT) and D-dimer proved to be significantly higher in group 3 than in group 1. There was no significant correlation between the external diameter and hemostatic molecular markers except for prothrombin fragments 1+2 (PTF1+2). Simultaneous determinations of these hemostatic markers and multiple CT scans were performed more than twice in 19 of the patients. These cases were divided into three groups according to the morphological changes of the false lumen in the interval; morphologically progressive, regressive and no change cases. Five cases showed reduction or disappearance of the false lumen (the regressive cases). Only one case showed that the false lumen progressively enlarged and was partially patent thereafter (the progressive case). Mean plasma levels of TAT and D-dimer were changed correlated with the morphological progressive or regressive changes. The morphology of aortic dissection was correlated with hemostatic molecular markers such as TAT or D-dimer. We concluded that the serial measurement of D-dimer and TAT is useful for predicting morphological changes in chronic aortic dissection, and it can be an alternative way to follow up for patients of aortic dissection.
Subject(s)
Antithrombin III/analysis , Aortic Aneurysm, Thoracic/blood , Aortic Dissection/blood , Fibrin Fibrinogen Degradation Products/analysis , Peptide Hydrolases/analysis , Adult , Aged , Aged, 80 and over , Aortic Dissection/diagnostic imaging , Aortic Aneurysm, Thoracic/diagnostic imaging , Biomarkers , Chronic Disease , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Tomography, X-Ray ComputedABSTRACT
Values of the international normalized ratio of prothrombin time (PT-INR) were analyzed at the time when anticoagulant-related complications developed in patients undergoing prosthetic valve replacement so as to evaluate the optimal therapeutic range in PT-INR value in Japanese patients. A total of 102 patients with a prosthetic heart valve who have been followed up at our department during the past 25 years were enrolled in this study. PT-INRs were determined regularly in these patients for the period between October 1996 and March 1999. Although no thromboembolic complications occurred during the period of this study, hemorrhagic complications developed in 26 (25.5%) patients. Three (2.9%) patients suffered from life threatening bleeding, such as cerebral bleeding and gastrointestinal bleeding and were defined as the major hemorrhagic group. Another 23 (22.5%) patients had minor bleeding complications such as nasal, gingival or subcutaneous bleeding and were defined as the minor hemorrhagic group. Mean PT-INR values were 3.8 2.0 and 3.2 1.0 at the onset of the complications in major and minor hemorrhagic groups, respectively, and there was no significant difference between the two groups. However, mean PT-INR values in the minor bleeding group differed significantly from that in a patient group with no hemorrhagic complications (N=76). Among the cases with bleeding complications, only 19% of the patients belonged to the range below 2.5 of PT-INR value and 54% of the patients were included in the range from 2.5 to 3.5 (p<0.05). In conclusion, the optimal therapeutic range between 2.5 and 3.5 in PT-INR recommended by the American Heart Association for patients with a prosthetic heart value in Western countries may be too high in Japanese patients. PT-INR below 2.5 is considered to be safe to prevent hemorrhagic complications.
Subject(s)
Anticoagulants/therapeutic use , Heart Valve Prosthesis Implantation , International Normalized Ratio , Prothrombin Time , Adult , Aged , Aged, 80 and over , Anticoagulants/standards , Aortic Valve/surgery , Female , Follow-Up Studies , Heart Valve Prosthesis Implantation/standards , Humans , International Normalized Ratio/standards , Japan , Male , Middle Aged , Mitral Valve/surgery , Postoperative Hemorrhage/etiology , Quality of Life , Treatment OutcomeABSTRACT
Atherosclerotic and dysplastic aneurysms of the extracranial internal carotid artery are rare in Japan. We have experienced only four cases since 1982. The patients were two men and two women with a mean age of 67 years (range 51 to 82 years). All four patients had a saccular type aneurysm; sizes ranged from 30 to 75 mm. Aneurysmectomy and end-to-end anastomosis of the internal carotid artery could be performed in two patients. One patient underwent aneurysmorrhaphy followed by primary closure of the internal carotid artery, and the remaining patient underwent aneurysmectomy followed by a prosthetic graft replacement (6 mm-PTFE graft). During aneurysm repair, simple arterial cross-clamping (time 18 to 57 min; mean +/- SD: 31.3 +/- 18.0 min) was used in all patients. During arterial clamping of the carotid artery in two patients, somatosensory evoked potentials and regional cerebral oxygen saturation detected by near-infrared spectroscopy remained within normal ranges. All patients survived without neurologic deficits. These findings indicate that intraluminal shunting may be unnecessary during aneurysm repair if the patient does not have obstructive disease in the contralateral carotid artery and if no somatosensory evoked potentials or regional cerebral oxygen saturation abnormalities occur during proximal arterial clamping. After aneurysmectomy, end-to-end anastomosis of the internal carotid artery is the preferred method of repair if the length of the distal internal carotid artery permits.
Subject(s)
Carotid Artery Diseases/surgery , Carotid Artery, Internal , Intracranial Aneurysm/surgery , Aged , Blood Vessel Prosthesis Implantation , Carotid Artery, Internal/surgery , Female , Humans , Male , Middle Aged , PolytetrafluoroethyleneABSTRACT
Nowadays, trauma victims are quickly transported from the scene to the therapeutic facility, therefore, even patients with traumatic aortic rupture (TAR) who were considered to be unlikely to survive several hours in the past are able to have more chance to undergo surgical treatment. In such patients who need emergency surgical repair of TAR regardless of the presence of multiple other organ injuries, massive contrast dye extravasation into the mediastinum is usually demonstrated on the contrast-enhanced computed tomography (CT) images. But, in most of the cases showing a pseudoaneurysm or dissection, delayed aortic repair is preferable when other organ injuries have therapeutic priority. The use of active adjunct means for distal support is definitely advantageous to prevent paraplegia. Heparin-bonded bypass by the use of low dose of heparin or intravenous argatroban is safe and avoids the risk of bleeding of other injured organs.
Subject(s)
Aorta, Thoracic/injuries , Aortic Rupture/surgery , Aorta, Thoracic/surgery , Aortic Rupture/diagnostic imaging , Blood Vessel Prosthesis Implantation , Humans , Stents , Tomography, X-Ray Computed , Vascular Surgical Procedures/methodsABSTRACT
Positioning a stent graft (SG) that adapts to the anatomical shape of the aorta is important to prevent complications after SG procedures to treat aortic disease. The Gianturco Z-stent has several benefits, but its rigid structure prevents adaptation to flexure. We improved this stent and studied its ability to adapt in the clinical environment. We positioned SGs and inspected their adaptability to flexure in an aortic arch model. We examined several gap lengths and strut directions, and determined the distance generated between the stent and the aortic wall. We found that adaptation was quite satisfactory with a gap of more than 10 mm or when the struts faced the major flexure or the side of the model aorta. Based on these findings and to facilitate placement, we manufactured the unibody Z-stent with 10-mm gaps. The unibody Z-stent was applied to treat thoracic and thoracoabdominal aortic disease in seven patients. The SG was positioned from the femoral or iliac artery in five patients and from an anastomosed graft to the ascending aorta after median sternotomy and bypass of the arch branches in two patients. A minor endoleak developed in one patient. None of the other six patients developed complications or died during the procedure, although one patient died in the hospital due to cerebral infarction. The unibody Z-stent was applied as a SG that adapts to flexure of the aorta and was easy to apply. The frequency of complications was apparently decreased after clinical application of the unibody Z-stent in SG treatment for thoracic and thoracoabdominal aortic disease.
Subject(s)
Aortic Diseases/surgery , Blood Vessel Prosthesis , Stents , Aged , Aged, 80 and over , Blood Vessel Prosthesis Implantation/methods , Female , Femoral Artery/surgery , Humans , Iliac Artery/surgery , Male , Middle Aged , Postoperative Complications/prevention & control , Prosthesis Design , Treatment OutcomeABSTRACT
BACKGROUND AND AIMS: Inevitable trade-offs in structure may be a basis for differentiation in plant strategies. Juvenile trees in different functional groups are characterized by specific suites of structural traits such as crown architecture and biomass distribution. The relationship between juvenile tree structure and function was tested to find out if it is robust among functionally and taxonomically similar species of the genus Shorea that coexist sympatrically in a tropical rain forest in Borneo. METHODS: The sapling structures of 18 species were compared for standardized dry masses of 5 and 30 g. Pairwise simple correlation and multiple correlation patterns among structural traits of juveniles (0.1-1.5 m in height) of 18 Shorea species were examined using Pearson's correlation and principal component analysis (PCA), respectively. The correlation was then tested between the PCA results and three indices of shade tolerance: the net photosynthetic rate, the wood density of mature trees and seed size. KEY RESULTS: The structural variation in saplings of the genus Shorea was as large as that found in sets of species with much more diverse origins. The PCA showed that both crown architecture and allocation to leaves are major sources of variation in the structures of the 18 species investigated. Of these two axes, allocation to leaves was significantly correlated with wood density and showed a limited correlation with photosynthetic rate, whereas crown architecture was significantly correlated to seed size. CONCLUSIONS: Overall, the results suggest that an allocation trade-off between leaves and other organs, which co-varied with wood density and to a certain extent with photosynthetic capacity, accounts for the difference in shade tolerance among congeneric, functionally similar species. In contrast, the relationship between the architecture and regeneration strategy differed from the pattern found between functional groups, and the function of crown architecture was ambiguous.