The distributions of deep ocean Δ14C data are often used to illustrate the rate of deep ocean circulation. The associated conventional 14C ages show a difference of 1000 years between the North ...Atlantic and the Southern Ocean and a difference of another 1000 years between the Southern Ocean and the North Pacific. These differences may be interpreted directly and mistakenly as the timescale of circulation. The characterization of the deep ocean circulation being millennial is common. Using objectively gridded, natural Δ14C “data” of Key et al. (2004), I recast Δ14C in terms of circulation by accounting for (1) long‐surface ocean reservoir 14C ages and (2) two sources of deep water formed in the North Atlantic and around Antarctica. The new distribution of “circulation 14C ages” is more consistent with the deep ocean being characterized by a centennial timescale than a millennial timescale. Also, the role of the southern sourced deep water is now made more obvious. By accounting for the two important controls on oceanic 14C that are not well known outside the field of chemical oceanography, the new map will be useful as an illustration of global deep ocean circulation to the wider scientific community and as a pedagogical tool to new students in Earth sciences and oceanography.
The remarkable correspondence between glacial‐interglacial changes in atmospheric CO2 levels and global climate over much of the Pleistocene suggests that CO2 is also a key climate change driver. ...However, there is as yet no widely accepted explanation of the low glacial CO2 levels. Here I use an intermediate‐complexity climate model to show that glacial cooling, acting on the rates of organic carbon production and decay in the ocean, can explain a significant portion of the glacial CO2 lowering. New model results show that cooling strengthens the vertical transport of organic carbon from the surface ocean to the deep ocean, reduces atmospheric pCO2, and shifts nutrients from the Atlantic basin to the Indo‐Pacific basins. The overall vertical transport is increased because the cooling effect on reducing the degradation rate of sinking particulate organic carbon is greater than on reducing the export production. This net temperature effect on atmospheric pCO2 mediated by biology is comparable to the temperature effect on atmospheric pCO2 driven by solubility, which is almost always mentioned as a large factor in the glacial CO2 levels. An implication for the future is that higher ocean temperatures will act as a positive feedback on atmospheric CO2 by reducing the vertical transport of carbon to the deep ocean and thereby increasing CO2 degassing from the ocean.
On the ‘Subject’ Matsumoto, Katsumi
GENGO KENKYU (Journal of the Linguistic Society of Japan),
2022, Letnik:
Supplement.2
Journal Article
Recenzirano
Odprti dostop
The present paper aims to elucidate the reason why the notion of subject appeared in medieval Europe but not in other parts of the world, and the linguistic motivation for the emergence of this ...syntactic category in Europe and its absence elsewhere.The appearance of the subject in the west European grammar was linguistically conditioned by the development of strict SVO word order combined with characteristic morphological attrition. Thus, the subject as a syntactic category is really a historical product in a relatively limited linguistic area which comprises those languages once called ‘Standard Average European’ by B. J. Whorf. These languages share the typologically unique feature known as ‘dummy subject’ and are described as ‘non-pro-drop’ languages. In short, the subject of these languages has resulted from the coalescence of three quite different linguistic functions which are usually grammaticalized separately ― discourse topic, morphological case marking, and semantic agent ― into a purely syntactic category.The subject, in conclusion, cannot be a part of the theory of syntax as a universal category. It is a complex and heterogeneous concept encountered only in a limited number of languages. Therefore, any syntactic theory based exclusively on the study of such languages needs to be thoroughly reexamined if it claims to be universal in any sense. Rather, we must reappraise the old grammatical traditions, radically different from that of the west European school, in order to found a theory of universal grammar in the true sense.
The elemental stoichiometry of marine phytoplankton plays a critical role in global biogeochemical cycles through its impact on nutrient cycling, secondary production, and carbon export. Although ...extensive laboratory experiments have been carried out over the years to assess the influence of different environmental drivers on the elemental composition of phytoplankton, a comprehensive quantitative assessment of the processes is still lacking. Here, we synthesized the responses of P:C and N:C ratios of marine phytoplankton to five major drivers (inorganic phosphorus, inorganic nitrogen, inorganic iron, irradiance, and temperature) by a meta-analysis of experimental data across 366 experiments from 104 journal articles. Our results show that the response of these ratios to changes in macronutrients is consistent across all the studies, where the increase in nutrient availability is positively related to changes in P:C and N:C ratios. We found that eukaryotic phytoplankton are more sensitive to the changes in macronutrients compared to prokaryotes, possibly due to their larger cell size and their abilities to regulate their gene expression patterns quickly. The effect of irradiance was significant and constant across all studies, where an increase in irradiance decreased both P:C and N:C. The P:C ratio decreased significantly with warming, but the response to temperature changes was mixed depending on the culture growth mode and the growth phase at the time of harvest. Along with other oceanographic conditions of the subtropical gyres (e.g., low macronutrient availability), the elevated temperature may explain why P:C is consistently low in subtropical oceans. Iron addition did not systematically change either P:C or N:C. Overall, our findings highlight the high stoichiometric plasticity of eukaryotes and the importance of macronutrients in determining P:C and N:C ratios, which both provide us insights on how to understand and model plankton diversity and productivity.
Using a global ocean biogeochemistry model, we examined three drivers of global ocean production C:N:P ratio: flexible phytoplankton stoichiometry, phytoplankton community composition, and regional ...production shifts. For a middle-of-the-road warming scenario (SSP2), the model predicts a substantial increase in the global export C:P ratio from 113:1 to 119:1 by the year 2100. The most important physiological driver of this stoichiometric change is the effect of the worldwide warming on cyanobacteria, followed by the effect of phosphate depletion on eukaryotes in the Southern Ocean. Also, there is a modest global shift in the phytoplankton community in favor of cyanobacteria at the expense of eukaryotes with a minimal effect on the global production stoichiometry. We find that shifts in the regional production, even in the absence of any change in phytoplankton stoichiometry or taxonomy, can change the global production C:N:P ratio. For example, enhancing the production in the polar waters, which typically have low C:N:P ratios, will have the effect of lowering the global ratio. In our model, the retreat of Antarctic sea ice has this very effect but is offset by production changes downstream and elsewhere. This study thus provides an understanding of how regional production changes can affect the global production C:N:P ratio. However, the current literature indicates substantial uncertainty in the future projections of regional production changes, so it is unclear at this time what their net effect is on the global production C:N:P ratio. Finally, our model predicts that the overall increase in the carbon content of organic matter due to flexible C:N:P ratio helps to stabilize carbon export in the face of reduced nutrient export (i.e. the decrease in C export is ~30% smaller than expected from the decrease in P export by 2100) but has a minimal effect on atmospheric CO2 uptake (~1%).
This study aims to present our surgical technique of lateral lumbar interbody fusion (LLIF) without corpectomy for lumbar vertebral fracture (LVF) associated radiculopathy. This study includes three ...patients treated with LLIF (mean age of 77.3 years, Group L) and three patients treated with PLIF (mean age of 75.7 years, Group P) to compare the surgical outcomes. The cartilage on the fractured vertebrae was aggressively resected with attention to avoid injury to the ring apophysis. The central cavity of the fractured endplate was filled with a bone graft substitute made of hydroxyapatite and collagen composite, followed by interbody fusion achieved by utilizing of a cage with sufficient length spanning the bilateral edges of the fractured vertebra. PLIF was performed with a standard technique using two interbody cages, and vertebroplasty was combined in one patient. Comparing to PLIF, LLIF could be performed with less estimated blood loss in shorter surgical time. Local kyphotic angle improved in all cases of Group L immediately after the surgery, but correction loss was observed at the final examination. The lordotic angle was lost in Group P postoperatively. Arthrodesis was achieved in all the cases. The mean VAS score for leg pain was 85.3 mm in Group L and 82.0 mm in Group P at preoperation and decreased to 8.7 mm and 11.3 mm, respectively, at postoperation. LLIF is an effective surgical option that enables stabilization of the fractured vertebra and reduces radicular pain by indirect neural decompression.
To develop a risk score that estimates 3-year and 5-year absolute risks for aneurysm growth.
From 10 cohorts of patients with unruptured intracranial aneurysms and follow-up imaging, we pooled ...individual data on sex, population, age, hypertension, history of subarachnoid hemorrhage, and aneurysm location, size, aspect ratio, and shape but not on smoking during follow-up and family history of intracranial aneurysms in 1,507 patients with 1,909 unruptured intracranial aneurysms and used aneurysm growth as outcome. With aneurysm-based multivariable Cox regression analysis, we determined predictors for aneurysm growth, which were presented as a risk score to calculate 3-year and 5-year risks for aneurysm growth by risk factor status.
Aneurysm growth occurred in 257 patients (17%) and 267 aneurysms (14%) during 5,782 patient-years of follow-up. Predictors for aneurysm growth were earlier subarachnoid hemorrhage, location of the aneurysm, age >60 years, population, size of the aneurysm, and shape of the aneurysm (ELAPSS). The 3-year growth risk ranged from <5% to >42% and the 5-year growth risk from <9% to >60%, depending on the risk factor status.
The ELAPSS score consists of 6 easily retrievable predictors and can help physicians in decision making on the need for and timing of follow-up imaging in patients with unruptured intracranial aneurysms.
Background:A global study designed to demonstrate the safety and efficacy of a transcatheter pacing system included 38 Japanese patients enrolled at 4 sites. Subgroup analysis to evaluate the ...performance of the leadless intracardiac transcatheter pacing system in Japanese patients was performed.Methods and Results:Safety and efficacy outcomes, patient and implant procedure characteristics, and patient and physician acceptability from the Japanese population were compared with those from outside Japan. Differences in patient characteristics, implant procedure characteristics and patient acceptability were observed. There were no major complications in Japanese patients and pacing thresholds remained low and stable throughout follow-up. There were no observable differences between Japanese patients and patients from outside Japan in the freedom from major complication rate at 12-months post-implant (100.0% vs. 95.7%, P=0.211) or physician acceptability.Conclusions:Although some differences in specific baseline characteristics, such as body size and pacing indication, and in implant procedure characteristics, including anticoagulation strategy and hospitalization period, were observed in the Japanese patients, transcatheter pacemaker performance was similar to that in the global trial. (Clinical Trial Registration: ClinicalTrials.gov ID NCT02004873.)
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