Abtract
Purpose
Greenhouse gas (GHG) emissions resulting from biofuel production and use often occur over many different years. Nondynamic GHG accounting methods traditionally sum the global warming ...impacts (GWIs) occurring over a 100-year period for all emissions occurring in the life cycle regardless of emission timing. When examining biofuels from a policy perspective, time horizons are chosen to determine the benefits a policy or action has over a desired time period. It is critical to only account for impacts occurring within the given time period by having consistent temporal boundaries. When calculating the GWI as a function of time, additional assumptions and data are required. These assumptions have implications on the results and are explored herein to determine their influence on the overall conclusions when comparing biofuels made from different cellulosic feedstocks.
Materials and methods
The time zero assumption of both biomass planting and harvesting was examined. Analytical time horizon choice was also tested by examining results on a 25-, 50-, 100-, and 500-year time horizon. GWIs using dynamic GHG accounting methods were compared to nondynamic GWI method results. Direct land use change (LUC) emissions were determined for the different feedstock conversion scenarios and used to calculate a payback period for switchgrass and sweet sorghum biofuel scenarios. Dynamic biofuel life cycle emissions were also modeled for biofuel scenarios where LUC emissions were negative in the case of converting cropland to forests.
Results and discussion
Biofuel life cycle emissions and GHG reductions compared to gasoline were highly sensitive to GHG accounting methods and time horizons. The time zero assumption had greater influence on the results when shorter time horizons were chosen and decreased as time horizons approached 500 years. Using the dynamic GHG accounting method, LUC payback periods were determined to be greater compared to a 0 % emission discount method. Payback periods using a discount rate of 2 and 3 % were at times greater and less than dynamic GHG accounting method results.
Conclusions
The data presented herein suggest that time zero and other temporal emission timing assumptions are important and influence the overall study results. Analytical time horizons were also shown to be important and significantly influence the overall results, as well as be important to achieving carbon mitigation goals. Dynamic GHG accounting was shown to be a more robust method than the traditional static GWI accounting method ensuring consistent temporal boundaries; however, dynamic inventories require additional emission timing details and assumptions that require more effort and resources to model.
Spectral analyses of laser-Doppler signal can delineate underlying mechanisms in response to pharmacological agents and in cross-sectional studies of healthy and clinical populations. We tested ...whether spectral analyses can detect acute changes in endothelial function in response to a 6-week intervention of repeated bouts of hyperaemia.
Eleven males performed forearm occlusion (5 s with 10 s rest) for 30 min, 5 times/week for 6 weeks on one arm; the other was an untreated control. Skin blood flow was measured using laser-Doppler fluxmetry (LDF), and endothelial function was assessed with and without nitric oxide (NO) synthase-inhibition with L-NAME in response to local heating (42 °C and 44 °C) and acetylcholine. A wavelet transform was used for spectral analysis of frequency intervals associated with physiological functions.
Basal measures were all unaffected by the hyperaemia intervention (all P > 0.05). In response to local skin heating to 42 °C, the 6 weeks hyperaemia intervention increased LDF, endothelial NO-independent and NO-dependent activity (all P ≤ 0.038). In response to peak local heating (44 °C) endothelial NO-independent and NO-dependent activity increased (both P ≤ 0.01); however, LDF did not (P > 0.2). In response to acetylcholine, LDF, endothelial NO-independent and NO-dependent activity all increased (all P ≤ 0.003) post-intervention.
Spectral analysis appears sufficiently sensitive to measure changes over time in cutaneous endothelial activity that are consistent with standard physiological (local heating) and pharmacological (acetylcholine) interventions of assessing cutaneous endothelial function, and may be useful not only in research but also clinical diagnosis and treatment.
•Examined whether wavelet analyses can detect acute changes in endothelial function•Local heating and acetylcholine responses to 6 weeks of hyperaemia training•Wavelet analysis is sensitive to changes in cutaneous endothelial activity•Data are consistent with invasive assessments of endothelial function•May be useful not only in research but also clinical diagnosis and treatment
Deep‐water mudstones are often considered as background sediments, deposited by vertical suspension fallout, and the range of transport and depositional processes are poorly understood compared with ...their shallow‐marine counterparts. This study presents a dataset from a 538·50 m thick cored succession through the Permian muddy lower Ecca Group of the Tanqua depocentre (south‐west Karoo Basin, South Africa). This study aims to characterize the range of mudstone facies, transport and depositional processes, and stacking patterns recorded in deep‐water environments prior to deposition of the Tanqua Karoo sandy basin‐floor fans. A combination of macroscopic and microscopic description techniques and ichnological analysis has defined nine sedimentary facies that stack in a repeated pattern to produce 2 to 26 m thick depositional units. The lower part of each unit is characterized by bedded mudstone deposited by dilute, low‐density turbidity currents with evidence for hyperpycnal‐flow processes and sediment remobilization. The upper part of each unit is dominated by more organic‐rich bedded mudstone with common mudstone intraclasts, deposited by debris flows and transitional flows, with scarce indicators of suspension fallout. The intensity of bioturbation and burrow size increases upward through each depositional unit, consistent with a decrease in physicochemically stressed conditions, linked to a lower sediment accumulation rate. This vertical facies transition in the single well dataset can be interpreted to represent relative sea‐level variations; the hyperpycnal stressed conditions in the lower part of the units were driven by relative sea‐level fall, and the more bioturbated upper part of the units represent backstepping, related to relative sea‐level rise. Alternatively, this facies transition may represent autogenic compensational stacking. The prevalence of sediment density flow deposits, even in positions distal or lateral to the sediment entry point, challenges the idea that deep‐water mudstones are primarily the deposits of passive rainout along continental margins.
Depression is common in patients with heart failure (HF), prognostic for adverse outcomes and purportedly related to disease severity. Psychological and physiologic factors relevant to HF were ...assessed in HF-ACTION, a large randomized study of aerobic exercise training in patients with systolic HF. The relation of objective and subjective parameters was compared with scores on the Beck Depression Inventory (BDI) to examine the hypothesis that depressive symptoms are better associated with perception of disease severity than with objective markers of HF severity. At baseline, 2,322 of 2,331 subjects entered into HF-ACTION completed questionnaires to assess depression (BDI) and quality of life (Kansas City Cardiomyopathy Questionnaire KCCQ). Objective markers of HF severity included ejection fraction, B-type natriuretic peptide, and peak oxygen consumption (using cardiopulmonary exercise testing, with evaluation of duration and respiratory exchange ratio also performed). Measures more likely to be affected by perceived functional status included New York Heart Association (NYHA) classification and the 6-minute walk test. Objective assessments of disease severity were slightly related (peak oxygen consumption) or not related (B-type natriuretic peptide and ejection fraction) to BDI scores. Using multivariate analysis (KCCQ not included), only age, gender, cardiopulmonary exercise testing duration, NYHA class, 6-minute walk distance, and peak respiratory exchange ratio independently correlated with BDI scores. In conclusion, depression was minimally related to objective assessments of severity of disease in patients with HF, but was associated with patient (and clinician) perceptions of disease severity. Addressing depression might improve symptoms in patients with HF.
Let (
V
, 0) be an isolated hypersurface singularity defined by the holomorphic function
f
:
(
C
n
,
0
)
→
(
C
,
0
)
. In our previous work, we introduced a series of novel Lie algebras associated to ...(
V
, 0), i.e.,
k
-th Yau algebra
L
k
(
V
)
,
k
≥
0
. It was defined to be the Lie algebra of derivations of the
k
-th moduli algebras
A
k
(
V
)
=
O
n
/
(
f
,
m
k
J
(
f
)
)
,
k
≥
0
, where
m
is the maximal ideal of
O
n
. I.e.,
L
k
(
V
)
:
=
Der
(
A
k
(
V
)
,
A
k
(
V
)
)
. The dimension of
L
k
(
V
)
was denoted by
λ
k
(
V
)
. The number
λ
k
(
V
)
, which was called
k
-th Yau number, is a subtle numerical analytic invariant of (
V
, 0). Furthermore, we formulated two conjectures for these
k
-th Yau number invariants: a sharp upper estimate conjecture of
λ
k
(
V
)
for weighted homogeneous isolated hypersurface singularities (see Conjecture
1.2
) and an inequality conjecture
λ
(
k
+
1
)
(
V
)
>
λ
k
(
V
)
,
k
≥
0
(see Conjecture
1.1
). In this article, we verify these two conjectures when
k
is small for large class of singularities.
Malaria control programmes currently face the challenge of maintaining, as well as accelerating, the progress made against malaria with fewer resources and uncertain funding. There is a critical need ...to determine what combination of malaria interventions confers the greatest protection against malaria morbidity and child mortality under routine conditions.
This study assesses intervention effectiveness experienced by children under the age of five exposed to both insecticide-treated nets (ITNs) and indoor residual spraying (IRS), as compared to each intervention alone, based on nationally representative survey data collected from 17 countries in sub-Saharan Africa.
Living in households with both ITNs and IRS was associated with a significant risk reduction against parasitaemia in medium and high transmission areas, 53% (95% CI 37% to 67%) and 31% (95% CI 11% to 47%) respectively. For medium transmission areas, an additional 36% (95% CI 7% to 53%) protection was garnered by having both interventions compared with exposure to only ITNs or only IRS. Having both ITNs and IRS was not significantly more protective against parasitaemia than either intervention alone in low and high malaria transmission areas. In rural and urban areas, exposure to both interventions provided significant protection against parasitaemia, 57% (95% CI 48% to 65%) and 39% (95% CI 10% to 61%) respectively; however, this effect was not significantly greater than having a singular intervention. Statistically, risk for all-cause child mortality was not significantly reduced by having both ITNs and IRS, and no additional protectiveness was detected for having dual intervention coverage over a singular intervention.
These findings suggest that greater reductions in malaria morbidity and health gains for children may be achieved with ITNs and IRS combined beyond the protection offered by IRS or ITNs alone.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
SUMMARY
The vast majority of teleseismic XKS (including SKS, SKKS and PKS) shear wave splitting studies interpret the observed splitting parameters (fast orientation and splitting time) based on the ...assumption of a spatially invariant anisotropy structure in the vicinity of a recording station. For such anisotropy structures the observed splitting parameters are either independent of the arriving azimuth of the seismic ray paths if the medium traversed by the ray paths can be represented by a single layer of anisotropy with a horizontal axis of symmetry (i.e. simple anisotropy), or demonstrate a periodic variation with respect to the arriving azimuth for a more complicated structure of anisotropy (e.g. multiple layers with a horizontal axis of symmetry, or a single layer with a dipping axis). When a recording station is located near the boundary of two or more regions with different anisotropy characteristics, the observed splitting parameters are dependent on the location of the ray piercing points. Such a piercing-point dependence is clearly observed using a total of 360 pairs of XKS splitting parameters at three stations situated near the northeastern edge of the Sichuan Basin in central China. For a given station, the fast orientations differ as much as 90°, and the azimuthal variation of the fast orientations lacks a 90° or 180° periodicity which is expected for double-layered or dipping axis anisotropy. The observed splitting parameters from the three stations are spatially most consistent when they are projected at a depth of ∼250 km, and can be explained by shear strain associated with the absolute plate motion and mantle flow deflected by the cone-shaped lithospheric root of the Sichuan Basin.
The recognition of the link between cigarette smoking and lung cancer in the 1964 Surgeon General's Report initiated definitive and comprehensive research on the identification of carcinogens in ...tobacco products and the relevant mechanisms of carcinogenesis. The resultant comprehensive data clearly illustrate established pathways of cancer induction involving carcinogen exposure, metabolic activation, DNA adduct formation, and consequent mutation of critical genes along with the exacerbating influences of inflammation, cocarcinogenesis, and tumor promotion. This mechanistic understanding has provided a framework for the regulation of tobacco products and for the development of relevant tobacco carcinogen and toxicant biomarkers that can be applied in cancer prevention. Simultaneously, the recognition of the link between smoking and lung cancer paved the way for two additional critical approaches to cancer prevention that are discussed here: detection of lung cancer at an early, curable stage, and chemoprevention of lung cancer. Recent successes in more precisely identifying at-risk populations and in decreasing lung cancer mortality with helical computed tomography screening are notable, and progress in chemoprevention continues, although challenges with respect to bringing these approaches to the general population exist. Collectively, research performed since the 1964 Report demonstrates unequivocally that the majority of deaths from lung cancer are preventable.
The term "inotrope" is familiar and intimately connected with pharmaceuticals clinically used for treatment of low cardiac output with cardiogenic shock. Traditional inotropic agents exert their ...effect by modulating calcium signaling in the myocardium. Their use is associated with poor long-term outcomes. Newer molecules in development intend to break from calcium mediation and the associated detrimental long-term effects by targeting distinct mechanisms of action to improve cardiac performance. Thus, "inotropy" does not sufficiently describe the range of potential novel pharmaceutical products. To enhance communication around and evaluation of current, emerging, and potential therapies, this review proposes a novel nuanced and holistic framework to categorize pharmacological agents that improve myocardial performance based on 3 myocardial mechanisms: calcitropes, which alter intracellular calcium concentrations; myotropes, which affect the molecular motor and scaffolding; and mitotropes, which influence energetics. Novel chemical entities can easily be incorporated into this structure, distinguishing themselves based on their mechanisms and clinical outcomes.
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