43 research outputs found
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Ecology of the Salix and Populus species of the Crooked River National Grassland
Riparian communities dominated by members of the
Salicaceae (Salix lasiandra, S. lutea, S. lemmonii,
Populus trichocarpa, P. tremuloides and S. exiqua) were
studied at the Crooked River National Grassland in central
Oregon. The objectives of this study were to examine the
relationships between the Salix and Populus species and
microsite to identify the principal environmental
gradients that may determine the distribution of these
species.
One hundred twenty five stands of riparian vegetation
dominated by the above members of the Salicaceae were
intensively sampled. A predetermined set of physical
variables were collected to characterize their habitats.
These variables included surface soils, stream
characteristics, vegetative characteristics, and other
physiographic variables. Canonical discriminant function
analysis was used to separate the Salix and Populus species based on the set of 19 environmental variables
stratified according to size class (i.e. sapling,
intermediate and decadent).
The Salicaceae, as a family, occupy specific habitats
in terms of surface soil characterisitics. The Salicaceae
require surface soils which have a mean pH of 7.3, a mean
macroporosity of 27.08%, a mean sand content of 53.42%, a
mean organic matter content of 6.0%, a mean coarse
material content of 28.59%, and a mean organic horizon of
0.58 cm. The remaining physical variables change for each
species.
The variables which most readily separated the
species were stream gradient and average stand distance
from the wetted channel. These two variables represented
an environmental gradient of depth to an effective water
table in relation to headwater versus valley-bottom stream
systems. P. tremuloides and S. lemmonii occupy areas of
steep stream gradient (headwater areas) and deep water
tables (more xeric microsites). Conversely, S. lasiandra,
S. lutea, S. exiqua and P. trichocarpa occupy areas of
lesser stream gradient (valley bottoms) and higher water
tables (more mesic microsites)
The Iowa Homemaker vol.4, no.1
Table of Contents
The Why of College Training for Motherhood by Lula R. Lancaster, page 3
Does Your Education Stop When You See a French Menu Card? by Katherine Goeppinger, page 4
April Showers by Ada Hayden, page 5
Better Homes by James Ford, page 6
All Is Not Silk That Rustles by Hazel B. McKibben, page 6
Make Your Own Bias Tape by Helen M. Green, page 7
Rejuvenating Our Homes by Lulu Robinson, page 8
Moronitis by H. B. Hawthorn, page 9
Unit Kitchens by Florence Busse, page 10
The Physically Fit Family by Grace Heidbreder, page 11
Early Spring Markets by Marvel Secor, page 11
Who’s There and Where by Dryden Quist, page 12
Editorial, page 13
The Eternal Question, page 14
Homemaker as Citizen, page 15
That Something Different by Rhea Fern Shultz, page 1
Meta-analysis of genome-wide association studies of asthma in ethnically diverse North American populations.
Asthma is a common disease with a complex risk architecture including both genetic and environmental factors. We performed a meta-analysis of North American genome-wide association studies of asthma in 5,416 individuals with asthma (cases) including individuals of European American, African American or African Caribbean, and Latino ancestry, with replication in an additional 12,649 individuals from the same ethnic groups. We identified five susceptibility loci. Four were at previously reported loci on 17q21, near IL1RL1, TSLP and IL33, but we report for the first time, to our knowledge, that these loci are associated with asthma risk in three ethnic groups. In addition, we identified a new asthma susceptibility locus at PYHIN1, with the association being specific to individuals of African descent (P = 3.9 × 10(-9)). These results suggest that some asthma susceptibility loci are robust to differences in ancestry when sufficiently large samples sizes are investigated, and that ancestry-specific associations also contribute to the complex genetic architecture of asthma
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Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation
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Generation of 1.54 {micro}m Radiation With Application to an Eye-Safe Laser Lidar
Energies in excess of 250 mJ at 1.54 {micro}m have been generated by Raman scattering of a Nd:YAG laser in methane and tested on an eyesafe laser lidar system
Substantial Oxygen Loss and Chemical Expansion in Lithium-Rich Layered Oxides at Moderate Delithiation
Delithiation of layered oxide electrodes triggers irreversible oxygen loss, one of the primary degradation modes in lithium-ion batteries. However, the delithiation-dependent mechanisms of oxygen loss remain poorly understood. Here, we investigate the oxygen nonstoichiometry in Li- and Mn-rich Li1.18-xNi0.21Mn0.53Co0.08O2-δ electrodes as a function of Li content by utilizing cycling protocols with long open-circuit voltage steps at varying states of charge. Surprisingly, we observe significant oxygen loss even at moderate delithiation, corresponding to 2.5, 4.0 and 7.6 mL O2 g-1 after resting at 135, 200, and 265 mAh g-1 (relative to the pristine material) for 100 h. Our observations suggest an intrinsic oxygen instability consistent with predictions of high equilibrium oxygen activity at intermediate potentials. From a mechanistic viewpoint, we show that cation disorder greatly lowers the oxygen vacancy formation energy by decreasing the coordination number of transition metals to certain oxygen ions. In addition, we observe a large chemical expansion coefficient with respect to oxygen nonstoichiometry, which is about three times greater than those of classical oxygen-deficient materials such as fluorite and perovskite oxides. Our work challenges the conventional wisdom that deep delithiation is a necessary condition for oxygen loss in layered oxide electrodes and highlights the importance of calendar aging for investigating oxygen stability
Calcination Heterogeneity in Li-rich Layered Oxides: a Systematic Study of Li2CO3 Particle Size
Li- and Mn-rich (LMR) layered oxide positive electrode materials exhibit high energy density and have earth abundant compositions relative to conventional Ni-, Mn-, and Co-oxides (NMCs). The lithiation of coprecipitated precursors is a key part of synthesis and offers opportunities for tuning the properties of LMR materials. Whereas the morphology of transition metal precursors has received substantial attention, that of Li sources has not. Using Li1.14Mn0.57Ni0.29O2 as a model system, in this work we establish a detailed understanding of LMR calcination pathways via in situ and ex situ diffraction, spectroscopy, microscopy and thermogravimetry. Our work shows that large Li2CO3 particle size modulates a previously misunderstood thermogravimetric feature present at the Li2CO3 melting point during layered oxide calcination and causes heterogeneity at larger length scales (inter-secondary particle) than previously reported (intra secondary particle). This work highlights the sensitivity of layered oxide calcination pathways to synthesis conditions and suggests design rules to minimize calcination heterogeneity in layered oxides beyond LMR
The Iowa Homemaker vol.4, no.1
Table of Contents
The Why of College Training for Motherhood by Lula R. Lancaster, page 3
Does Your Education Stop When You See a French Menu Card? by Katherine Goeppinger, page 4
April Showers by Ada Hayden, page 5
Better Homes by James Ford, page 6
All Is Not Silk That Rustles by Hazel B. McKibben, page 6
Make Your Own Bias Tape by Helen M. Green, page 7
Rejuvenating Our Homes by Lulu Robinson, page 8
Moronitis by H. B. Hawthorn, page 9
Unit Kitchens by Florence Busse, page 10
The Physically Fit Family by Grace Heidbreder, page 11
Early Spring Markets by Marvel Secor, page 11
Who’s There and Where by Dryden Quist, page 12
Editorial, page 13
The Eternal Question, page 14
Homemaker as Citizen, page 15
That Something Different by Rhea Fern Shultz, page 16</p