323 research outputs found

    Letter from Audrey Wood to Hubert Creekmore

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    Wood writes from New York City on Liebling-Wood Authors\u27 and Actors\u27 Representatives letterhead She writes to Creekmore in Jackson, Mississippi, to say that she does not believe that The Welcome is an easy novel to turn into a play. Includes envelope.https://egrove.olemiss.edu/creekmore/1051/thumbnail.jp

    Letter from Audrey Wood to Hubert Creekmore

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    Wood writes from New York City on Liebling-Wood Authors\u27 and Actors\u27 Representatives letterhead. She writes to Creekmore in Jackson, Mississippi, about Mr. Stoller working with Creekmore to adapt one of Creekmore\u27s stories for the theatre, perhaps Cotton Country. Includes envelope.https://egrove.olemiss.edu/creekmore/1054/thumbnail.jp

    A three-step procedure in SAS to analyze the time series from automatic dendrometers

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    Continuous measurements of stem radius variation in trees are obtained with automatic dendrometers that provide time series composed of seasonal tree growth and circadian rhythms of water storage and depletion. Several variables can be extracted from the raw data, such as amplitude and duration of radius increase and contraction, which are useful for understanding intra-annual tree growth, tree physiology and for performing growth-climate relationships. These measurements constitute a large dataset whose manipulation needs numerous algorithms and automatic procedures to efficiently and rapidly extract the information. This paper presents a three-step procedure using two SAS routines to extract the time series describing radius variation and associate them with environmental parameters. The first routine organizes and corrects data and generates outputs in the form of files and plots to visualize the results and improve data correction (first step). The second step consists of a reclassification of the hours of contraction or expansion that have been misclassified by the automatic process. The second routine classifies the daily patterns of stem variation into the three phases of contraction, expansion and radius increment and associates the environmental parameters (third step). An example of the procedure is given, with an explanation of the outputs generated. The advantages and shortcomings of the procedure and its importance for the intra-annual analyses of tree growth are discussed

    Dynamics of depletion and replenishment of water storage in stem and roots of black spruce measured by dendrometers

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    In the short term, trees rely on the internal storage of water because it affects their ability to sustain photosynthesis and growth. However, water is not rapidly available for transpiration from all the compartments of the plant and the living tissues of the stem act as a buffer to preclude low water potentials during peaks of transpiration. In this paper, electronic dendrometers were used from mid-June to mid-September 2008 to compare the radius variations in stem and roots of black spruce [Picea mariana (Mill.) B.S.P.] in two sites of the boreal forest of Quebec, Canada, with different soil characteristics and water retention. The duration of the daily cycles was similar between sites and measurement heights but greater amplitudes of contraction and expansion were observed on the stem and in the site with the shallowest soil organic layer. The expansion phase had higher amplitudes and lasted longer than contraction. On average, the contraction phase occurred between 07:00 and 16:30 (legal time), while expansion lasted 14.5 h. The roots in the site with the deepest organic layer showed a wider variation in the onset of contraction, which could be as late as 13:00. The probability of observing the contraction phase depended on precipitation. With a precipitation 60% probability of observing contraction between 05:00 and 21:00, decreasing to 20% with precipitation >1.1 mm h−1. These findings demonstrated that the depth of the organic layer plays an important role in maintaining the internal water reserve of trees. The dynamics of water depletion and replenishment can modify the water potential of xylem and cell turgor during the enlargement phase, thus affecting radial growth. Changes in temperature and precipitation regime could influence the dynamics of internal water storage in trees growing on shallower and drier soils

    Structural Basis of Membrane Protein Chaperoning through the Mitochondrial Intermembrane Space

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    International audienceThe exchange of metabolites between the mitochon- drial matrix and the cytosol depends on b-barrel channels in the outer membrane and a-helical carrier proteins in the inner membrane. The essential trans- locase of the inner membrane (TIM) chaperones escort these proteins through the intermembrane space, but the structural and mechanistic details remain elusive. We have used an integrated struc- tural biology approach to reveal the functional princi- ple of TIM chaperones. Multiple clamp-like binding sites hold the mitochondrial membrane proteins in a translocation-competent elongated form, thus mimicking characteristics of co-translational mem- brane insertion. The bound preprotein undergoes conformational dynamics within the chaperone bind- ing clefts, pointing to a multitude of dynamic local binding events. Mutations in these binding sites cause cell death or growth defects associated with impairment of carrier and b-barrel protein biogen- esis. Our work reveals how a single mitochondrial ‘‘transfer-chaperone’’ system is able to guide a-heli- cal and b-barrel membrane proteins in a ‘‘nascent chain-like’’ conformation through a ribosome-free compartment

    Optimizing vibration parameters of thick single-layer concrete pavements: results of the Belgian Monocrete project

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    peer reviewedThick single-layer concrete pavements are increasingly popular in Europe because they help tackle the increasing traffic loads on highways, airport taxiways, or industrial logistic platforms. They require less maintenance than other pavement materials, have a very long service life even under heavy loads, and can withstand static loads without permanent deformation. However, the environmental impact of such pavements is significant, due to the vast quantities of cement and inert materials required for each project. The MONOCRETE research project (March 2021-March 2024), funded by the Walloon GreenWin innovation cluster, brings together industrial partners (Eloy and Holcim) as well as research institutions (BRRC, CRIC-OCCN, and ULiège) with the aim of reducing this environmental impact by incorporating recycled concrete aggregates and an alternative, low-carbon cement. In addition to issues relating to concrete sustainability, the project studies the formulation and execution of thick concrete pavements. Indeed, a greater thickness will accentuate any compaction or vibration problem associated with a poor particle size distribution. The risk of bleeding or segregation is therefore increased. These issues are being studied through a combination of literature review, laboratory testing, and the execution of two test sections, implemented in fall 2022 and spring 2023. The purpose of this paper is to summarize the initial conclusions of this recent project on the vibration of thick concrete pavements.MonoCrete - Revêtement monocouche épais à base de liants alternatifs et de granulats recyclés11. Sustainable cities and communitie

    Assessment of the impact of the biological larvicide VectoMax G: Combination of Bacillus thuringiensis and Lysinibacillus sphaericus on non-target aquatic organisms in Yaoundé-Cameroon

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    There has been a renewed interest for larviciding during the recent decade. Although biological larvicides are considered not to be harmful to non-target organisms, there is still not sufficient data on the effect of new long-lasting larvicide formulations such as VectoMax G combining and on the environment especially on non-target organisms. The present study aimed to assess the possible influence of VectoMax G on the diversity and abundance of the aquatic fauna cohabiting with mosquito larvae in breeding habitats during a larviciding trial in the city of Yaoundé. Twelve districts of the city of Yaoundé divided into 6 intervention and 6 control sites were chosen for the study. In each district 4 semi-permanent or permanent aquatic habitats were followed. VectoMax G application was done once every two weeks during 6 months and aquatic organisms were collected 48 h after each treatment. All collected organisms were brought to the laboratory for identification. Physico-chemical parameters were recorded as well. A high diversity of the zooplankton was recorded in the intervention areas with 28 species collected against 14 species in the control areas. Cladocerans were the most represented group in both sites while Ostracods were found only in control sites. A total of 19 macro-invertebrates species were recorded in the control areas vs 16 species in the intervention areas. Gasteropods were the most represented groups of macro-invertebrates. Vertebrates such as larvivorous fishes and amphibians larvae were also found in approximately similar densities in both sites. The study indicated no significant influence of larviciding with VectoMax G on the diversity and abundance of the non-target aquatic fauna in the city of Yaoundé. [Abstract copyright: © 2023 Published by Elsevier Ltd.

    Adaptive changes of the Insig1/SREBP1/SCD1 set point help adipose tissue to cope with increased storage demands of obesity.

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    The epidemic of obesity imposes unprecedented challenges on human adipose tissue (WAT) storage capacity that may benefit from adaptive mechanisms to maintain adipocyte functionality. Here, we demonstrate that changes in the regulatory feedback set point control of Insig1/SREBP1 represent an adaptive response that preserves WAT lipid homeostasis in obese and insulin-resistant states. In our experiments, we show that Insig1 mRNA expression decreases in WAT from mice with obesity-associated insulin resistance and from morbidly obese humans and in in vitro models of adipocyte insulin resistance. Insig1 downregulation is part of an adaptive response that promotes the maintenance of SREBP1 maturation and facilitates lipogenesis and availability of appropriate levels of fatty acid unsaturation, partially compensating the antilipogenic effect associated with insulin resistance. We describe for the first time the existence of this adaptive mechanism in WAT, which involves Insig1/SREBP1 and preserves the degree of lipid unsaturation under conditions of obesity-induced insulin resistance. These adaptive mechanisms contribute to maintain lipid desaturation through preferential SCD1 regulation and facilitate fat storage in WAT, despite on-going metabolic stress
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