491 research outputs found
The effect of climate change on the economics of conservation tillage: A study based on field experiments in Indiana
This study evaluates the economics of conservation tillage (chisel till and no till) and examines how climate change will likely affect it. We use data from long-term experimental plots in Indiana to estimate how corn and soybean yields respond to weather patterns under alternative tillage practices. Yield functions are coupled with random draws of weather variables to construct distributions describing the probability that conservation tillage will result in higher profits than more intensive tillage, under current and future climatic regimes. Results suggest that, in our study area, projected climate change will make conservation tillage more attractive
The Morphology of Synovial Lining of Various Structures in Several Species as Observed with Scanning Electron Microscopy
Data concerning surface morphology of synovial lining of tendons, tendon sheaths, cruciate ligaments, infra-patellar fat pads and peripatellar synovial ridges in various species (rat, rabbit, dwarf goat, sheep, pig, dog, human) are reported on. Supportive studies with transmission electron microscopy (TEM) and light microscopy were performed.
Three principal morphological appearances of the synovium are evident. On structures with a dense fibrous architecture like tendons, tendon sheaths and cruciate ligaments the intimal cells and processes are mostly slender and may tend to orientation in the length-axis of the structure. On the peri- and infrapatellar adipose tissues two principal \u27extremes\u27 are seen: one in which the contours of the fat cells are clearly visible with fungoid shaped structures in between them, and one in which the fat cell contours are not recognizable and the intima consists of cauliflower-like cells. Transitional forms exist.
Several features observed on tendons and tendon sheaths which have not been reported on before are presented in this paper.
A consistent classification of synovium is presented
Advances in Corrosion Casting Methods
This paper briefly discusses the concept of corrosion cast preparation (primarily of blood vessels), the use of the scanning electron microscope (SEM) to study these casts and the observations which can be made, together with the merits and the limitations in various applications. A number of reviews and surveys are quoted in which the different injection media, injection methods, animal preparations and corrosion procedures are described. A new procedure of cleaning the corrosion casts with sodium hydroxide and Triton X-100 is described. The observations which can be made are listed and illustrated both on the cellular level as well as in organ systems as a whole. The discussion centers around some common misconceptions, the feasibility in various applications and the limitations of the method.
The conclusion is that the method has proven to be useful especially in conjunction with other methods. Moreover, while the concept of the method may be very straight-forward the approach and the interpretation often need careful consideration and might not be as straight-forward as one tends to expect from the simple sounding principle
FUEL CYCLE PROGRAM. A BOILING WATER REACTOR RESEARCH AND DEVELOPMENT PROGRAM. Eighth Quarterly Progress Report, April-June 1962
A frequency analysis was made of the VBWR stability test data. Interpretation of the steady-state noise observed in the stability tests involved consideration of several possible sources of excitation. One of these, a theory of water surface waves, is summarized. Visual and destructive examinations were made of selected fuel rods. Fretting corrosion of the Zircaloy-clad fuel rods against stainless steel spacers was observed. Evidence that UO/sub 2/ thermal conductivity increases with time was obtained. Hot gas isotatic pressed fuel rods failed after 316 Mwd/T irradiation and 5 months storage under water. Shakedown operation of a 7-rod test section for measuring burnout heat flux was conducted. A comparison of measured and calculated isotopic composition for uranium and plutonium isotopes after 400 Mwd/T irradiation indicated that the calculations underestimate capture in U/sup 238/ and overestimate capture in Pu/ sup 239/. Flux wire irradiations provided axial and radial flux profiles and the ratio of thermal to fast flux as a function of axial position. (M.C.G.
Effectiveness of an extracellular matrix graft (OASIS Wound Matrix) in the treatment of chronic leg ulcers: A randomized clinical trial
BackgroundVenous leg ulcers are a major cause of morbidity, economic loss, and decreased quality of life in affected patients. Recently, biomaterials derived from natural tissue sources have been used to stimulate wound closure. One such biomaterial obtained from porcine small-intestine submucosa (SIS) has shown promise as an effective treatment to manage full-thickness wounds. Our objective was to compare the effectiveness of SIS wound matrix with compression vs compression alone in healing chronic leg ulcers within 12 weeks.MethodsThis was a prospective, randomized, controlled multicenter trial. Patients were 120 patients with at least 1 chronic leg ulcer. Patients were randomly assigned to receive either weekly topical treatment of SIS plus compression therapy (n = 62) or compression therapy alone (n = 58). Ulcer size was determined at enrollment and weekly throughout the treatment. Healing was assessed weekly for up to 12 weeks. Recurrence after 6 months was recorded. The primary outcome measure was the proportion of ulcers healed in each group at 12 weeks.ResultsAfter 12 weeks of treatment, 55% of the wounds in the SIS group were healed, as compared with 34% in the standard-care group (P = .0196). None of the healed patients treated with SIS wound matrix and seen for the 6-month follow-up experienced ulcer recurrence.ConclusionsThe SIS wound matrix, as an adjunct therapy, significantly improves healing of chronic leg ulcers over compression therapy alone
Vascular Changes in Popliteal Lymph Nodes due to Antigen Challenge in Normal and Lethally Irradiated Mice
The microvascular system of the murine popliteal lymph node was investigated using scanning electron microscopy of microcorrosion casts. Time-dependent changes in the microvasculature following regional antigen challenge in normal and lymphocyte-depleted mice were studied. Normal lymph node microvasculature exhibited a significant increase in both the vascular bed and post-capillary venules containing high-endothelium in response to antigen challenge. Lymph nodes of lymphocyte-depleted mice showed no microvascular size increase following antigen challenge and a reduction in the amount of high-endothelium was observed
Piano Night at the Movies: A Recital
This is the poster and program from the recital, Piano Night at the Movies, held on October 30, 2020, at the OBU Amphitheater
The Interplay of ECM-Based Graft Materials and Mechanisms of Tissue Remodeling
Wound healing is a complex natural process that involves the recruitment of cells, the renewal of tissue composition, and the reinforcement of structural tissue architecture. Following ischemic injury or chronic disease, wound healing is delayed, and can often result in chronic inflammation or permanent morbidity. Tissue engineering strategies to harness the wound healing process include the use of naturally derived extracellular matrix (ECM) scaffolds with inherent bioactivity to both passively facilitate and actively direct healing toward a successful resolution. As the body heals, the properly designed ECM scaffold is gradually remodeled and integrated into the body, leaving behind organized tissue that provides long-term strength. Herein we explain the interplay of the ECM (i.e., its complex composition and bioactivity) with the cells of the body throughout the process of tissue remodeling, thus explaining how even a tissue-engineered xenograft material can direct the body to restore itself
A method for determining venous contribution to BOLD contrast sensory activation
While BOLD contrast reflects haemodynamic changes within capillaries serving neural tissue, it also has a venous component. Studies that have determined the relation of large blood vessels to the activation map indicate that veins are the source of the largest response, and the most delayed in time. It would be informative if the location of these large veins could be extracted from the properties of the functional responses, since vessels are not visible in BOLD contrast images. The present study describes a method for investigating whether measures taken from the functional response can reliably predict vein location, or at least be useful in down-weighting the venous contribution to the activation response, and illustrates this method using data from one subject. We combined fMRI at 3 Tesla with high-resolution anatomical imaging and MR venography to test whether the intrinsic properties of activation time courses corresponded to tissue type. Measures were taken from a gamma fit to the functional response. Mean magnitude showed a significant effect of tissue type (P veins ≈ grey matter > white matter. Mean delays displayed the same ranking across tissue types (P grey matter. However, measures for all tissue types were distributed across an overlapping range. A logistic regression model correctly discriminated 72% of the veins from grey matter in the absence of independent information of macroscopic vessels (ROC=0.72). Whilst tissue classification was not perfect for this subject, weighting the T contrast by the predicted probabilities materially reduced the venous component to the activation map
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