ABSTRACT
The study evaluated small-scale dairy systems with continuous grazing of pastures based on three temperate grasses festulolium (FL), tall fescue (TF), and perennial ryegrass (RG), compared with subtropical kikuyu grass (KG). All pastures were associated with white clover (Trifolium repens L.). Twelve multiparous Holstein cows were assigned to a 4 × 4 Latin square replicated three times with 14-day experimental periods. Sampling and analyses of pastures, concentrates, and animal variables followed standard procedures. FL showed a significantly (p < 0.05) higher mean sward height, but there were no differences (p > 0.05) in net herbage accumulation. There were significant differences (p < 0.05) among pastures for CP, NDF, ADF, in vitro digestibility of OM (IVOMD), and estimated metabolizable energy (eME). There were no differences (p > 0.05) between treatments for milk yield and composition, live weight, or body condition score. There were significant differences (p < 0.05) in fatty acid values for pastures in C14:0, C16:1, and C18:3n3. There were significant differences between treatments (p < 0.05) in milk contents for C18:0, C18:1t11, and C18:2c9t11. Grazing FL, TF, RG, or KY pastures showed no differences in milk yields. Higher values for C18:0, C18:1t11, and C18:2c9t11 were detected in KY, RG, and TF. RG had significantly higher MUFA than FL and higher PUFA than TF. A value under 65% of SFA, a ratio of n-6/n-3 lower than 4, and an atherogenic index of 1.7 are indicators of milk with beneficial effects for human health.
Subject(s)
Animal Feed/analysis , Dairying/methods , Fatty Acids/chemistry , Milk/chemistry , Poaceae , Animals , Cattle , Female , Lactation , Linoleic Acids, Conjugated/chemistry , Lolium , Mexico , Rain , Random Allocation , Seasons , TrifoliumABSTRACT
Our laboratory and others have reported the ability to detect individual Alzheimer's disease (AD) amyloid plaques in transgenic mouse brain in vivo by magnetic resonance imaging (MRI). Since amyloid plaques contain iron, most MRI studies attempting to detect plaques in AD transgenic mouse brain have employed techniques that exploit the paramagnetic effect of iron and have had mixed results. In the present study, using five-way anatomic spatial coregistration of MR images with three different histological techniques, properties of amyloid plaques in AD transgenic mouse brain were revealed that may explain their variable visibility in gradient- and spin-echo MR images. The results demonstrate differences in the visibility of plaques in the cortex and hippocampus, compared to plaques in the thalamus, by the different MRI sequences. All plaques were equally detectable by T(2)SE, while only thalamic plaques were reliably detectable by T(2)*GE pulse sequences. Histology revealed that cortical/hippocampal plaques have low levels of iron while thalamic plaques have very high levels. However, the paramagnetic effect of iron does not appear to be the sole factor leading to the rapid decay of transverse magnetization (short T(2)) in cortical/hippocampal plaques. Accordingly, MRI methods that rely less on iron magnetic susceptibility effect may be more successful for eventual human AD plaque MR imaging, particularly since human AD plaques more closely resemble the cortical and hippocampal plaques of AD transgenic mice than thalamic plaques.
Subject(s)
Alzheimer Disease/genetics , Alzheimer Disease/pathology , Plaque, Amyloid/pathology , Alzheimer Disease/metabolism , Amyloid Precursor Protein Secretases/genetics , Animals , Cerebral Cortex/anatomy & histology , Cerebral Cortex/pathology , Hippocampus/anatomy & histology , Hippocampus/pathology , Humans , Iron/metabolism , Magnetic Resonance Imaging/methods , Mice , Mice, Transgenic , Organ Specificity , Thalamus/anatomy & histology , Thalamus/pathologyABSTRACT
The benefits of minimal access surgery (MAS) in terms of accelerated recovery, reduced period of short-term disability, and patient outcome account for the widespread use of the laparoscopic approach by the majority of general surgeons. In adopting this approach with its current limitations and poor ergonomics, surgeons have been known to sustain surgery-related injuries encompassed by a spectrum best described as MAS-related surgeon morbidity syndromes, some of which are currently overlooked and poorly researched. Equivalent morbidities including the overuse syndrome (from overuse of certain muscle groups during long operations) have been documented in open surgery but are nowadays rare occurrences. As more advanced MAS operations are performed with long execution times, new patterns of neuromusculoskeletal injuries are being recognized. The surgical fatigue syndrome has also been described, though its complex nature is not fully understood. Virtually little is known on other long-term adverse effects on the surgeon following many years of operating from images displayed on a television monitor or LCD screen, and these include deterioration of visual acuity and function of the ocular muscles responsible for fixation-refixation of the eyeballs. The limited reported literature on the MAS-related surgeon morbidity syndromes identifies certain risk factors for these injuries pertaining to central and peripheral domains. Only improved knowledge of the etiology and underlying ergonomic factors based on investigative studies followed by improved instrumentation and operating room (OR) ergonomics will provide near- and long-term solutions.
