Lipid mimetics: A versatile toolbox for lipid biology and beyond

Being the principal component of biological membranes lipids are essential building blocks of life. Given their huge biological importance, the investigation of lipids, their properties, interactions and metabolic pathways is of prime importance for the fundamental understanding of living cells and organisms as well as the emergence of diseases. Different strategies have been applied to investigate lipid-mediated biological processes, one of them being the use of lipid mimetics. They structurally resemble their natural counterparts but are equipped with functionality that can be used to probe or manipulate lipid-mediated biological processes and biomembranes. Lipid mimetics therefore constitute an indispensable toolbox for lipid biology and membrane research but also beyond for potential applications in medicine or synthetic biology. Herein, we highlight recent advances in the development and application of lipid-mimicking compounds.     

Coral reef conservation in Bali in light of international best practice,a literature review

Bali, Indonesia sits within the coral triangle and is internationally recognised for its high coral reef diversity. The health of Bali’s marine ecosystems has declined in recent decades, and this is thought to be due to threats from climate change, destructive fishing practices, pollution, outbreaks coral eating invertebrates, coral disease and unsustainable tourism. As a response, multiple conservation strategies have been introduced by the island’s communities, non-government organisations and governments, with the aim of preventing further decline, as well as restoring already degraded coral reefs. This literature review provides an in-depth analysis of the tools used to conserve Bali’s coral reefs, and compares them to those used in other countries. In light of international ‘best practice’ in coral reef conservation, this review makes suggestions on how Bali could better conserve its coral reef ecosystems. These include (1) increasing its designation of official Marine Protected Areas (MPAS) and strengthening management of existing ones, (2) creating an MPA network, (3) substantially reducing marine plastic pollution, (4) continuing artificial reef construction in degraded habitats, (5) continuing to develop Bali as an ecotourism destination, (6) increasing engagement in global science to inform marine conservation decision-making, and (7) developing more marine monitoring programmes.     

High glucose represses the proliferation of tendon fibroblasts by inhibiting autophagy activation in tendon injury

Diabetic foot ulcer (DFU) is a kind of common and disabling complication of Diabetes Mellitus (DM). Emerging studies have demonstrated that tendon fibroblasts play a crucial role in remodeling phase of wound healing. However, little is known about the mechanism underlying high glucose (HG)-induced decrease in tendon fibroblasts viability. In the present study, the rat models of DFU were established, and collagen deposition, autophagy activation and cell apoptosis in tendon tissues were assessed using Hematoxylin–Eosin (HE) staining, immunohistochemistry (IHC), and TdT-mediated dUTP Nick-End Labeling (TUNEL) assay, respectively. Tendon fibroblasts were isolated from Achilles tendon of the both limbs, and the effect of HG on autophagy activation in tendon fibroblasts was assessed using Western blot analysis, Cell Counting Kit-8 (CCK-8) assay, and flow cytometry. We found that cell apoptosis was increased significantly and autophagy activation was decreased in foot tendon tissues of DFU rats compared with normal tissues. The role of HG in regulating tendon fibroblasts viability was then investigated in vitro, and data showed that HG repressed cell viability and increased cell apoptosis. Furthermore, HG treatment reduced LC3-II expression and increased p62 expression, indicating that HG repressed autophagy activation of tendon fibroblasts. The autophagy activator rapamycin reversed the effect. More importantly, rapamycin alleviated the suppressive role of HG in tendon fibroblasts viability. Taken together, our data demonstrate that HG represses tendon fibroblasts proliferation by inhibiting autophagy activation in tendon injury.     

四川蜂桶寨笼养绿尾虹雉的饲养繁殖

为提高笼养绿尾虹雉(Lophophorus lhuysi)的繁殖能力,2018和2019年在四川蜂桶寨进行了笼养绿尾虹雉的人工繁育研究.8只(3(♂),5♀)成年绿尾虹雉分别饲养在4个笼舍中,其中,2个笼舍1雄1雌,1笼舍1雄2雌,1笼舍1雌鸟单养.两年笼养绿尾虹雉共产受精卵16枚,受精率44.44％,人工孵化出雏12...     

Potential and peril of field experimentation: the use of copper to manipulate molluscan herbivores

Barriers of copper-based anti-fouling paints have become a popular method for the experimental manipulation of certain molluscan grazers, presumably by acting as a chemical barrier to movement. Although probably similar in action, copper metal can be more versatile in its application and maintenance. Its efficacy was confirmed in field experiments which examined the colonization of artificial surfaces by the intertidal red alga Halosaccion glandiforme (Rupr.). However, even though copper has the desired indirect effect on algae (i.e., the exclusion of grazers), it can still have undesirable direct effects as well, and these “costs of manipulation” must be recognized. These results demonstrate the necessity of proper controls in field experimentation, a consideration absent in many past studies. The general use of partial manipulations as control treatments appears useless for estimating artifacts associated with the use of copper barriers in particular and for other experimental manipulations in general. More meaningful controls may rely on finding multiple ways of manipulating the variable of interest.     

Surface porous fibre-reinforced composite bulk bone substitute

The aim of this study was to describe and evaluate the significance of a porous surface with bioactive glass granules (S53P4) covering an artificial bulk material based on polymethylmetacrylate (PMMA) and fibre-reinforced composite (FRC) technology. Effort was focused particularly on characters of the porous surface and biomechanical properties of the material in vitro, and test in vivo the implant in reconstruction in an experimental long bone segment defect model. The defect, 10 mm in length, created in the shaft of rabbit tibia, was reconstructed by the implant and fixed by intramedullary K-wires. The implant was incorporated within 4 weeks by new bone growth from the host bone covering particularly its posterior surface and cortex/implant junctions with bridging trabecular bone. Later, at 8 weeks, new bone was found also at the cortex/implant interface and in the medullary canal of the implant. Histometric measurements revealed direct bone/implant surface contact in 34% at the interface. Bioactive glass granules in the porous surface evoked the most direct contact with bone. The implants manufactured from PMMA only served as a control group, and showed significantly lower osteoconductive properties. Biomechanical measurements in vitro of fibre-reinforced PMMA specimens revealed values for bending strength and the flexural modulus to match them to human bone. This artificial bulk bone material based on PMMA/FRC technology seems to have proposing properties to be used as a bone substitute on load-bearing conditions. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effects of a Peracetic Acid Disinfection Protocol on the Biocompatibility and Biomechanical Properties of Human Patellar Tendon Allografts

Patellar tendon allografts, retrieved from cadaveric human donors, are widely used for replacement of damaged cruciate ligaments. In common with other tissue allografts originating from cadaveric donors, there are concerns regarding the potential for disease transmission from the donor to the recipient. Additionally, retrieval and subsequent processing protocols expose the graft to the risk of environmental contamination. For these reasons, disinfection or sterilisation protocols are necessary for these grafts before they are used clinically. A high-level disinfection protocol, utilising peracetic acid (PAA), has been developed and investigated for its effects on the biocompatibility and biomechanics of the patellar tendon allografts. PAA disinfection did not render the grafts either cytotoxic or liable to provoke an inflammatory response as assessed in vitro . However, the protocol was shown to increase the size of gaps between the tendon fibres in the matrix and render the grafts more susceptible to digestion with collagenase. Biomechanical studies of the tendons showed that PAA treatment had no effect on the ultimate tensile stress or Young's modulus of the tendons, and that ultimate strain was significantly higher in PAA treated tendons.     

Fiber architecture of the intrinsic muscles of the shoulder and arm in semiterrestrial and arboreal guenons

The internal organization of myofibers and connective tissues has important physiologic implications for muscle function and for naturalistic behavior. In this study of forelimb muscle morphology and primate locomotion, fiber architecture is examined in the intrinsic muscles of the shoulder (musculi deltoideus, infraspinatus, supraspinatus, subscapularis, teres major, and t. minor) and arm (m. coracobrachialis, biceps brachii, brachialis, and triceps brachii) in the semiterrestrial vervets (Chlorocebus aethiops) and arboreal red-tailed guenons (Cercopithecus ascanius). Wet weights and lengths of whole muscles, lengths of fasciculi and their associated proximal and distal tendons, and angles of pinnation were measured to estimate morphologic correlates of physiologic properties of individual muscles: force, velocity/excursion, energy expense, and relative isometric or isotonic contraction. Neither mean total-shoulder:total-arm ratios for muscle mass nor total reduced physiological cross-sectional area exhibited significant (P < 0.05) interspecific differences, thus emphasizing the importance of fine-tuning musculoskeletal analyses by the data collected here. The results generally support those previously published for quadriceps femoris and triceps surae of the hind limb in these species (Anapol and Barry [1996] Am. J. Phys. Anthropol. 99:429-447). The fiber architecture of the semiterrestrial vervets is largely suited for higher velocity while running on the ground. By contrast, the architectural configuration of red-tailed monkeys implies relatively isometric muscle contraction and passive storage of elastic strain energy for exploitation of the compliant canopy, where substrate components are situated beneath the sagittal plane of the animal. With respect to relative distribution of maximum potential force output among muscles of either shoulder or arm groups in these otherwise hind limb-dominated quadrupedal primates, statistically significant interspecific differences are best interpreted in light of braking, climbing, and, for vervets, the transition between ground and canopy.The interspecific differences shown here for the intrinsic muscles of the shoulder and arm underscore the significance of intramuscular morphology in reconciling structure and function with regard to locomotor behavior. Its analysis and interpretation lend support to consideration of "semiterrestrial" as a bona fide locomotor category uniquely different from what is practiced by dedicated arboreal and terrestrial quadrupeds that occasionally visit the habitat of one another. Data from a more committed terrestrial species would clarify this enigma.     

A comparison of methods for predicting vegetation type

Predictive modeling of vegetation patterns has wide application in vegetation science. In this paper I discuss three methods of predictive modeling using data from the alpine treeline ecotone as a case study. The study area is a portion of Glacier National Park, Montana. Parametric general linear models (GLM), artificial neural networks (ANN) and classification tree (CT) methods of predicting vegetation type are compared to determine the relative strength of each predictive approach and how they may be used in concert to increase understanding of important vegetation – environment relations. For each predictive method, vegetation type within the alpine treeline ecotone is predicted using a suite of environmental indicator variables including elevation, moisture potential, solar radiation potential, snow potential index, and disturbance history. Results from each of the predictive methods are compared against the real vegetation types to determine the relative accuracy of the methods.When the entire data field is examined (i.e., not evaluated by smaller spatial aggregates of data) the ANN procedure produces the most accurate predictions (=0.571); the CT predictions are the least accurate (=0.351). The predicted patterns of vegetation on the landscape are considerably different using the three methods. The GLM and CT methods produce large contiguous swaths of vegetation types throughout the study area, whereas the ANN method produces patterns with much more heterogeneity and smaller patches.When predictions are compared to reality at catchment scale, it becomes evident that the accuracy of each method varies depending upon the specific situation. The ANN procedure remains the most accurate method in the majority of the catchments, but both the GLM and PCT produce the most accurate classifications in at least one basin each.The variability in predictive ability of the three methods tested here indicates that there may not be a single best predictive method. Rather it may be important to use a suite of predictive models to help understand the environment – vegetation relationships. The ability to use multiple predictive methods to determine which spatial subunits of a landscape are outliers is important when identifying locations useful for climate change monitoring studies.     

Automated identification of Fos expression

The concentration of Fos, a protein encoded by the immediate-early gene c-fos, provides a measure of synaptic activity that may not parallel the electrical activity of neurons. Such a measure is important for the difficult problem of identifying dynamic properties of neuronal circuitries activated by a variety of stimuli and behaviours. We employ two-stage statistical pattern recognition to identify cellular nuclei that express Fos in two-dimensional sections of rat forebrain after administration of antipsychotic drugs. In stage one, we distinguish dark-stained candidate nuclei from image background by a thresholding algorithm and record size and shape measurements of these objects. In stage two, we compare performance of linear and quadratic discriminants, nearest-neighbour and artificial neural network classifiers that employ functions of these measurements to label candidate objects as either Fos nuclei, two touching Fos nuclei or irrelevant background material. New images of neighbouring brain tissue serve as test sets to assess generalizability of the best derived classification rule, as determined by lowest cross-validation misclassification rate. Three experts, two internal and one external, compare manual and automated results for accuracy assessment. Analyses of a subset of images on two separate occasions provide quantitative measures of inter- and intra-expert consistency. We conclude that our automated procedure yields results that compare favourably with those of the experts and thus has potential to remove much of the tedium, subjectivity and irreproducibility of current Fos identification methods in digital microscopy.