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The slow solar wind belt in the quiet corona, observed with the Metis coronagraph on board Solar Orbiter on May 15, 2020, during the activity minimum of the cycle 24, in a field of view extending from 3.8 R ⊙ to 7.0 R ⊙ , is formed by a slow and dense wind stream running along the coronal current sheet, accelerating in the radial direction and reaching at 6.8 R ⊙ a speed within 150 and 190 km s−1, depending on the assumptions on the velocity distribution of the neutral hydrogen atoms in the coronal plasma. The slow stream is separated by thin regions of high velocity shear from faster streams, almost symmetric relative to the current sheet, with peak velocity within 175 and 230 km s−1 at the same coronal level. The density–velocity structure of the slow wind zone is discussed in terms of the expansion factor of the open magnetic field lines that is known to be related to the speed of the quasi-steady solar wind, and in relation to the presence of a web of quasi-separatrix layers, S-web, the potential sites of reconnection that release coronal plasma into the wind. The parameters characterizing the coronal magnetic field lines are derived from 3D MHD model calculations. The S-web is found to coincide with the latitudinal region where the slow wind is observed in the outer corona and is surrounded by thin layers of open field lines expanding in a non-monotonic way. [ABSTRACT FROM AUTHOR]

We propose a new “helicity-pumping” method for energizing coronal equilibria that contain a magnetic flux rope (MFR) toward an eruption. We achieve this in a sequence of magnetohydrodynamics relaxations of small line-tied pulses of magnetic helicity, each of which is simulated by a suitable rescaling of the current-carrying part of the field. The whole procedure is “magnetogram-matching” because it involves no changes to the normal component of the field at the photospheric boundary. The method is illustrated by applying it to an observed force-free configuration whose MFR is modeled with our regularized Biotâ€"Savart law method. We find that, in spite of the bipolar character of the external field, the MFR eruption is sustained by two reconnection processes. The first, which we refer to as breakthrough reconnection, is analogous to breakout reconnection in quadrupolar configurations. It occurs at a quasi-separator inside a current layer that wraps around the erupting MFR and is caused by the photospheric line-tying effect. The second process is the classical flare reconnection, which develops at the second quasi-separator inside a vertical current layer that is formed below the erupting MFR. Both reconnection processes work in tandem with the magnetic forces of the unstable MFR to propel it through the overlying ambient field, and their interplay may also be relevant for the thermal processes occurring in the plasma of solar flares. The considered example suggests that our method will be beneficial for both the modeling of observed eruptive events and theoretical studies of eruptions in idealized magnetic configurations. [ABSTRACT FROM AUTHOR]

We exploit the difference in the thermal contraction coefficients within a device structure to create the strain patterns required to generate a homogeneous pseudo-magnetic field in a suspended graphene membrane. The interplay between supported and suspended metallic contacts creates deformations upon cooling, producing the desired non-uniform strain in the graphene membrane. This work can easily be adapted to produce other strain configurations, providing a route to strain engineering the electrical properties of graphene and other two-dimensional crystals, an area with a large body of theoretical work, but thus far little experimental progress. [ABSTRACT FROM AUTHOR]

Considerable research in ecoimmunology focuses on investigating variation in immune responses and linking this variation to physiological trade-offs, ecological traits, and environmental conditions. Variation in immune responses exists within and among individuals, among populations, and among taxonomic groupings. Understanding how variation and covariation are distributed and how they differ across these levels is necessary for drawing appropriate ecological and evolutionary inferences. Moreover, variation at the among-individual level directly connects to underlying quantitative genetic parameters. In order to fully understand immune responses in evolutionary and ecological contexts and to reveal phylogenetic constraints on evolution, statistical approaches must allow (co)variance to be partitioned among levels of individual, population, and phylogenetic organization (e.g., population, species, genera, and various higher taxa). Herein, we describe how multi-response mixed-effects models can be used to partition variation in immune responses among different hierarchical levels, specifically within-individuals, among-individuals, and among-species. We use simulated data to demonstrate that mixed models allow for proper partitioning of (co)variances. Importantly, these simulations also demonstrate that conventional statistical tools grossly misestimate relevant parameters, which urges caution in relating ecoimmunological hypotheses to existing empirical research. We conclude by discussing the advantages and caveats of a mixed-effects modeling approach. [ABSTRACT FROM AUTHOR]

Ecoimmunology utilizes techniques from traditionally laboratory-based disciplines—for example, immunology, genomics, proteomics, neuroendocrinology, and cell biology—to reveal how the immune systems of wild organisms both shape and respond to ecological and evolutionary pressures. Immunological phenotypes are embedded within a mechanistic pathway leading from genotype through physiology to shape higher-order biological phenomena. As such, “mechanisms” in ecoimmunology can refer to both the within-host processes that shape immunological phenotypes, or it can refer the ways in which different immunological phenotypes alter between-organism processes at ecological and evolutionary scales. The mechanistic questions ecoimmunologists can ask, both within-organisms and between-organisms, however, often have been limited by techniques that do not easily transfer to wild, non-model systems. Thus, a major focus in ecoimmunology has been developing and refining the available toolkit. Recently, this toolkit has been expanding at an unprecedented rate, bringing new challenges to choosing techniques and standardizing protocols across studies. By confronting these challenges, we will be able to enhance ecoimmunological inquiries into the physiological basis of life-history trade-offs; the development of low-cost biomarkers for susceptibility to disease; and the investigation of the ecophysiological underpinnings of disease ecology, behavior, and the coevolution of host–parasite systems. The technical advances in, and crossover technologies from, disciplines associated with ecoimmunology and how these advances can help us understand the mechanistic basis of immunological variability in wild species were the focus of the symposium, Methods and Mechanisms in Ecoimmunology. [ABSTRACT FROM AUTHOR]

Drivers of distribution patterns of poorly known species are among the most important aspects in conservation biology. We studied the proportion of area occupied by the large spotted genet (Genetta tigrina) and the slender mongoose (Galerella sanguine) in response to land use variables using camera-trapping data in Drakensberg Midlands, South Africa. Average estimated occupancy of large spotted genet and slender mongoose were 0.42 ± 0.10 and 0.41 ± 0.04 respectively using single season occupancy models. Altitudinal variation was found to be significant in the distribution of both species, along with human abundance for genet and availability of bushland for mongoose. Autumn influenced detection probability of both species negatively, while summer influenced slender mongoose positively. Relative human abundance was positively associated with detection probability of slender mongoose, and for large spotted genet, availability of bushland influenced positively while relative abundance of jackal (Canis mesomelas) influenced negatively. Occurrence of both species suggests that high elevations may not provide favourable ecological conditions, and bush cover appeared to be favourable habitats for both species. Either positive occurrence or detection of small carnivores to human abundance indicated their tendency to subsist in low-lying human populated areas. The present study shows the influence of a range of factors on the distribution of lesser known carnivores. [ABSTRACT FROM AUTHOR]

Coral bleaching is a significant contributor to the worldwide degradation of coral reefs and is indicative of the termination of symbiosis between the coral host and its symbiotic algae (dinoflagellate; Symbiodinium sp. complex), usually by expulsion or xenophagy (symbiophagy) of its dinoflagellates. Herein, we provide evidence that during the earliest stages of environmentally induced bleaching, heat stress and light stress generate distinctly different pathomorphological changes in the chloroplasts, while a combined heat- and light-stress exposure induces both pathomorphologies; suggesting that these stressors act on the dinoflagellate by different mechanisms. Within the first 48 hours of a heat stress (32°C) under low-light conditions, heat stress induced decomposition of thylakoid structures before observation of extensive oxidative damage; thus it is the disorganization of the thylakoids that creates the conditions allowing photo-oxidative-stress. Conversely, during the first 48 hours of a light stress (2007 µmoles m−2 s−1 PAR) at 25°C, condensation or fusion of multiple thylakoid lamellae occurred coincidentally with levels of oxidative damage products, implying that photo-oxidative stress causes the structural membrane damage within the chloroplasts. Exposure to combined heat- and light-stresses induced both pathomorphologies, confirming that these stressors acted on the dinoflagellate via different mechanisms. Within 72 hours of exposure to heat and/or light stresses, homeostatic processes (e.g., heat-shock protein and anti-oxidant enzyme response) were evident in the remaining intact dinoflagellates, regardless of the initiating stressor. Understanding the sequence of events during bleaching when triggered by different environmental stressors is important for predicting both severity and consequences of coral bleaching. [ABSTRACT FROM AUTHOR]

The leopard tortoise (Stigmochelys pardalis) is the largest of southern Africa's 13 tortoise species, and occurs in a variety of habitats from arid and semi-arid areas to mesic grassveld, savanna and bushveld. Seasonal activity patterns of S. pardalis were investigated as a function of rainfall, sex, time of day, temperature and time after sunrise on farmland in the semi-arid Nama-Karoo, South Africa. We predicted that because of seasonal rainfall, and subsequent increase in the food available, activity patterns of leopard tortoises would vary greatly among seasons, but that the primary constraint on activity levels within a season would be ambient temperature. Type of activity, time of day that the activity was performed, and the frequency that each activity was performed, differed among seasons. There was no overall seasonal difference in the level of activity with sex, but in certain seasons and with regard to specific activities, there were significant differences between the sexes. Diel activity was primarily bimodal in summer and autumn, and unimodal in winter and spring, with nonthermoregulatory activities being performed primarily in the afternoon. There was a positive correlation between number of tortoises caught and rainfall per season, but activity levels and number of tortoises walking and feeding was not correlated with seasonal rainfall. Leopard tortoise activity behaviours responded to ambient temperature, but results indicate that activity is also initiated by the time since sunrise. [ABSTRACT FROM AUTHOR]

Huddling is a behavioural energy conservation mechanism that is widely used by many small endotherms at low ambient temperatures. Huddling has many benefits, including decreasing the metabolic cost of maintaining body temperature (Tb), reducing the amount of heat lost to the environment, and increasing the local temperature of the nest. To test the effects of huddling on Tb, 10 rock hyrax, Procavia capensis, were housed in outside cages in four groups, varying from one to four individuals. iButtons® were surgically implanted into each rock hyrax to record their Tb every 15 min from August to November. Despite considerable variations in ambient temperatures, the rock hyrax were found to display some degree of heterothermy by varying their mean Tb from 36.70 to 37.72°C (n = 10) but not allowing it to drop below 33.60°C or rise above 39.67°C. Contrary to what was predicted, rock hyrax did not display any significant effects of huddling on Tb, irrespective of group size. [ABSTRACT FROM AUTHOR]

Wahlberg's epauletted fruit bat ( Epomophorus wahlbergi) feed on fleshy fruit and nectar of flowers and have an important role in pollination and seed dispersal. It was expected that their buccal morphological structures are adapted to this type of feeding. Consequently, buccal cavity and lingual structures of E. wahlbergi were examined by extended focus light microscopy (LM) and scanning electron microscopy (SEM). Morphology of the tongue of E. wahlbergi was similar to that of other fruit- and nectar-feeding bats. The elongated tongue of these bats possessed filiform and conical papillae as mechanical papillae and fungiform and circumvallate papillae as gustatory papillae that varied in distribution. Epomophorus wahlbergi had five palatal ridges and one post-dental palatal ridge, and relatively wide, flattened molar teeth. A hard, papillae structure at the posterior end of the upper palate of the upper plate, which has not been previously described, was observed. It appears that this structure works together with the palatal ridges and teeth, so that the bats crush fleshy fruits during feeding and extract the juices before discarding the pulp. Consequently, lingual and particularly palatal structures of E. wahlbergi show morphological adaptations for efficiently feeding on fleshy fruit and nectar. [ABSTRACT FROM AUTHOR]

We present a numerical investigation of the coronal evolution of a coronal mass ejection (CME) on 2005 August 22 using a three-dimensional thermodynamic magnetohydrodynamic model, the space weather modeling framework. The source region of the eruption was anemone active region (AR) 10798, which emerged inside a coronal hole. We validate our modeled corona by producing synthetic extreme-ultraviolet (EUV) images, which we compare to EIT images. We initiate the CME with an out-of-equilibrium flux rope with an orientation and chirality chosen in agreement with observations of an Hα filament. During the eruption, one footpoint of the flux rope reconnects with streamer magnetic field lines and with open field lines from the adjacent coronal hole. It yields an eruption which has a mix of closed and open twisted field lines due to interchange reconnection and only one footpoint line-tied to the source region. Even with the large-scale reconnection, we find no evidence of strong rotation of the CME as it propagates. We study the CME deflection and find that the effect of the Lorentz force is a deflection of the CME by about 3° RDue to image rights restrictions, multiple line equation(s) cannot be graphically displayed. toward the east during the first 30 minutes of the propagation. We also produce coronagraphic and EUV images of the CME, which we compare with real images, identifying a dimming region associated with the reconnection process. We discuss the implication of our results for the arrival at Earth of CMEs originating from the limb and for models to explain the presence of open field lines in magnetic clouds. [ABSTRACT FROM AUTHOR]

Sugar preferences and digestion of sugars in artificial fruit of different sugar types and concentrations were investigated in a South African facultative frugivore, the Cape white-eye (Zosterops virens). We studied sugar preferences, daily food and energy intake, and digestive efficiencies and transit times with birds that were fed artificial fruit diets comprising 6.6, 12.4 and 22% glucose and sucrose, respectively. Digestive transit rates of birds fed artificial fruit diets were faster for glucose compared with sucrose diets, irrespective of concentration. Birds showed increased food intake with decreasing glucose concentration, but showed no significant differences in these intake amounts with differing sucrose concentrations. Apparent assimilation efficiencies were lower than most nectar studies, and were generally higher for glucose fruit (79.3-85.6%) compared with sucrose fruit (69.0-78.4%). In choice tests, birds preferred sucrose over glucose of equivalent weight, irrespective of concentration. It appears likely that the Cape white-eye has high levels of sucrase activity, although further study is needed to verify this. [ABSTRACT FROM AUTHOR]

1. How body mass and body temperature influence metabolic rate has been of interest for decades. Today that interest can be seen in the form of debates over the proper scaling coefficients, and the mechanistic underpinnings of allometric models for metabolic rate in relation to body mass and body temperature. We tested explicit assumptions built into what we term the Arrhenius fractal supply (AFS) model of these relationships. This model, and its assumptions, is foundational to the controversial Metabolic Theory of Ecology. 2. In addition to predicting that the scaling exponent for body mass is 3/4, the AFS model originally predicted that metabolic responses to body temperature, measured as activation energies, should fall between 0·2 and 1·2 eV. More recently, the latter range was narrowed to 0·6 and 0·7 eV. 3. To test the AFS's predictions, we used multiple regression of ln(metabolic rate) as a function of ln(body mass) and 1/(body temperature) to fit the best scaling exponent for body mass to nine data sets of many diverse species. 4. For the majority of the data sets, in addition to not supporting a scaling exponent of 3/4, the analyses indicated that effects of body temperature sometimes fell outside the range of 0·6–0·7 eV, indicating that the predictions of the AFS model do not hold universally. 5. Effects of body temperature, however, did fall within the range of 0·2–1·2 eV. To aid interpretation of these results, we transformed activation energies into Q10s. At ecologically realistic temperatures, the values of Q10 that approximate activation energies of 0·2–1·2 eV ranged from c. 1·4 to 6·1 (where 6·1 is clearly unreasonably high). Hence, any model that predicts activation energies between 0·2 and 1·2 eV does not appear to be an informative scaling model at the organismal level. 6. The AFS model is foundational for the Metabolic Theory of Ecology. While we commend the attempt to incorporate scaling of metabolism into ecological theory, and the research it has inspired, we caution against using untested, and likely incorrect, assumptions as a foundation to a general theory of ecology. We recommend that scientists allow the data to determine the best model for incorporating energetics into ecological theory. [ABSTRACT FROM AUTHOR]

Bushbuck (Tragelaphus scriptus) are usually nocturnal, solitary, secretive and inhabit thick bush,making it difficult to estimate its density and abundance. The present study assessed simulated drive counts, distance sampling from sighting efforts, and markresighting as estimators of bushbuck population size in valley thicket and coastal bushveld-grassland habitat for management purposes. Sighting efforts using distance sampling during spring were found to be the most effective estimators of bushbuck density and abundance at Shongweni Dam and Game Reserve. Furthermore, the method had high repeatability and simplicity, and low costs. However, continued estimations are required over several years to determine whether these estimations are useful for monitoring population trends of bushbuck. [ABSTRACT FROM AUTHOR]

Habitat availability and use by bushbuck were investigated to assist with the compilation of a species-specific management plan. Eight bushbuck were fitted with radio-collars and tracked in their natural valley thicket and coastal bushveld-grassland habitat during summer. Bushbuck preferred short thicket habitat types which provided shelter and favoured forage plant species. Preference or avoidance of tall closed woodlands and high reedbeds by bushbuck was unclear and needs to be investigated further. Low closed grasslands were generally avoided, but they were still considered to be important as bushbuck feed on the fringes. [ABSTRACT FROM AUTHOR]

Geographic variation among four Common Fiscal subpopulations along an altitudinal gradient in South Africa demonstrated significant variation of 13 morphological features and 38 skeletal characters. Common Fiscals were largest in cooler, less humid, more arid areas and smallest in warmer, wetter, more humid localities, supporting Bergmann's Rule. Patterns of variation in morphology, anatomy and skeletal trends were significantly correlated with 11 climatic trends. Cardiopulmonary organ mass and blood haematocrit increased with altitude and reflected adaptations to low ambient temperatures and decreased oxygen pressures associated with high altitudes. These trends are concordant with those reported in various other avian species. [ABSTRACT FROM AUTHOR]

Little is known about snags in South African indigenous forests. Because of their value to wildlife, we initiated this study to quantify snag characteristics and dynamics. We also investigated forest structure (woody component and snags) and forest use by avian species of conservation concern. We examined tree species composition, abundance and tree size in eight Afromontane mixed Podocarpus forests in KwaZulu-Natal, South Africa. In addition, we investigated the succession of snags at the level of individual trees. Large Podocarpus species were less abundant in forests of the Dargle district than forests in the Creighton district. Mean diameter at breast height (dbh) of trees in the forests in these two districts differed significantly. Emergent and upper canopy trees (trees >50% of estimated 100% canopy height) were smaller in the Dargle district than those in the Creighton district. Although frequency of smaller trees (dbh = 10-60cm) compared with larger trees was high in both districts, forests in the Creighton district had more large trees. Snags were rare in all forests, but were larger (dbh) in forests of the Creighton district. The availability of large snags in these forests has implications for the conservation of secondary cavity nesting bird species including the Endangered Cape Parrot, Poicephalus robustus, as they are necessary for reproduction and recruitment of these birds. [ABSTRACT FROM AUTHOR]

Four populations of fiscal shrike Lanius collaris from South Africa were compared in respect of territory characteristics, territorial behaviour and time budgets. Shrikes held territories of the same size throughout the year. visual and vocal signals were used to maintain boundaries. Larger birds maintained larger territories, and were more involved in overt territorial behaviour and vigilance. They also spent less time foraging. Agonistic interactions were displayed on average 2-3 times an hour. Birds from larger territories had more interspecific encounters, while birds from smaller territories had more intraspecific encounters. The number of encounters in each territory was independent of season. Fiscal shrikes were >90% successful in territorial encounters against both conspecific and heterospecific intruders. Territory size was inversely proportional to perch density and was positively correlated with decreasing precipitation. Fiscal shrikes adapt to human-induced changes, increasing their use of artificial perches when natural perches were less common. [ABSTRACT FROM AUTHOR]

Foraging and territorial behaviour of Cape and Gurney's sugarbirds were studied in the Western Cape and eastern Free State of South Africa, respectively. Cape sugarbirds spent most of their time in territory defence and resting at all times of the day -- both at mid breeding season and at the end of the breeding season -- and only about ten percent of their time foraging. Cape sugarbirds may feed in the morning to replenish energy deficits and water imbalances experienced at night, and then maintain a high feeding rate at midday to maximize energy gain when nectar energy availability is greatest. Gurney's sugarbirds, by contrast, showed little variation in the amount of time spent feeding on nectar throughout the day. More dispersed or lower availability of food may have constrained vocal activity in Gurney's sugarbirds, which spent most of their time throughout the day perching silently on the tops of trees. In Cape sugarbirds, feeding preferences for particular Protea species changed in relation to their flowering seasons, and reduced inflorescence availability during the breeding season is related to increased perching and decreased territory defence at midday. [ABSTRACT FROM AUTHOR]

Explores the behavioral and electrophysiological central auditory process abilities of several aphasic individuals using a set of divided attention tasks. Areas associated with auditory processing involved in lesions resulting in aphasia; Evaluation of late auditory evoked potentials with and without distraction using an oddball paradigm.

In Africa, four genera represent the family Psittacidae; of these, the genus Poicephalus Swainson is endemic and comprises nine species. Three subspecies of the Cape Parrot, Poicephalus robustus (Gmelin), are often recognized. The endangered nominate subspecies, P. r. robustus, inhabits afromontane forest habitats and is endemic to South Africa. Poicephalus r. suahelicus (Reichenow) occurs in low-lying woodland in south-central Africa. The little-known third subspecies, P. r. fuscicollis (Kuhl), historically occurred from Angola through West Africa but is now common only in the Gambia where it occupies habitat similar to that of P. r. suahelicus. Validity of these subspecies has been examined using morphological and ecological characters. Poicephalus r. suahelicus and P. r. fuscicollis are most similar morphometrically and in plumage colour. The nominate subspecies and P. r. suahelicus showed several significant morphometric and colour differences, although local populations are parapatric in Mpumalanga Province, South Africa. Clancey's (1997) proposals are adopted with P. robustus considered a separate species from P. fuscicollis (with two subspecies P. f. fuscicollis and P. f. suahelicus). [ABSTRACT FROM AUTHOR]

Discusses the novels 'Barren Ground,' by Ellen Glasgow and 'O Pioneers!' by Willa Cather. Similarities of the novels; Way Glasgow shows the poverty of any link between marriage and religion; Analysis of the end of Cather's story.

Two distinct forms of glutamine synthetase (GS) have been identified in the spear tip tissues of harvested asparagus (Asparagus officinalis L. cv. Limbras 10). The GS activities were separated by anion exchange chromatography. They have distinct kinetic properties and contain polypeptides of different sizes, and the abundances of the GS isoforms change differently after harvest. Plastid GS has a 44 kD polypeptide, and during the post-harvest period the abundance of this polypeptide declined dramatically. After 5 d, the activity of plastid GS had declined to just 20% of that at harvest. Cytosolic GS has a 40 kD polypeptide and is the major constituent of the GS activity present at harvest (73% of total). After harvest, cytosolic GS activity declined by half and then, at 3 or 4 d after harvest, rose to 80% of the cytosolic GS activity present at harvest. The nitrogen metabolism of asparagus spears is significantly altered as the tissues deteriorate rapidly after harvest. We demonstrate that cytosolic GS activity increases during the post-harvest period and is likely to be a critical feature of the physiology of the tip of a harvested asparagus spear. [ABSTRACT FROM AUTHOR]

Freestone peach cultivars are distinguished from clingstone cultivars by a more extensive softening of the mesocarp tissue, and by the separation of mesocarp and endocarp during ripening. Cultivars of both types have been reported to develop exopolygalacturonase activity during ripening, but the enzyme has not been characterized in any detail. During development of freestone peaches (Prunus persica L. var Coronet), two exopolygalacturonase enzymes were detected 42, 65 and 85 d alter full bloom and in ripe fruit. During ripening one enzyme (exoPG 1) increased 36-fold and the other (exoPG 2) 90-fold but exoPG 2 accounted for a 73% of the total activity in ripe fruit. ExoPG 1 was purified 24-fold and exoPG 2 540-fold. ExoPG 2 is a slightly acidic glycoprotein. ExoPG 1 and exoPG 2 differ slightly in their pH optima and in their responses to calcium: each produces monogalacturonic acid as a reaction product. Similar enzymes were found in Flavorcrest, a semi-freestone peach. [ABSTRACT FROM AUTHOR]

Apex predators are widely threatened globally and generally considered a priority on the conservation biology agenda. The harpy eagle, Harpia harpyja, is an apex predator threatened by habitat loss and persecution and a flagship species for Neotropical conservation. We investigated the roles of social, economic and environmental factors related to livestock depredation by harpy eagles, causes of reported harpy eagle persecution by local landholders and the intent of future harpy eagle killings. We explored these issues using structured interviews with 184 local livestock owners, who had admitted killing a combined total of 181 harpy eagles. We found that livestock abundance and livestock husbandry were the best positive predictors of levels of self‐reported livestock predation by harpy eagles. Domestic livestock reported to be killed by harpy eagles (192) were mainly chickens (47.9%), followed by goats (22.4%), pigs (18.2%) and sheep (8.3%), with pets representing only ~3% of kills. Few harpy eagle killings were related to livestock predation, which accounted for less than 20% of all eagles killed. Instead, the main reason for killing harpy eagles was simple curiosity, and many interviewees reported later regretting their acts. Regarding intent to kill harpy eagles in the future, interviewees' perceptions of the threat posed to livestock and humans by eagles, and the subjective norm, were unrelated to intent to kill harpy eagles further. The single most important factor in predicting intent to kill harpy eagles was whether the interviewee had suffered livestock predation by eagles in the past. Additionally, the intention to kill eagles was negatively associated with landholding size. Most of our interviewees were relatively large landowners, but they are typically outnumbered by smallholders who are more likely to persecute harpy eagles. Consequently, education, compensation and tourism activities should be directed to smallholders to mitigate unnecessary persecution and mortality of harpy eagles. [ABSTRACT FROM AUTHOR]

Most organic ultraviolet filters are very lipophilic and some of them are difficult to quantify in the environment. This article describes an optimization method for the quantification of these compounds in sand samples with diverse compositions. The standard additions method was used. The search for a unique high‐performance liquid chromatography method to analyze all these filters along with the search for optimal detection conditions are presented in detail. The best extraction solvent was methanol, and the best conditions for analysis and detection involved the use of a high‐performance liquid chromatography system equipped with a biphenyl column (2.6 μm, 150 × 4.6 mm), and an Orbitrap MS detector. We also demonstrated that sample freeze‐drying can induce significant loss of some of the ultraviolet filters. [ABSTRACT FROM AUTHOR]

The P[sub300] event-related potential was recorded from groups of young and elderly listeners in response to monaural and binaural stimulation. An oddball stimulus paradigm was used to record responses from 19 scalp locations. When listening to binaural stimuli, the young group showed midline and central P[sub300] amplitude maxima, whereas the elderly group exhibited maximal responses in the midline and parietal regions. With monaural stimulation, the young group's responses were similar to those obtained with binaural stimulation. The elderly group, however, showed evidence of a greater contralateral hemisphere response to monaural stimulation during the early part of the P[sub300] response. These findings support the possibility that the P[sub300] neural generators may change with age with respect to temporal onset characteristics or their orientation and strength. [ABSTRACT FROM AUTHOR]

Understanding the magnetic structure of filament channels is difficult but essential for identifying the mechanism (s) responsible for solar eruptions. In this paper we characterize the magnetic field in a well-observed filament channel with two independent methods, prominence seismology and magnetohydrodynamics flux-rope modeling, and compare the results. In 2014 May and June, active region 12076 exhibited a complex of filaments undergoing repeated oscillations over the course of 12 days. We measure the oscillation periods in the region with both Global Oscillation Network Group H α and Solar Dynamics Observatory (SDO) Advanced Imaging Assembly EUV images, and then utilize the pendulum model of large-amplitude longitudinal oscillations to calculate the radius of curvature of the fields supporting the oscillating plasma from the derived periods. We also employ the regularized Biotâ€"Savart laws formalism to construct a flux-rope model of the field of the central filament in the region based on an SDO Helioseismic and Magnetic Imager magnetogram. We compare the estimated radius of curvature, location, and angle of the magnetic field in the plane of the sky derived from the observed oscillations with the corresponding magnetic-field properties extracted from the flux-rope model. We find that the two models are broadly consistent, but detailed comparisons of the model and specific oscillations often differ. Model observation comparisons such as these are important for advancing our understanding of the structure of filament channels. [ABSTRACT FROM AUTHOR]

Recent research has shown that nectar properties of flowers pollinated by generalist avian nectarivores differ markedly from those of flowers pollinated by specialist avian nectarivores. In particular, flowers pollinated by generalist avian nectarivores tend to have very dilute nectar dominated by hexose sugars. To establish whether pollinator-mediated selection can explain these traits, we tested nectar sugar preferences and digestive capabilities of the village weaver (Ploceus cucullatus), a common generalist passerine nectarivore in South Africa. When offered pairwise choices of equicaloric hexose and sucrose solutions, village weavers preferred hexose solutions at 5% and 10% sucrose equivalents (SE) but did not show significant preference for either type of sugar when higher concentrations were offered (15%, 20% and 25% SE). Birds were less efficient at absorbing sucrose than hexose sugars, as revealed by high-performance liquid chromatography (HPLC) analysis of excreta sugar content. This was true at both concentrations tested (8.22% and 25%), although apparent sucrose assimilation rates were still relatively high (89.6±2.9% at low concentrations and 93.6 ±1.7% at high concentrations). Transit times indicated that sucrose also passes through the digestive tract faster than hexose sugars, particularly when consumed at high concentrations. This may limit the rate at which sucrose can be hydrolyzed before absorption. These results indicate that hexose preferences in generalist avian nectarivores may help explain the low sucrose content in flowers pollinated by these birds. Moreover, the preference for hexose sugars in weavers was most evident at the low concentrations (ca. 9% sugar by mass) that are typical of nectar in flowers pollinated by generalist avian nectarivores. [ABSTRACT FROM AUTHOR]

An electrophoretic allozyme study of the fiscal shrike Lanius collaris, a widely distributed sub-Saharan passerine, was undertaken to investigate altitudinal variation in genetic structure within this species. It is a sedentary bird with limited dispersal so that subpopulations may be expected to show genetic isolation by distance, which may have been enhanced by Pleistocene glaciation effects. The study area was a linear altitudinal transect of four localities in the eastern half of South Africa, which ranged from sea level to an altitude of 1800 m, with the geographic distance between the furthest subpopulations being 300 km. Fourteen (40%) of the 35 electrophoretic loci examined were polymorphic. The mean percentage of polymorphic loci within populations, mean heterozygosity and mean number of alleles per locus were 0.519, 0.272 and 1.60, respectively. These values were much higher than those reported for most other avian species. The negative FIS and FIT values indicated a small excess of heterozygotes. The populations are only weakly differentiated genetically (Fg^ = 0.076). Rogers' (1972) mean genetic distance (D) was 0.094, and Nei's (1978) mean unbiased genetic distance was 0.019. A phenogram (unweighted pair group method) and a phylogenetic tree (distance Wagner network), both based on Rogers' (1972) distance, showed some degree of geographical subgrouping. The high mean value for the effective number of migrants (Nm) among demes indicated that 3.04 individuals were exchanged among demes per generation. The mean value for local genetic differentiation iFgj) and Nm indicated levels of gene flow between the different localities of fiscal shrike subpopulations. The Mantel test indicated that there was no significant relationship between the F^f values and the geographical distances between sample pairs. This study showed that the isolation-by-distance model of subpopulation structure is inappropriate for these birds. Juvenile natal dispersal distances, female divorce rates (every three years) and the distance of travel of females (although low) appear to be sufficient to maintain high levels of polymorphism and heterozygosity. These levels of polymorphism and heterozygosity, together with large amounts of gene fiow and the general lack of spatial autocorrelation imply that the populations of L. collaris may be subject to high rates of random drift. High values of sample heterozygosity suggest that fiscal shrike subpopulations have been stable for a long period and that genetic diversity has accumulated within populations. The rates of migration suggest that the 'subpopulations' of fiscal shrike act more or less as a single population extending over at least 300 km. [ABSTRACT FROM AUTHOR]

The acoustic effects of 1 -, 2-, and 3-mm vents were investigated with in-the-ear, in-the-canal, and completely-in-the-canal hearing aid shells. Real-ear sound pressure level measures were obtained from unvented and vented shells with 1 2 adults. In general, with increasing vent size, a statistically significant (p < .05) increase in the amount of low-frequency reduction, an upward shift in vent cutoff frequencies, and an upward shift in vent-associated resonances occurred for all hearing aid shell styles. There was no significant change in the slope of the low-frequency reduction across all hearing aid shell styles (p > .05), albeit the frequency response curves were shifted upward in frequency with increasing vent diameters. Only with the in-the-ear and completely-in-the-canal hearing aid shells were statistically significant (p < .05) differences found with the magnitude of vent-associated resonance as a function of vent diameter, and these differences were not consistent across the different styles. These findings suggest that venting may be used effectively to tune low-frequency responses in custom in-the-ear hearing instruments. [ABSTRACT FROM AUTHOR]

As part of mitonuclear communication, retrograde and anterograde signaling helps maintain homeostasis under basal conditions. Basal conditions, however, vary across phylogeny. At the cell-level, some mitonuclear retrograde responses can be quantified by measuring the constitutive components of oxidative stress, the balance between reactive oxygen species (ROS) and antioxidants. ROS are metabolic by-products produced by the mitochondria that can damage macromolecules by structurally altering proteins and inducing mutations in DNA, among other processes. To combat accumulating damage, organisms have evolved endogenous antioxidants and can consume exogenous antioxidants to sequester ROS before they cause cellular damage. ROS are also considered to be regulated through a retrograde signaling cascade from the mitochondria to the nucleus. These cellular pathways may have implications at the whole-animal level as well. For example, birds have higher basal metabolic rates, higher blood glucose concentration, and longer lifespans than similar sized mammals, however, the literature is divergent on whether oxidative stress is higher in birds compared with mammals. Herein, we collected literature values for whole-animal metabolism of birds and mammals. Then, we collected cellular metabolic rate data from primary fibroblast cells isolated from birds and mammals and we collected blood from a phylogenetically diverse group of birds and mammals housed at zoos and measured several parameters of oxidative stress. Additionally, we reviewed the literature on basal-level oxidative stress parameters between mammals and birds. We found that mass-specific metabolic rates were higher in birds compared with mammals. Our laboratory results suggest that cellular basal metabolism, total antioxidant capacity, circulating lipid damage, and catalase activity were significantly lower in birds compared with mammals. We found no body-size correlation on cellular metabolism or oxidative stress. We also found that most oxidative stress parameters significantly correlate with increasing age in mammals, but not in birds; and that correlations with reported maximum lifespans show different results compared with correlations with known aged birds. Our literature review revealed that basal levels of oxidative stress measurements for birds were rare, which made it difficult to draw conclusions. [ABSTRACT FROM AUTHOR]

Nestedness refers to a species distribution pattern whereby species found in species‐poor sites represent a subset of those in species‐rich sites. Nestedness is presumed to be primarily a result of selective extinction of species and thus is important for determining mechanisms of species impoverishment in fragmented landscapes. In this study, we investigated the effects of forest fragment attributes and species' life‐history traits on nestedness patterns of terrestrial mammals in an urban‐forest mosaic in EThekwini Municipality Area, Durban, South Africa. A presence/absence matrix of mammals (16 species) in forest fragments (28 fragments) was compiled based on the mammalian survey conducted using remote‐triggered camera traps. The mammalian assemblage in the study area displayed significant nestedness. The nested ranking of forest fragments was strongly correlated with fragment area and proximity index but not with shape index and foliage height diversity. The best model based on Akaike Information Criterion (AICc) showed that among species' life‐history traits, body mass, trophic level, niche breadth and sociality were the most suited as predictors of extinction vulnerability. In particular, niche breadth was strongly associated with extinction vulnerability. Thus, the ability to persist in forest fragments of various sizes as well as the ability to move to fragments with different degrees of isolation shape fragment dynamics in this landscape. Furthermore, species with broad resource requirements are more likely to persist with further habitat disturbance. Overall, this study showed the importance of integrating forest fragment attributes and ecological traits of species in nestedness analyses for determining species in most need of conservation action which is important for preventing further loss of species. [ABSTRACT FROM AUTHOR]

Stable isotope analyses are a powerful tool in understanding diets, defining trophic networks, inferring geographical origins of animals and in forensic tracing of the origins of deceased humans or illegally traded animal and plant material. African grey parrots Psittacus erithacus are one of the most traded animal species in the world, and the origin of confiscated illegal or deceased specimens are often unknown. We measured stable isotope values (δ13C, δ15N and δ2H) in different African grey parrots (n = 32) and determined feather type (i.e. primary, tail, breast) standardization values for comparing individuals. δ13C and δ2H values differed between known wild (n = 42) and captive (n = 50) birds when standardized for feather type, but not for δ15N. δ13C and δ2H values in feathers from a consignment of African grey parrots (n = 100), all of which were deceased, aligned significantly with that of known wild birds. We suggest that further analyses of feathers, across a range of spatial and temporal scales, will enhance stable isotope analyses as a valuable tool in monitoring and combatting the trade of African grey parrots. Furthermore, the use of stable isotope analyses may improve the monitoring of illegally traded bird species, and other wildlife, across the globe. Illegal trade in wildlife species is a global concern, and stable isotope analyses can be a powerful tool in forensics, tracing the origins of illegally traded animal and plant material. African grey parrots (Psittacus erithacus) are one of the most traded animal species in the world, and the origins of confiscated illegal or deceased specimens are often unknown. We demonstrate how stable isotope analyses can be used as a forensic tool to monitor illegally traded African grey parrots and potentially other wildlife, across the globe. [ABSTRACT FROM AUTHOR]

Fisheries managers have implemented suppression programmes to control non-native lake trout, Salvelinus namaycush (Walbaum), in several lakes throughout the western United States. This study determined the feasibility of experimentally suppressing lake trout using gillnets in an isolated backcountry lake in Glacier National Park, Montana, USA, for the conservation of threatened bull trout, Salvelinus confluentus (Suckley). The demographics of the lake trout population during suppression (2009-2013) were described, and those data were used to assess the effects of suppression scenarios on population growth rate ( λ) using an age-structured population model. Model simulations indicated that the population was growing exponentially ( λ = 1.23, 95% CI: 1.16-1.28) prior to suppression. However, suppression resulted in declining λ (0.61-0.79) for lake trout, which was concomitant with stable bull trout adult abundances. Continued suppression at or above observed exploitation levels is needed to ensure continued population declines. [ABSTRACT FROM AUTHOR]

Metabolic rates are correlated with many aspects of ecology, but how selection on different aspects of metabolic rates affects their mutual evolution is poorly understood. Using laboratory mice, we artificially selected for high maximal mass-independent metabolic rate (MMR) without direct selection on mass-independent basal metabolic rate (BMR). Then we tested for responses to selection in MMR and correlated responses to selection in BMR. In other lines, we antagonistically selected for mice with a combination of high mass-independent MMR and low mass-independent BMR. All selection protocols and data analyses included body mass as a covariate, so effects of selection on the metabolic rates are mass adjusted (that is, independent of effects of body mass). The selection lasted eight generations. Compared with controls, MMR was significantly higher (11.2%) in lines selected for increased MMR, and BMR was slightly, but not significantly, higher (2.5%). Compared with controls, MMR was significantly higher (5.3%) in antagonistically selected lines, and BMR was slightly, but not significantly, lower (4.2%). Analysis of breeding values revealed no positive genetic trend for elevated BMR in high-MMR lines. A weak positive genetic correlation was detected between MMR and BMR. That weak positive genetic correlation supports the aerobic capacity model for the evolution of endothermy in the sense that it fails to falsify a key model assumption. Overall, the results suggest that at least in these mice there is significant capacity for independent evolution of metabolic traits. Whether that is true in the ancestral animals that evolved endothermy remains an important but unanswered question. [ABSTRACT FROM AUTHOR]

Although chronobiology is of growing interest to scientists, physicians, and the general public, access to recent discoveries and historical perspectives is limited. Wikipedia is an online, user-written encyclopedia that could enhance public access to current understanding in chronobiology. However, Wikipedia is lacking important information and is not universally trusted. Here, 46 students in a university course edited Wikipedia to enhance public access to important discoveries in chronobiology. Students worked for an average of 9 h each to evaluate the primary literature and available Wikipedia information, nominated sites for editing, and, after voting, edited the 15 Wikipedia pages they determined to be highest priorities. This assignment (http://www.nslc.wustl.edu/courses/Bio4030/wikipedia_project.html) was easy to implement, required relatively short time commitments from the professor and students, and had measurable impacts on Wikipedia and the students. Students created 3 new Wikipedia sites, edited 12 additional sites, and cited 347 peer-reviewed articles. The targeted sites all became top hits in online search engines. Because their writing was and will be read by a worldwide audience, students found the experience rewarding. Students reported significantly increased comfort with reading, critiquing, and summarizing primary literature and benefited from seeing their work edited by other scientists and editors of Wikipedia. We conclude that, in a short project, students can assist in making chronobiology widely accessible and learn from the editorial process. [ABSTRACT FROM PUBLISHER]

Abstract: The cost and availability of platinum, together with degradation phenomena that are directly or indirectly caused by the use of a precious-metal catalyst, are major obstacles to the commercialization of incumbent polymer electrolyte membrane fuel cell (PEMFC) technologies. The Flowcath® fuel cell technology is a highly promising alternative to the conventional PEMFC that avoids many of these issues. While the anode resembles that of a conventional cell, the novel cathode employs a liquid-based polyoxometalate redox mediator and is entirely free of any precious metals. A transition-metal based redox centre within the polyoxometalate undergoes reversible reduction in the cathode and is regenerated externally using air. In this paper, the performance of the cell for different catholyte flow rates and polyoxometalate concentrations is described and a first model is developed and validated. The voltage losses are quantified and compared to the values for a conventional cell employing a standard membrane electrode assembly. [Copyright &y& Elsevier]

Summary Granulosa cell tumours are commonly identified in mares, but have rarely been identified in equine neonates. This report describes a septic neonatal foal that presented with haemoabdomen secondary to a ruptured ovarian granulosa cell tumour. The ultrasonographic appearance, successful surgical removal and histopathological appearance of the tumour is described. Juvenile ovarian granulosa cell tumours differ histologically from adult granulosa cell tumours. Ultrasound is a useful way to identify haemoabdomen and abdominal masses in foals. Juvenile granulosa cell tumour should be considered as a differential for this combination in neonatal foals. [ABSTRACT FROM AUTHOR]

Benthic marine organisms such as mollusks are often exposed to periodic oxygen deficiency (due to the tidal exposure and/or seasonal expansion of the oxygen-deficient dead zones) and pollution by metals [e.g., cadmium, (Cd)]. These stressors can strongly affect mollusks' survival; however, physiological mechanisms of their combined effects are not fully understood. We studied the effects of Cd exposure on metabolic responses to prolonged anoxia and subsequent recovery in anoxia-tolerant intertidal mollusks Crassostrea virginica (eastern oysters). Anoxia led to an onset of anaerobiosis indicated by accumulation of L-alanine, acetate, and succinate. Prolonged anoxia (for 6 days) caused a decline in the maximum activity of electron transport chain and ADP-stimulated (state 3) oxygen uptake by mitochondria (MO2), but no change in the resting (state 4) MO2 of oyster mitochondria, along with a slight but significant reduction of mitochondrial respiratory control ratio. During reoxygenation, there was a significant overshoot of mitochondrial MO2 (by up to 70% above the normoxic steady-state values) in control oysters. Mild mitochondrial uncoupling during prolonged shutdown in anoxic tissues and a subsequent strong stimulation of mitochondrial flux during recovery may help to rapidly restore redox status and protect against elevated reactive oxygen species formation in oysters. Exposure to Cd inhibits anaerobic metabolism, abolishes reoxygenation-induced stimulation of mitochondrial MO2, and leads to oxidative stress (indicated by accumulation of DNA lesions) and a loss of mitochondrial capacity during postanoxic recovery. This may result in increased sensitivity to intermittent hypoxia and anoxia in Cd-exposed mollusks and will have implications for their survival in polluted estuaries and coastal zones. [ABSTRACT FROM AUTHOR]

Wild parrots represent one of the greatest commercial interests in the legal trade in wild birds. Although it is difficult to quantify, there is a considerable illegal trade in wild parrots. Thirty-six per cent of the world's parrot species are listed by the International Union for the Conservation of Nature as threatened or near threatened, and 55% of these are threatened to some degree by trade. In this paper, we investigate the impact of protection on the number of nests that failed because of nestlings being taken by humans (hereafter nest take) and on nesting success in parrots. We collate data on parrot nest take from published and unpublished studies from Africa, Asia and Australasia, including countries and sites with and without national and local parrot protection measures in place. Nest take was insignificant in Australia, where all studies were from areas with both local and national protection. For less developed countries, levels of nest take were variable between studies, spanning the whole range from 0 to 100%. Protection significantly reduced nest take and correspondingly increased nesting success. Our results corroborate those for the Neotropics; thus, the advantages of protection appear to be independent of geographical location or political and economic conditions. We analysed data on legal trade in wild-caught parrots before and after implementation of the 1992 Wild Bird Conservation Act (which practically eliminated import of parrots to the USA) and found that there was no apparent shift in parrot imports to other global regions from the Neotropics. We suggest that conservation of parrots globally would benefit from similar legislation introduced in other regions, such as the EU (15), which is responsible for more than 60% of global imports of wild parrots. [ABSTRACT FROM AUTHOR]

The mismatch negativity (MMN) is an event-related potential that involves a negative volt-age shift of baseline electroencephalographic (EEG) activity in the approximate latency window of the N 1 and P 2 cortical potentials in response to new or novel sounds. The MMN is present at birth and has been hypothesized to serve as an automatic preconscious detector of changes in the auditory environment. Research paradigms used to extract the MMN response from EEG activity have a potential problem related to neuronal refractoriness or recovery. Both N 1 and P 2 are known to increase in amplitude with longer interstimulus intervals (ISIs). The MMN extraction procedures involve mathematical subtraction of waveforms elicited by standard sounds (with short ISIs) from those recorded to rare deviant sounds (with longer ISIs). Any ISI-dependent amplitude changes in N 1 and/or P 2 could therefore alter the morphology of the resulting difference wave and lead to misinterpretation of the nature of the underlying MMN generators. We tested 12 young females and found that the MMN can be influenced by ISI-dependent refractory effects that may modify the waveform morphology. This has important clinical implications since the MMN is being investigated as an assessment tool. [ABSTRACT FROM AUTHOR]

Extreme-ultraviolet images of Comet Lovejoy (C/2011 W3) from the Atmospheric Imaging Assembly show striations related to the magnetic field structure in both open and closed magnetic regions. The brightness contrast implies coronal density contrasts of at least a factor of six between neighboring flux tubes over scales of a few thousand kilometers. These density structures imply variations in the Alfvén speed on a similar scale. They will drastically affect the propagation and dissipation of Alfvén waves, and that should be taken into account in models of coronal heating and solar wind acceleration. In each striation, the cometary emission moves along the magnetic field and broadens with time. The speed and the rate of broadening are related to the parallel and perpendicular components of the velocities of the cometary neutrals when they become ionized. We use a magnetohydrodynamic model of the coronal magnetic field and the theory of pickup ions to compare the measurements with theoretical predictions, in particular with the energy lost to Alfvén waves as the cometary ions isotropize. [ABSTRACT FROM AUTHOR]

Objective: To identify the impact of co-morbidity on the quality of life (QoL) of patients suffering from head and neck squamous cell cancer (HNSCC) during radiation treatment. Methods: A total of 250 patients diagnosed with HNSCC between August 2001 and February 2003 underwent QoL and psychological profile assessment using the University of Washington QoL instrument (UWQoL) and the Hospital Anxiety and Depression Scale (HADS) respectively. The assessment was performed prospectively at the beginning and at two time points during radiation therapy. Co-morbidity burden was assessed retrospectively by case note analysis of 112 patients using the Adult Co-morbidity Evaluation 27 (ACE-27) index, which is a previously described and validated instrument. Demographic and tumour data were obtained from prospective databases. Co-morbidity burden and impact of co-morbidity on QoL were the main outcome measures estimated. Results: All data was analysed using SPSS for Windows V 10. Mean co-morbidity burden in this group was 1.10. Fifty eight percent of patients had some form of co-morbid illness. Co-morbidity grades did not influence the QoL and HADS scores before treatment (one wayanova). QoL and HADS scores deteriorated during radiation treatment. The change in scores after treatment was not influenced by co-morbidity in this population (one wayanova). Conclusions: This study shows that the co-morbidity burden seen in HNSCC bears no influence on the treatment related QoL and psychological profile during radiation therapy. Severe co-morbidity may have a greater effect on patients QoL and HADS score, but small sample size does not make this statistically significant. [ABSTRACT FROM AUTHOR]

The objective of this study is to define the attachment surfaces that will control intestinal epithelial cells’ growth and differentiation for the design of intestinal tissue engineering scaffolds. Methods: Intestinal epithelial cells were transduced with the green fluorescent protein gene as a stable marker by lentiviral transfection. Cells were seeded on collagen gel or polystyrene at 20,000 cells/cm2. Cellular attachment efficiency and cellular growth rate were measured by quantitative fluorometry. Cellular differentiation was determined by measuring the alkaline phosphatase activity and its mRNA level by real-time polymerase chain reaction. Student’s t-test was employed for statistical analysis. Results: Intestinal epithelial cells adhered equally well to collagen gel and to polystyrene (n = 10, p > 0.05). Cells grew rapidly on polystyrene, with a specific growth rate of 0.5 day–1 (see figure). The alkaline phosphatase activity of these cells was nearly zero. In contrast, cells seeded on collagen gel ceased to grow but exhibited high alkaline phosphatase activity. The increase in alkaline phosphatase activity was accompanied by a corresponding increase in the level of alkaline phosphatase mRNA. Conclusion: Intestinal epithelial cells can change their behavior in response to surface modification. Whereas cells on polystyrene behaved as proliferative crypt cells, cells on collagen gel behaved as differentiated villus cells. These surfaces will be useful in the design of scaffolds that mimic regions of crypts and villi for intestinal tissue engineering. [Copyright &y& Elsevier]