Area Decreased (area + decreased)

Distribution by Scientific Domains


Selected Abstracts


A new temperature-sensitive contrast mechanism for MRI: Curie temperature transition-based imaging

CONTRAST MEDIA & MOLECULAR IMAGING, Issue 1 2007
F. Settecase
Abstract A temperature-sensitive MRI contrast mechanism is proposed based on the physical property, the Curie temperature (Tc), at which a ferromagnetic material transitions to paramagnetic state and vice versa. To evaluate the feasibility of this new contrast mechanism, experiments were performed with solid gadolinium metal, which has a Tc of 20°C. In phantom and ex vivo experiments, the magnetic susceptibility artifact area decreased with increasing temperature transitioning across Tc (p,<,0.05). Similar results would be expected for a variety of ferromagnetic substances with substance-specific Tc values. Temperature-sensitive MRI contrast agents harnessing this mechanism may be used to (1) indicate regional attainment of specific temperatures in thermotherapy, (2) render an accumulated contrast agent more or less visible by the external application of appropriate heating or cooling, or (3) quantify tissue temperature based on MR image characteristics and magnetic susceptibility artifact caused by a ferromagnetic,paramagnetic transitioning substance. Copyright © 2007 John Wiley & Sons, Ltd. [source]


Effect of Inotropic Stimulation on Left Atrial Appendage Function in Atrial Myopathy of Chronic Atrial Fibrillation

ECHOCARDIOGRAPHY, Issue 4 2000
MASOOR KAMALESH M.D.
Atrial fibrillation (AF) leads to remodeling of the left atrium (LA) and left atrial appendage (LAA), resulting in atrial myopathy. Reduced LA and LAA function in chronic AF leads to thrombus formation and spontaneous echo contrast (SEC). The effect of inotropic stimulation on LAA function in patients with chronic AF is unknown. LAA emptying velocity (LAAEV) and maximal LAA area at baseline and after dobutamine were measured by transesophageal echocardiography in 14 subjects in normal sinus rhythm (NSR) and 6 subjects in AF. SEC in the LA was assessed before and after dobutamine. LAAEV increased significantly in both groups. However, the LAAEV at peak dobutamine in patients with AF remained significantly lower than the baseline LAAEV in patients who were in NSR (P= 0.009). Maximal LAA area decreased significantly with dobutamine in both groups, but LAA area at peak dose of dobutamine inpatients with AF remained greater than baseline area in those in NSR (P= 0.01). Despite the increase in LAAEV, SEC improved in only two of five patients. We conclude that during AF, the LAA responds to inotropic stimulation with only a modest improvement in function. [source]


Canopy structure in savannas along a moisture gradient on Kalahari sands

GLOBAL CHANGE BIOLOGY, Issue 3 2004
Robert J. Scholes
Abstract Measurements of tree canopy architecture were made at six savanna sites on deep, sandy soils, along a gradient of increasing aridity. There was substantial variation in the leaf area estimated within each site, using the same sample frame, but different measurement techniques. The trends in canopy properties in relation to the aridity gradient were consistent, regardless of the technique used for estimating the properties. The effective plant area index for the tree canopy (the sum of the stem area index and the leaf area index (LAI)) declined from around 2 to around 0.8 m2 m,2 over a gradient of mean annual rainfall from 1000 to 350 mm. Stems contributed 2,5% of the tree canopy plant area index. Since the tree canopy cover decreased from 50% to 20% over this aridity range, the leaf area index within the area covered by tree canopies remained fairly constant at 3,4 m2 m,2. Tree leaves tended from a horizontal orientation to a more random orientation as the aridity increased. On the same gradient, the leaf minor axis dimension decreased from around 30 mm to around 3 mm, and the mean specific leaf area decreased from 14 to 5 m2 kgha,1. There was good agreement between LAI observed in the field using a line ceptometer and the LAI inferred by the MODIS sensor on the Terra satellite platform, 2 months later in the same season. [source]


Patterns of ant species richness along elevational gradients in an arid ecosystem

GLOBAL ECOLOGY, Issue 2 2003
Nathan J. Sanders
ABSTRACT Aim In this study, we examine patterns of local and regional ant species richness along three elevational gradients in an arid ecosystem. In addition, we test the hypothesis that changes in ant species richness with elevation are related to elevation-dependent changes in climate and available area. Location Spring Mountains, Nevada, U.S.A. Methods We used pitfall traps placed at each 100-m elevational band in three canyons in the Spring Mountains. We compiled climate data from 68 nearby weather stations. We used multiple regression analysis to examine the effects of annual precipitation, average July precipitation, and maximum and minimum July temperature on ant species richness at each elevational band. Results We found that patterns of local ant species richness differed among the three gradients we sampled. Ant species richness increased linearly with elevation along two transects and peaked at mid-elevation along a third transect. This suggests that patterns of species richness based on data from single transects may not generalize to larger spatial scales. Cluster analysis of community similarity revealed a high-elevation species assemblage largely distinct from that of lower elevations. Major changes in the identity of ant species present along elevational gradients tended to coincide with changes in the dominant vegetation. Regional species richness, defined here as the total number of unique species within an elevational band in all three gradients combined, tended to increase with increasing elevation. Available area decreased with increasing elevation. Area was therefore correlated negatively with ant species richness and did not explain elevational patterns of ant species richness in the Spring Mountains. Mean July maximum and minimum temperature, July precipitation and annual precipitation combined to explain 80% of the variation in ant species richness. Main conclusions Our results suggest that in arid ecosystems, species richness for some taxa may be highest at high elevations, where lower temperatures and higher precipitation may support higher levels of primary production and cause lower levels of physiological stress. [source]


Effect of current reproduction on apparent survival, breeding dispersal, and future reproduction in barn swallows assessed by multistate capture,recapture models

JOURNAL OF ANIMAL ECOLOGY, Issue 3 2009
Michael Schaub
Summary 1Theoretical models predict a negative effect of current reproduction on breeding dispersal, survival and future reproduction, and many studies confirm these predictions. Yet, results of most previous studies may be difficult to interpret because the fate of the affected individuals cannot always be observed. Detection is almost always imperfect and some individuals emigrate from the study area, resulting in biased estimates of both survival and dispersal. 2Most studies bypass these problems with strong assumptions. We use a multistate capture,recapture model that does not require these assumptions. States are defined based on classes of reproductive success and on observed dispersal events within the study area. By accounting for imperfect detection within the study area, the model allows estimation of the effect of reproductive success on apparent survival, dispersal probabilities within the study area and the annual transition probabilities among classes of reproductive success. Based on an assumption about the estimate of real survival, the model allows the estimation of total dispersal that is not specific to a fixed study area. 3We applied this model to capture,recapture data of 2262 adult barn swallows (Hirundo rustica) sampled from 1997,2004 in eight local populations in Switzerland. 4We found that dispersal within the study area decreased with increasing reproductive success in both sexes, that reproductive success was not affected by preceding dispersal and that apparent survival of females but not of males increased with increasing reproductive success. Apparent survival of females with high reproductive success was identical to apparent survival of males suggesting that this estimate of apparent survival (0·48) was close to true survival. Total breeding dispersal was generally higher in females and it increased with decreasing reproductive success in both sexes. Current reproductive success depended on reproductive success in the preceding year suggesting that individual differences were of importance. 5Our study highlights that reproductive success was an important factor affecting breeding dispersal and population turnover. While unsuccessful males mainly remained in the local populations, many unsuccessful females left them. Population turnover of adult swallows was mainly due to unsuccessful females. [source]


Breeding bird species diversity in the Negev: effects of scrub fragmentation by planted forests

JOURNAL OF APPLIED ECOLOGY, Issue 5 2001
Eyal Shochat
Summary 1Afforestation of the Northern Negev, Israel, from 1956 resulted in patches of primarily coniferous trees that fragmented large scrubland areas. This alteration in landscape pattern was followed by immigration of mediterranean bird species to the Negev. 2We counted breeding birds, and measured various environmental variables in scrubland and planted forest patches, to test whether bird assemblages were random subsets of the regional species pool, and whether area or habitat structure was the major correlate with species abundance and distribution. 3Of 22 bird species recorded, only three appeared in both scrub and forest, showing that these two habitats were occupied by different species assemblages. In both habitats, species richness increased with area at a rate greater than that expected by random sampling. In the scrub this increase was related to area per se, while in the forest it was related to habitat diversity in terms of stand age and tree type. 4The density of forest species was unaffected by area, but specialist scrubland species declined as area decreased. We suggest that edge effects might reduce species abundance in small scrubland patches. 5Nested subset analysis indicated that, at the community level, species composition was not random. However, at the species level, the distribution of three forest-dwelling species appeared as random, as it was associated with habitat rather than with patch size. 6Our results indicate that increased diversity of breeding birds in the Northern Negev will require scrub patches larger than 50 ha among the increasingly forested landscape. In contrast, increasing forest area would hardly increase species diversity in the whole landscape. Future forest management regimes should also aim to increase habitat diversity by adding foliage layers, especially in the understorey. Exotic coniferous forests support fewer species than deciduous forests in mediterranean zones around the world. The suggested management regime may improve such forests as habitat for species-rich bird communities. [source]


Breeding bird species richness in Taiwan: distribution on gradients of elevation, primary productivity and urbanization

JOURNAL OF BIOGEOGRAPHY, Issue 2 2004
Pei-Fen Lee
Abstract Aim, To examine the richness of breeding bird species in relation to elevation, primary productivity and urbanization. Location, The island of Taiwan (120°,122° E, 22°,25° N). Methods, We arranged bird species richness (BSR) data from 288 bird censuses undertaken in Taiwan into a 2 × 2 km quadrat system and calculated average values of elevation, primary productivity [surrogated by normalized difference vegetation index (NDVI)], and urbanization (surrogated by road density and percentage of built area) for each 2 × 2 km quadrat. Results, Bird species richness showed a hump-shaped relationship with elevation. It increased with elevation from sea level (10,64 species per 2 × 2 km quadrat), peaked around 2000 m (43,76 species), and then decreased with elevation towards its minimum at the highest elevation. Road density and percentage of built area decreased with elevation, and NDVI showed a hump-shaped relationship with elevation and inverse relationships with road density and percentage of built area. BSR increased with NDVI and decreased with road density and percentage of built area. Linear and cubic terms of elevation together explained 31.3% of the variance in BSR, and road density explained additional 3.4%. The explanatory power of NDVI on BSR was insignificant after the effects of elevation and road density had been justified. Main conclusions, We argue that urbanization plays an important role in the BSR of Taiwan. Urbanization might indirectly decrease BSR through decreasing primary productivity and therefore change the hypothetical inverse relationship between BSR and elevation into a hump-shaped relationship. We also propose a time hypothesis that the biotic communities in the mid-elevation zone of Taiwan had relatively longer periods of existence during the Pleistocene glacial cycles, which might be one underlying process of the observed hump-shaped relationship between species diversity and elevation. [source]


Reducing morphological variability of the cervical carotid artery in serial magnetic resonance imaging using a head and neck immobilization device

JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 1 2008
Brian E. Chapman PhD
Abstract Purpose To evaluate how well a head and neck immobilization device performed in reducing lumen morphology variability in repeated MR imaging of the carotid artery. Materials and Methods Quantitative measures of lumen and plaque characteristics may be important for longitudinal management of carotid atherosclerotic disease. However, quantitative measurements of the carotid artery are limited by their dependence on patient positioning, which can be quite variable. We created a head and neck immobilization device to reduce the variability of patient positioning during MR imaging of the carotid artery. In this article we describe the design and use of the immobilization device and assess how well its use reduced variability in vascular orientation and measurements of the carotid lumen cross-sectional area. Evaluation was based on 15 subjects who were repeatedly imaged without the immobilization device and 14 subjects who were repeatedly imaged with the device. Results Use of the immobilization device decreased the orientation variability from 9.1° to 5.3° (P = 0.0006) and the variability (defined as the standard deviation divided by the mean) of the cross-sectional area decreased from 0.24 to 0.18 (P = 0.04). Conclusion Using the immobilization device effectively reduces variability in repeated imaging of the carotid arteries. J. Magn. Reson. Imaging 2008;28:258,262. © 2008 Wiley-Liss, Inc. [source]


Effects of Dry Grinding on the Structural Changes of Kaolinite Powders

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 7 2000
Pedro J. Sánchez-Soto
The present study examined the effects of dry grinding, using ball-milling, on the structure of reference well-crystallized (KGa-1) and poorly crystallized (KGa-2) kaolinite powders from Georgia. Grinding produced a strong structural alteration, mainly along the c axis, resulting in disorder and total degradation of the crystal structure of the kaolinite and the formation of an amorphous product. The surface area increased with grinding time, mainly in KGa-2 (maximum value 50.27 m2/g), a result associated with particle-size reduction. These particles became more agglomerated with grinding, and the surface area decreased after 30 min, as confirmed by scanning electron microscopy and particle-size-distribution analysis. There was a limit to particle-size reduction with grinding time. When grinding time was increased, the original endothermic differential thermal analysis (DTA) effects of dehydroxylation in both samples shifted to lower temperatures, decreased in intensity, then disappeared completely after 120 min of grinding. The temperature of the characteristic first exothermic effect shifted slightly to lower temperatures with grinding, although the DTA effects did not increase with grinding time in either kaolinite sample, at least up to 325 min. The amorphous, mechanically activated kaolinite converted into low-crystalline mullite nuclei at a lower temperature than did the unground samples, as deduced by thermal and X-ray observations. This effect was especially important for the KGa-2 sample. Grinding did not seem to influence the formation of silicon-aluminum spinel from kaolinite. The present results may explain why ground kaolinite samples prepared via different routes,e.g., with differences in grinding,behave differently during high-temperature transformations, as reported in the related literature. [source]


Prymnesium parvum: The Norwegian Experience,

JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 1 2010
Torbjørn M. Johnsen
Johnsen, Torbjørn M., Wenche Eikrem, Christine D. Olseng, Knut E. Tollefsen, and Vilhelm Bjerknes, 2010. Prymnesium parvum: The Norwegian Experience. Journal of the American Water Resources Association (JAWRA) 46(1):6-13. DOI: 10.1111/j.1752-1688.2009.00386.x Abstract:, In Norwegian waters, Prymnesium parvum has been reported from Oslofjorden in the south to Spitzbergen in the north. However, blooms of P. parvum have only been reported from the Sandsfjorden system in Ryfylke, Western Norway where the salinity of the permanent brackish layer (2-5 m) typically is in the range of 4-7 psu during the summer months. The first bloom on record occurred in 1989, and it killed 750 metric tons of caged salmon and trout which was a significant economic loss to the fish farming industry. Toxic blooms occurred as well in subsequent years and the number of fish farms in the area decreased considerably as did the occurrence of P. parvum. In 2005, fish farming was reintroduced to the area and again, in 2007 a toxic bloom of P. parvum killed 135 metric tons of caged fish. The Norwegian Institute for Water Research has, in collaboration with "Erfjord Stamfisk" fish farm, set up a monitoring program that includes light microscopy cell counts of Prymnesium, water quality measurements, and observation of the caged fish. A submergible fish net was mounted over the fish pens and during the toxic outbreak of P. parvum in July-August 2007, which was as previous years confined to the upper brackish water layer, the fish nets were lowered to 10 m depths below the surface and fish feeding was temporarily stopped. Despite substantial weight loss, the fish survived the toxic bloom and the economic loss was minimal. Monitoring of P. parvum bloom dynamics in 2007 revealed that populations were initially dominated by the nonmotile forms which were gradually replaced by the flagellated forms. Toxicity was observed when the flagellated cells dominated populations in the summer. Chrysochromulina, solitary small Chaetoceros species, and small centric diatoms co-existed with P. parvum during the monitoring period (June-October). [source]


In Vivo Optical Analysis of Quantitative Changes in Collagen and Elastin During Arterial Remodeling,

PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 2 2005
Alexander Christov
ABSTRACT Altered collagen and elastin content correlates closely with remodeling of the arterial wall after injury. Optical analytical approaches have been shown to detect qualitative changes in plaque composition, but the capacity for detection of quantitative changes in arterial collagen and elastin content in vivo is not known. We have assessed fluorescence spectroscopy for detection of quantitative changes in arterial composition in situ, in rabbit models of angioplasty and stent implant. Fluorescence emission intensity (FEI) recorded at sites remote from the primary implant site was correlated with immunohistochemical (IH) analysis and extracted elastin and collagen. FEI was significantly decreased (P < 0.05) after treatment with anti-inflammatory agents, and plaque area decreased on comparison with saline-treated rabbits after stent implant or angioplasty (P, 0.013). Excellent correlations for FEI with elastin and collagen I, III and IV content measured by IH (R2, 0.961) analysis were detected by multiple regression (MR) analysis. Good correlations also were found for FEI with elastin and collagen measured by high-performance liquid chromatography; MR analysis provided highly predictive values for collagen and elastin (R2, 0.994). Fluorescence spectroscopic analysis detects quantitative compositional changes in arterial connective tissue in vivo, demonstrating changes at sites remote from primary angioplasty and stent implant sites. [source]


Adjustment of leaf photosynthesis to shade in a natural canopy: reallocation of nitrogen

PLANT CELL & ENVIRONMENT, Issue 3 2005
H. EICHELMANN
ABSTRACT The present study was performed to investigate the adjustment of the constituents of the light and dark reactions of photosynthesis to the natural growth irradiance in the leaves of an overstorey species, Betula pendula Roth, a subcanopy species Tilia cordata P. Mill., and a herb Solidago virgaurea L. growing in a natural plant community in Järvselja, Estonia. Shoots were collected from the site and properties of individual leaves were measured in a laboratory, by applying a routine of kinetic gas exchange and optical measurements that revealed photosystem II (PSII), photosystem I (PSI), and cytochrome b6f densities per leaf area and the distribution of excitation (or chlorophyll, Chl) between the two photosystems. In parallel, N, Chl and ribulose-bisphosphate carboxylase-oxygenase (Rubisco) content was measured from the same leaves. The amount of N in photosynthetic proteins was calculated from the measured contents of the components of the photosynthetic machinery. Non-photosynthetic N was found as the residual of the budget. Growth in shade resulted in the decrease of leaf dry mass to a half of the DW in sun leaves in each species, but the total variation, from the top to the bottom of the canopy, was larger. Through the whole cross-section of the canopy, leaf dry weight (DW) and Rubisco content per area decreased by a factor of four, N content by a factor of three, but Chl content only by a factor of 1.7. PSII density decreased by a factor of 1.9, but PSI density by a factor of 3.2. The density of PSI adjusted to shade to a greater extent than the density of PSII. In shade, the distribution of N between the components of the photosynthetic machinery was shifted toward light-harvesting proteins at the expense of Rubisco. Non-photosynthetic N decreased the most substantially, from 54% in the sun leaves of B. pendula to 11% in the shade leaves of T. cordata. It is concluded that the redistribution of N toward light-harvesting Chl proteins in shade is not sufficient to keep the excitation rate of a PSII centre invariant. Contrary to PSII, the density of PSI , the photosystem that is in immediate contact with the carbon assimilation system , shade-adjusts almost proportionally with the latter, whereas its Chl antenna correspondingly increases. Even under N deficiency, a likely condition in the natural plant community, a substantial part of N is stored in non-photosynthetic proteins under abundant irradiation, but much less under limiting irradiation. At least in trees the general sequence of down-regulation due to shade adjustment is the following: (1) non-protein cell structures and non-photosynthetic proteins; (2) carbon assimilation proteins; (3) light reaction centre proteins, first PSI; and (4) chlorophyll-binding proteins. [source]


Evaluation of anti-wrinkle effects of a novel cosmetic containing retinol using the guideline of the Japan Cosmetic Industry Association

THE JOURNAL OF DERMATOLOGY, Issue 11 2009
Akira KAWADA
Abstract Retinol is known to be effective in the treatment of sallowness, wrinkling, red blotchiness and hyperpigmented spots in aging skin. In this study, we have evaluated the anti-wrinkle effects of a new cosmetic containing retinol. An open study was performed in 30 healthy Japanese women who had wrinkles at the corners of the eyes. The tested lotion, Retin-OX+ (RoC SA, Colombes, France), was applied on wrinkles of one side of the face for 8 weeks, and not on the other site as a control. Anti-wrinkle effects were evaluated by two methods: (i) doctors' observation and photos based on the guideline of the Japan Cosmetic Industry Association; and (ii) the Robo Skin Analyzer. This lotion showed marked and moderate improvement in 34% of the subjects with a significant difference as compared with the control sites (P < 0.05). Moreover, the length and area decreased in the applied site more than the control site with a significant difference (P < 0.01). All the patients completed the study without significant adverse reactions. The tested lotion was well tolerated and may be an optional preparation for the treatment of wrinkles at the corner of the eyes. [source]


Forest landscape pattern in the KwaZulu,Natal midlands, South Africa: 50 years of change or stasis?

AUSTRAL ECOLOGY, Issue 6 2004
MICHAEL J. LAWES
Abstract Understanding patterns and processes of habitat change is essential for managing and conserving forest fragments in anthropogenically altered landscapes. Digitized aerial photographs from 1944 and 1996 were examined for changes to the indigenous forest landscape in the Karkloof-Balgowan archipelago in KwaZulu,Natal, South Africa. Attributes relating to proximate land-use, patch shape, isolation and position in the landscape were used to determine putative causes of forest change. The total change in forest area was ,5.7% (forest covered 6739 ha in 1996). This is contrasted with previous reports for the period 1880,1940 that estimated change in total forest area of up to ,80%. Attrition was the predominant process of forest transformation between 1944 and 1996. Despite little overall change in forest area, 786 mostly small (<0.5 ha) forest patches were lost from the landscape, leaving 1277 forest patches in 1996. An increase in patch isolation, but no change in patch cohesion accompanied the changes in forest area. Ignoring patches that were eliminated, 514 patches decreased in area. This was partly a function of patch size, but the conversion of natural grassland to commercial plantation forestry in the matrix also influenced forest decline. Their small size and irregular shape caused forest patches in the region to be vulnerable to edge effects. Core area declined in a negative exponential way with increasing edge width and the total area of edge habitat exceeded that of core habitat at an edge width of only 50 m. Nevertheless, total core area decreased by only 2% (65 ha) between 1944 and 1996 because most of the eliminated patches were small and contained no core area. The large Karkloof forest (1649 ha) is a conservation priority for forest interior species, but the ecological role and biodiversity value of small forest patches should not be overlooked. [source]


Annual Rainfall and Seasonality Predict Pan-tropical Patterns of Liana Density and Basal Area

BIOTROPICA, Issue 3 2010
Saara J. DeWalt
ABSTRACT We test the hypotheses proposed by Gentry and Schnitzer that liana density and basal area in tropical forests vary negatively with mean annual precipitation (MAP) and positively with seasonality. Previous studies correlating liana abundance with these climatic variables have produced conflicting results, warranting a new analysis of drivers of liana abundance based on a different dataset. We compiled a pan-tropical dataset containing 28,953 lianas (,2.5 cm diam.) from studies conducted at 13 Neotropical and 11 Paleotropical dry to wet lowland tropical forests. The ranges in MAP and dry season length (DSL) (number of months with mean rainfall <100 mm) represented by these datasets were 860,7250 mm/yr and 0,7 mo, respectively. Pan-tropically, liana density and basal area decreased significantly with increasing annual rainfall and increased with increasing DSL, supporting the hypotheses of Gentry and Schnitzer. Our results suggest that much of the variation in liana density and basal area in the tropics can be accounted for by the relatively simple metrics of MAP and DSL. Abstract in Spanish is available at http://www.blackwell-synergy.com/loi/btp [source]


Fruit, Minerals, and Forest Elephant Trails: Do All Roads Lead to Rome?

BIOTROPICA, Issue 3 2004
Stephen Blake
ABSTRACT Tropical forests are among the most heterogeneous environments on earth, and food resources for many animals are patchy both in time and space. In Africa's equatorial forest, permanent trails created and maintained by forest elephants are conspicuous features. Trails may be several meters wide and continue for tens of kilometers. Speculation on which resources determine the distribution of trails has identified fruit, browse, and mineral deposits as candidates. In this study, the relationships between these habitat variables and elephant trails were investigated. The size of individual trails and the density of the trail system increased dramatically with proximity to mineral deposits. Fruit tree basal area decreased with perpendicular distance from trails, while that of non-fruit trees did not. Fruit tree abundance and basal area were significantly higher on trail intersections than random sites and increased with intersection size. No relationship was found between monocotyledon browse abundance and elephant trail system characteristics. Clumped resources, which are at least partially reliable, provide a high nutritional payback, and are not rapidly depleted and can thus be visited repeatedly, appear to influence permanent trail formation by forest elephants. Permanent trails may allow naive individuals or those with imperfect knowledge to locate and acquire important resources. [source]


Therapeutic effect of subconjunctival injection of bevacizumab in the treatment of corneal neovascularization

ACTA OPHTHALMOLOGICA, Issue 6 2009
In-Cheon You
Abstract. Purpose:, To investigate the efficacy of subconjunctival injection of bevacizumab in the treatment of patients with corneal neovascularization. Methods:, Twenty-nine eyes of 29 patients with corneal neovascularization were treated with subconjunctival injection [1.25 mg/0.05 ml (seven eyes), 2.5 mg/0.1 ml (15 eyes) and 5.0 mg/0.2 ml (seven eyes)] of bevacizumab. Best-corrected visual acuity, intraocular pressure and area of corneal neovascularization were measured before injection and at 1 week, 1 month and 3 months after treatment. Results:, At 1 week, the mean neovascularized corneal area decreased significantly to 85.5 ± 18.0% (p = 0.01) in the eyes treated with 2.5 mg bevacizumab and to 73.1 ± 23.4% (p = 0.02) in the eyes treated with 5.0 mg bevacizumab. At 3 months, the mean neovascularized corneal area was 93.6 ± 10.6% (p = 0.10 compared to baseline; p < 0.01 compared to 1 week) in the eyes treated with 2.5 mg bevacizumab and 83.3 ± 25.8% (p = 0.03 compared to baseline; p = 0.02 compared to 1 week) in the eyes treated with 5.0 mg bevacizumab. However, there were no significant changes in the areas of the eyes injected with 1.25 mg bevacizumab. Conclusion:, Subconjunctival injection of bevacizumab can partially reduce corneal neovascularization in the short term, and the efficacy of this treatment correlates with the injection dose. [source]


Elevation and forest clearing effects on foraging differ between surface , and subterranean , foraging army ants (Formicidae: Ecitoninae)

JOURNAL OF ANIMAL ECOLOGY, Issue 1 2009
Anjali Kumar
Summary 1Forest fragmentation often results in a matrix of open areas mixed with patches of forest. Both biotic and abiotic factors can affect consumer species' ability to utilize the altered habitat, especially for species that range over large areas searching for prey. 2Army ants (Formicidae: Ecitoninae) are highly mobile top predators in terrestrial Neotropical ecosystems. Army ant foraging behaviour is influenced by forest clearing at lowland sites, and clearing can reduce army ant population persistence. 3Because high temperatures are implicated in hindering above-ground army ant foraging, we predicted that forest clearing effects on army ant foraging would be reduced at higher (cooler) elevations in montane forest. We also predicted that subterranean foraging, employed by some army ant species, would buffer them from the negative effects of forest clearing. 4We quantified the foraging rates of above-ground and underground foraging army ants at eight sites along an elevational gradient from 1090 to 1540 m a.s.l. We asked whether these two foraging strategies cause a difference in the ability of army ants to forage in open matrix areas relative to elevationally matched forested habitats, and whether elevation predicts open area vs. forest foraging rate differences. 5As predicted, army ants that forage above-ground had lower foraging rates in open areas, but the open area vs. forest difference declined with elevation. In contrast, underground foragers were not affected by habitat type, and underground foraging rates increased with elevation. Ground surface temperatures were higher in open areas than forested areas. Temperatures declined with elevation, and temperature differences between open and forested areas decreased with elevation. 6We conclude that army ants that forage above-ground may be restricted to forested areas due to a thermal tolerance threshold, but that they are released from this limitation at higher elevations. We further suggest that underground foraging permits some army ants to persist within modified landscapes. Our findings have implications for the effects of habitat modification and climate change on these top predators. [source]


Thoroughness of skin examination by melanoma patients: Influence of age, sex and partner

AUSTRALASIAN JOURNAL OF DERMATOLOGY, Issue 3 2009
Susan L Boone
ABSTRACT The aim of this study was to determine the thoroughness of deliberate skin examination by people with a history of melanoma. Patients were randomized into one of two conditions: either to receive the brief educational and skills training intervention alone or as a couple with their spouse or cohabiting partner. Subjects recorded concerning lesions on body maps. At the 4-month visit, a total body skin examination was performed by a dermatologist blinded to the subjects' condition and to their recorded responses. The skin surface was divided according to the region's visibility during skin self-examination and sexual connotations: visible/not sexually sensitive, non-visible/not sexually sensitive and sexually sensitive. The primary point of comparison was missed lesions, defined as the difference between lesions recorded by the subjects and their partners and those recorded by the dermatologist. Among 130 participants, 56 subjects reported partner assistance while performing SSE. Participants missed more lesions in sexually sensitive areas than in the other regions. With the increasing age of the patient, the number of missed lesions in non-visible/not sexually sensitive and sexually sensitive areas decreased. Male patients assisted by female partners missed fewer lesions in all three regions than female patients assisted by male partners. In easily visible areas, male patients missed significantly fewer lesions than female patients (P = 0.01). Older couples performed more thorough partner-assisted skin examinations in non-visible and sexually sensitive areas than younger couples. Male patients who were assisted by female partners performed more thorough partner-assisted skin examinations than female patients assisted by male partners. [source]


Prevalence of Japanese cedar pollinosis in Tokyo: a survey conducted by the Tokyo Metropolitan Government

CLINICAL & EXPERIMENTAL ALLERGY REVIEWS, Issue 1 2010
S. Nishihata
Summary In 2006, a survey was conducted to estimate the prevalence of Japanese cedar pollinosis in three target areas in Tokyo, namely Akiruno-shi, Chofu-shi, and Ota-ku; this survey was similar to two surveys conducted previously, in 1983,1987 (first survey) and 1996 (second survey). In the most recent survey, the overall prevalence of Japanese cedar pollinosis in Tokyo, except the islands of Tokyo, was estimated as 28.2%. This prevalence rate exceeds that estimated by the first and second surveys by 18.2 and 8.8 percentage points, respectively. The prevalence of Japanese cedar pollinosis in the three survey target areas increased by 2.3,10.8 percentage points vs. the rates obtained in the second survey. Furthermore, differences among the prevalence rates in the three areas decreased. Compared with the results obtained in the second survey, increases in the prevalence rate were noted in all age groups other than in people aged 30,44 years. In particular, the prevalence rate in children aged 0,14 years increased markedly, showing a threefold increase. The prevalence rate exceeded 30% in all age groups between 15 and 59 years. [source]