The role of spatial scale in understanding responses of medium-sized carnivores to forest fragmentation

1996 ◽  
Vol 74 (11) ◽  
pp. 2070-2079 ◽  
Author(s):  
James D. Oehler ◽  
John A. Litvaitis
Keyword(s):  
Spatial Scale ◽  
Habitat Diversity ◽  
Generalist Predators ◽  
Wild Canids ◽  
Close Proximity ◽  
Proximate Factor ◽  
Agricultural Areas ◽  
Free Ranging ◽  
Felis Domesticus

Increased predation has been suggested as a proximate factor causing the decline of vertebrate diversity in many human-altered landscapes. Previous studies on this topic have provided conflicting results, perhaps as a consequence of the limited spatial scale used in these investigations. We incorporated a multiscaled approach (using site, plot (1.44 km2), and landscape (54 km2)) to investigate the distribution of activity of medium-sized carnivores relative to habitat edges and the numeric responses of these predators to habitat diversity. Among the taxa surveyed, raccoons (Procyon lotor) did not show an affinity for habitat edges at any spatial scale. However, raccoons were more abundant in landscapes characterized by a diversity of cover types. Free-ranging domestic dogs (Canis familiaris) and cats (Felis domesticus) did not respond to the proximity of habitat edges in summer but showed a strong affinity for edge habitats (especially those associated with human dwellings) during winter. Wild canids (Vulpes vulpes and Canis latrans) also selected sites in close proximity to edges in winter and were more abundant in diverse landscapes. Although human-dominated habitats (agricultural areas, grass–brushland, and developed sites) represented only 7–27% of the three landscapes studied, populations of generalist predators (raccoons and wild canids) increased as landscapes became more diverse. As a result, even moderate levels of habitat fragmentation may elevate predation rates and subsequently alter the composition of prey communities.

Rickettsia parkeri in free-ranging wild canids from Brazilian Pampa

2017 ◽  
Vol 65 (2) ◽  
pp. e224-e230 ◽  
Author(s):  
B. Dall'Agnol ◽  
U. A. Souza ◽  
B. Weck ◽  
T. C. Trigo ◽  
M. M. A. Jardim ◽  
...  
Keyword(s):  
Rickettsia Parkeri ◽  
Wild Canids ◽  
Free Ranging

scholarly journals Translationally Repressed mRNA Transiently Cycles through Stress Granules during Stress

2008 ◽  
Vol 19 (10) ◽  
pp. 4469-4479 ◽  
Author(s):  
Stephanie Mollet ◽  
Nicolas Cougot ◽  
Ania Wilczynska ◽  
François Dautry ◽  
Michel Kress ◽  
...  
Keyword(s):  
Residence Time ◽  
Kinetic Data ◽  
Stress Granules ◽  
Stress Relief ◽  
Mrna Degradation ◽  
Stress Granule ◽  
Storage Site ◽  
Direct Role ◽  
Close Proximity

In mammals, repression of translation during stress is associated with the assembly of stress granules in the cytoplasm, which contain a fraction of arrested mRNA and have been proposed to play a role in their storage. Because physical contacts are seen with GW bodies, which contain the mRNA degradation machinery, stress granules could also target arrested mRNA to degradation. Here we show that contacts between stress granules and GW bodies appear during stress-granule assembly and not after a movement of the two preassembled structures. Despite this close proximity, the GW body proteins, which in some conditions relocalize in stress granules, come from cytosol rather than from adjacent GW bodies. It was previously reported that several proteins actively traffic in and out of stress granules. Here we investigated the behavior of mRNAs. Their residence time in stress granules is brief, on the order of a minute, although stress granules persist over a few hours after stress relief. This short transit reflects rapid return to cytosol, rather than transfer to GW bodies for degradation. Accordingly, most arrested mRNAs are located outside stress granules. Overall, these kinetic data do not support a direct role of stress granules neither as storage site nor as intermediate location before degradation.

Transportation pathways of pesticides in two major watersheds of Istanbul, Turkey

2004 ◽  
Vol 49 (3) ◽  
pp. 165-172 ◽  
Author(s):  
M. Yazgan ◽  
A. Tanik
Keyword(s):  
Chemical Properties ◽  
Surface Flow ◽  
Priority List ◽  
Pesticide Pollution ◽  
Consumption Values ◽  
Annual Consumption ◽  
Agricultural Areas ◽  
Physical And Chemical ◽  
And Chemical Properties

The study covers the investigation of pesticides in terms of consumption, toxicological classification and various intrinsic physical and chemical properties like DT50, KOC, GUS, solubility that describe the important mechanisms prevailing in soil, namely persistence and mobility. These mechanisms help to estimate the transportation pathways of pesticides on soil till they reach the receiving water after being applied on land. Classification is done in three groups, those likely to appear in surface flow, those that appear in groundwater and those that present transient conditions. Such an approach that also takes into account toxicological levels and annual consumption values of pesticides will act as a tool to prepare the priority list of pesticides that need special care during their transportation. The fate of pesticides is a difficult task to solve, however, such a methodology, puts forth a rough estimate on their behavior in spite of uncertainties in many of the parameters describing mechanisms like persistence and mobility. The agricultural areas of two watersheds of Istanbul are selected as target areas to describe the approach, which is also checked with another approach estimating pesticide pollution potential that considers various other properties of pesticides. Almost similar findings are depicted with 85% proximity. The methodology presented in the paper illustrates and emphasizes the significant role of pesticide properties in determining their fate in soil after being applied.

scholarly journals Role of the gonadal vessels on the stone lodgment in the proximal ureter: Direct observation during laparoscopic ureterolithotomy

2018 ◽  
Vol 90 (3) ◽  
pp. 163-165
Author(s):  
Mohammad Hadi Radfar ◽  
Reza Valipour ◽  
Behzad Narouie ◽  
Mehdi Sotoudeh ◽  
Hamid Pakmanesh
Keyword(s):  
Direct Observation ◽  
Ureteral Stone ◽  
Ureteral Stenosis ◽  
Ureterovesical Junction ◽  
Gonadal Vein ◽  
Close Proximity ◽  
Proximal Ureter ◽  
Radiological Studies ◽  
Stone Passage

Introduction: Previous radiological studies revealed that stones lodge more frequently in the ureterovesical junction (UVJ) as well as the proximal ureter. Factors that prevent stone passage from the proximal ureter are not well studied. Aim: To explore the site of the lodged stones in the proximal ureter with direct observation during laparoscopic ureterolithotomy. Materials and methods: Between November 2014 and February 2015, we included 26 patients including 18 men and 8 women with stones larger than 10 millimeters in the proximal ureter who were candidate for laparoscopic ureterolithotomy. We prospectively recorded the site of the lodged stones in the ureter during laparoscopic ureterolithotomy in relation with the sites of ureteral stenosis as well as the gonadal vessels. Results: Among 26 patients with ureteral stone, in 19 cases stone was found close to the gonadal vein compared with seven cases that stone was in other locations of the ureter (p = 0.02). The characteristics of patients and stones were not different in cases that the stone was close to gonadal vessels compared with other locations. Conclusions: This study showed that most of the stones lodged in the proximal ureter were in close proximity with gonadal vessels. Gonadal vessels may be an extrinsic cause of ureteral narrowing.

scholarly journals Fungi associated to bark lesions of Eucalyptus globulus stems in plantations from Uruguay

2009 ◽  
Vol 33 (4) ◽  
pp. 591-597 ◽  
Author(s):  
Raquel Alonso ◽  
Susana Tiscornia ◽  
Acelino Couto Alfenas ◽  
Lina Bettucci
Keyword(s):  
Eucalyptus Globulus ◽  
Dominant Species ◽  
Wood Decay ◽  
Stem Bark ◽  
Fungal Species ◽  
West Region ◽  
Close Proximity ◽  
Experimental Inoculation ◽  
Penicillium Spp

Trees with stem bark lesions are frequently observed in Eucalyptus globulus Labill. plantations, particularly in the central west region of Uruguay. These lesions constitute a problem for trunk decortications at harvest and they also facilitate the access of fungi that could cause wood decay. Seven, three and oneyear-old plantations, located at three sites in close proximity were selected. Four types of trunk lesions were present in trees regardless the age of plantation and more than one type was found in each plantation. The aim of this study was to investigate the fungal composition associated with these lesions and compare them to healthy tissues and try to find out the origin of these symptoms. Another purpose was to elucidate the real role of the fungi considered pathogens by means of experimental inoculations. Segments from lesions and healthy tissues yielded 897 fungal isolates belonging to 32 taxa, 681 isolates from bark lesions and 216 from healthy tissues. Both healthy and symptomatic tissues showed similar fungal species composition, but with differences in frequencies of colonization. Cytospora eucalypticola Van der Westhuizen, Botryosphaeria spp., Pestalotiopsis guepinii (Desm.) Stey. and Penicillium spp. were the dominant species isolated. As symptoms were not reproduced after experimental inoculation with Botryosphaeria ribis Grossenb. & Duggar and B. eucalyptorum Crous, & M.J. Wingf, it could be suggested that these lesions were originated by unfavorable environmental conditions. The frost that occurred for several days out of season and flooding may have been involved in the development of bark lesion.

scholarly journals RNA binding to human METTL3-METTL14 restricts N6-deoxyadenosine methylation of DNA in vitro

2022 ◽  
Author(s):  
Shan Qi ◽  
Javier Mota ◽  
Siu-Hong Chan ◽  
Johanna Villarreal ◽  
Nan Dai ◽  
...  
Keyword(s):  
Binding Affinity ◽  
Rna Binding ◽  
Methyl Group ◽  
High Affinity ◽  
Methylation Of Dna ◽  
Dna And Rna ◽  
Close Proximity ◽  
Methylation Activity

Methyltransferase like-3 (METTL3) and METTL14 complex transfers a methyl group from S-adenosyl-L-methionine to N6 amino group of adenosine bases in RNA (m6A) and DNA (m6dA). Emerging evidence highlights a role of METTL3-METTL14 in the chromatin context, especially in processes where DNA and RNA are held in close proximity. However, a mechanistic framework about specificity for substrate RNA/DNA and their interrelationship remain unclear. By systematically studying methylation activity and binding affinity to a number of DNA and RNA oligos with different propensities to form inter- or intra-molecular duplexes or single-stranded molecules in vitro, we uncover an inverse relationship for substrate binding and methylation and show that METTL3-METTL14 preferentially catalyzes the formation of m6dA in single-stranded DNA (ssDNA), despite weaker binding affinity to DNA. In contrast, it binds structured RNAs with high affinity, but methylates the target adenosine in RNA (m6A) much less efficiently than it does in ssDNA. We also show that METTL3-METTL14-mediated methylation of DNA is largely restricted by structured RNA elements prevalent in long noncoding and other cellular RNAs.

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