1,413 research outputs found
Habitat complexity and its use correlate with soil-transmitted helminthiasis in two social groups of Macaca maura (H.R. Schinz, 1825), endangered primates endemic to Sulawesi island, Indonesia
No full textSulawesi endemic Macaca maura is included in the IUCN Red List as Endangered due to
anthropogenic disturbance and fragmentation of its habitat. Residual populations have a scattered
distribution in the karst forests of south Sulawesi. Here the dissolution of limestone layers
has created a multi-level landscape hardly accessible for ground predators and humans. In this
study, we aimed to obtain better knowledge on the ecological flexibility of M. maura in the use
of such a complex habitat, and its consequences on health status. Since all data published on M.
maura were obtained from a single group (group B), an additional group (G) was habituated to
human presence. We analysed 50 vegetation plots (10 × 20 metres) to discriminate structural
features in terms of feeding options (e.g. key food species diversity, density and DBH) and anthropogenic
disturbance (e.g. human trails and solid litter). We then correlated these data with
habitat use and helminth infection. We collected 74 faecal samples from 18 different adult individuals
belonging to both groups. Vegetation analysis suggested that there were 2 suitable habitats:
a Ground Forest (e.g. higher abundance of key food species) and a Karst Tower Forest (e.g.
lower presence of human trails and solid litter). Gastrointestinal investigation revealed a positive
correlation between the prevalence of Trichuris sp. and time devoted to ground food-related activities
in all individuals (Spearman correlation, rs = 0.665, p = 0.003). Moreover, behavioural
data confirmed that group B, the larger study group of the area, spent most of its activity time in
the Ground Forest (N group B = 33 ± 1; N group G = 18 ± 1; χ 2
= 134.30, d.f. = 1, p < 0.001). Since resource
availability and predation risk can influence foraging decisions and, ultimately, space use,
the “group size effect” might explain the significantly higher proportion of time spent by group
B in the Ground Forest. Consequently, due to the Trichuris faecal-oral contamination life-cycle,
the chance of infecting individuals based on their feeding habits might be described according to
the “soil-transmitted helminthiasis hypothesis
EVALUATION OF OLIGOMER FOULING RESISTANCE IN A PLATEHEAT EXCHANGER FOR HEAT RECOVERY FROMPOLYESTER DYEING WASTEWATER
No full textThird-line chemotherapy with mitomycin C and lonidamine in advanced bladder cancer. Partial response in a patient with skin and lung metastases.
No full textSkin metastases from transitional cell carcinoma are quite rare. The present case report describes the results of a combination of mitomycin C and lonidamine administered as third-line chemotherapy in a patient with pulmonary and skin involvement from bladder cancer. The partial response obtained suggests that further testing should be carried out on the activity of this association in a second-line approach
Conformational studies on a synthetic C-terminal fragment of the alpha subunit of G(S) proteins.
No full textIt has recently been reported that synthetic peptides corresponding to the C-terminal sequence of G, can be used to study the molecular mechanisms of interaction between this protein and G protein coupled receptors (Hamm et al., Science, 1988, Vol. 241, pp. 832-835). A conformational analysis on a 11 amino acids peptide from the GS C-terminus, GS(384-394) (H-QRMHLRQYELL-OH), was performed by nmr spectroscopy and molecular modeling methods. Two-dimensional nmr spectra, recorded in hexafluoroacetone/water, a mixture with structure stabilizing properties, showed an unusually high number of nuclear Overhauser effects, forming significative pattern to the drawing of a secondary structure. Conformations consistent with experimental NOE distances were obtained through molecular dynamics and energy minimization methods. These calculations yielded two stable conformers corresponding to an -turn and a type III -turn involving the last five C-terminal residues. Interestingly, the -turn conformation was found to overlap with good agreement the crystallographic structure of the same fragment in the GS protein
Rhynchocyon udzungwensis Rathbun & Rovero 2008
No full text5. Gray-faced Sengi Rhynchocyon udzungwensis French: Sengi a face grise / German: Graugesicht-Risselhlindchen / Spanish: Sengi de cara gris Other common names: Gray-faced Elephant-shrew, Grey-faced Sengi, Grey-faced Elephant-shrew Taxonomy. Rhynchocyon udzungwensis Rathbun & Rovero, 2008, “ Vikongwa River Valley, Ndundulu Forest, West Kilombero Scarp Forest Reserve, Udzungwa Mountains, Iringa Region, Tanzania [7°48.269’S, 36°30.355’E (Arc 1960 datum) |, at 1350 m a.s.l.” This species is monotypic. Distribution. Udzungwa Mts of Eastern Arc Mts, C Tanzania. Descriptive notes. Head-body 297-318 mm, tail 239-262 mm, ear wy mm, hindfoot 79-88 mm; weight 658-750 g. There is no evidence of sexual dimorphism in body size. Tail of the Gray-faced Sengi is ¢.80% of head-body length and is proximally thick and distally tapered. Tail skin is black on dorsal side and dark brown below, with subterminal white, 4-6cm band; tail hair is short, sparse, and same color as skin. Pinnae are nearly hairless, with black to dark brown skin. Hairs on top and sides of face have black bases and cream or white tips giving face a gray appearance, which is diagnostic. Hair behind ears and on shoulders is rufous-yellow, transitions to rufous on dorsum and orange-rufous on sides and becomes black near rump. Hair on venter is pale yellow to cream. Skin on snoutis black and nearly hairless. Snout is exceptionally long and flexible. Dental formulais10-1/3,C1/1,P 4/4, M 2/2 (x2) = 34-36. Upper canines are relatively large, and males have longer upper canines than females. Although not yet reported, presence of diminutive upper incisor presumably is probably variable. Palatal foramina are absent. Postorbital processes are present. Females have two posterior, two intermediate, and no anterior nipples; males have no nipples. Four digits are present on each manus and pes; pollex and hallux are absent. Fifth manual digit is relatively short and has only two phalanges. Post-anal gland is well developed, and pectoral gland is absent. Karyotype is unknown. Habitat. Montane forests (closed canopies and dense leaflitter always present) at elevations of 1000-2300 m. In the northern Mwanihana Forest, some Gray-faced Sengis occur in deciduous to semi-deciduous lowland habitat, which might be suboptimal. Food and Feeding. Diet of the Gray-faced Sengi is probably strictly composed of invertebrates and mostly arthropods, based on similar habitats and shared biology with other species of Rhynchocyon. Breeding. There is no information available for this species, but the Gray-faced Sengi is probably similar to the Black-and-rufous Sengi (R. petersi). Activity patterns. Gray-faced Sengis are fully terrestrial and exclusively diurnal. Nesting is probably similar to that of other species of Rhynchocyon. Each member of a male—female pair probably spends most ofits time independently. Movements, Home range and Social organization. There is no information available for this species, but the Gray-faced Sengi is probably similar to other species of Rhynchocyon. Status and Conservation. Classified as Vulnerable on The IUCN Red List. The Grayfaced Sengi occurs only in Ndundulu-Luhomero and Mwanihana forests, which are prone to stochastic drought-driven and human-induced fires. Its area of occupancy is estimated to be only 390 km?, and its population trend is unknown. Bibliography. Carlen et al. (2017), Corbet & Hanks (1968), Dollman (1912), Evans (1942), Lawson et al. (2013), Olbricht & Stanley (2009), Rathbun (2009, 2013c), Rovero & Rathbun (2015), Rovero et al. (2008).Published as part of Russell A. Mittermeier & Don E. Wilson, 2018, Macroscelididae, pp. 206-234 in Handbook of the Mammals of the World – Volume 8 Insectivores, Sloths and Colugos, Barcelona :Lynx Edicions on page 228, DOI: 10.5281/zenodo.664656
Density estimation of the endangered Udzungwa red colobus (Procolobus gordonorum) and other arboreal primates in the Udzungwa Mountains using systematic distance sampling
No full textEstimates of population density and abundance are essential for the assess- ment of nonhuman primate conservation status, especially in view of increasing threats. We undertook the most extensive systematic primate survey yet of the Udzungwa Mountains of Tanzania, an outstanding region for primate endemism and conservation in Africa. We used distance sampling to survey three arboreal monkey species, including the endangered and endemic Udzungwa red colobus (Procolobus gordonorum). Overall, we encountered 306 primate clusters over 287 km walked along 162 line transects. We found the lowest cluster densities for both red colobus and Angolan colobus (Colobus angolensis; 0.8 clusters/km2) in the least protected forest (Uzungwa Scarp Forest Reserve, US), while we found the highest densities (3.2 and 2.6 clusters/km2 for red colobus; 3.2 and 2.7 clusters/km2for Angolan colobus) in two large and protected forests in the national park. Unexpectedly, Magombera, a small forest surrounded by plantations, had the highest densities of red colobus (5.0 clusters/km2), most likely a saturation effect due to the rapid shrinking of the forest. In contrast, Sykes’ monkey (Cercopithecus mitis monoides/moloneyi) had more similar densities across forests (3.1–6.6 clusters/km2), including US, suggesting greater resilience to disturbance in this species. For the endemic red colobus monkey, we estimated an abundance of 45–50,000 individuals across all forests, representing ca. 80% of the global population. Though this is a relatively high abundance, the increasing threats in some of the Udzungwa forests are of continued concern for the long-term survival of red colobus and other primates in the are
A Gα(s) carboxyl-terminal peptide prevents G(s) activation by the A(2A) adenosine receptor
No full textThe molecular mechanisms of interaction between G(s) and the A(2A) adenosine receptor were investigated using synthetic peptides corresponding to various segments of the Galpha(s) carboxyl terminus. Synthetic peptides were tested for their ability to modulate binding of a selective radiolabeled agonist, [(3)H]2-[4-(2-carboxyethyl)phenylethylamino]-5'-N-ethylcarboxam idoade nosine ([(3)H]CGS21680), to A(2A) adenosine receptors in rat striatal membranes. The Galpha(s) peptides stimulated specific binding both in the presence and absence of 100 microM guanosine-5'-O-(3-thiotriphosphate) (GTPgammaS). Three peptides, Galpha(s)(378-394)C(379)A, Galpha(s)(376-394)C(379)A, and Galpha(s)(374-394)C(379)A, were the most effective. In the presence of GTPgammaS, peptide Galpha(s)(374-394)C(379)A increased specific binding in a dose-dependent fashion. However, the peptide did not stabilize the high-affinity state of the A(2A) adenosine receptor for [(3)H]CGS21680. Binding assays with a radiolabeled selective antagonist, [(3)H]5-amino-7-(2-phenylethyl)-2-(2-furyl)pyrazolo[4, 3-e]-1,2,4-triazolo[1,5-c]pyrimidine ([(3)H]SCH58261), showed that the addition of the Galpha(s) peptide modified the slope of the 5'-N-ethylcarboxamidoadenosine (NECA) competition curve, suggesting modulation of receptor affinity states. In the presence of GTPgammaS, the displacement curve was right-shifted, whereas the addition of Galpha(s)(374-394)C(379)A caused a partial left-shift. Both curves were fitted by one-site models. This same Galpha(s) peptide was also able to disrupt G(s)-coupled signal transduction as indicated by inhibition of the A(2A) receptor-stimulated adenylyl cyclase activity without affecting either basal or forskolin-stimulated enzymatic activity in the same membrane preparations. Shorter peptides from Galpha(s) and Galpha(i1/2) carboxyl termini were not effective. NMR spectroscopy showed the strong propensity of peptide Galpha(s)(374-394)C(379)A to assume a compact carboxyl-terminal alpha-helical conformation in solution. Overall, our results point out the conformation requirement of Galpha(s) carboxyl-terminal peptides to modulate agonist binding to rat A(2A) adenosine receptors and disrupt signal transduction
Conformational studies on a synthetic C-terminal fragment of the alpha subunit of G(S) proteins.
No full textIt has recently been reported that synthetic peptides corresponding to the C-terminal sequence of Gα, can be used to study the molecular mechanisms of interaction between this protein and G protein coupled receptors (Hamm et al., Science, 1988, Vol. 241, pp. 832-835). A conformational analysis on a 11 amino acids peptide from the Gα(s) C-terminus, Gα(s)(384-394) (H- QRMHLRQYELL-OH), was performed by nmr spectroscopy and molecular modeling methods. Two-dimensional nmr spectra, recorded in hexafluoroacetone/water, a mixture with structure stabilizing properties, showed an unusually high number of nuclear Overhauser effects, forming significative pattern to the drawing of a secondary structure. Conformations consistent with experimental NOE distances were obtained through molecular dynamics and energy minimization methods. These calculations yielded two stable conformers corresponding to an α-turn and a type III β-turn involving the last five C- terminal residues. Interestingly, the α-turn conformation was found to overlap with good agreement the crystallographic structure of the same fragment in the Gα(s) protein. (C) 2000 John Wiley and Sons, Inc.
It has recently been reported that synthetic peptides corresponding to the C-terminal sequence of Gα, can be used to study the molecular mechanisms of interaction between this protein and G protein coupled receptors. A conformational analysis on a 11 amino acids peptides from the GαS C-terminus, GαS(384-394) (H-QRMHLRQYELL-OH), was performed by nmr spectroscopy and molecular modeling methods. Two-dimensional nmr spectra, recorded in hexafluoroacetone/water, a mixture with structure stabilizing properties, showed an unusually high number of nuclear Overhauser effects, forming significative pattern to the drawing of a secondary structure. Conformations consistent with experimental NOE distances were obtained through molecular dynamics and energy minimization methods. These calculations yielded two stable conformers corresponding to an α-turn and a type III β-turn involving the last five C-terminal residues. Interestingly the α-turn conformation was found to overlap with good agreement the crystallographic structure of the same fragment in the GαS protein
A structure-activity study of a C-terminal endothelin analogue
No full textWe report a structure-activity study of an endothelin (ET) analogue, obtained by introduction of a non-aminoacidic portion on the C-terminal ET pentapeptide. The peptidic moiety was modified with systematic replacement of each residue by alanine (Ala scan); further modifications were performed at the C-terminus. The biological activity was analyzed at both ETA and ETU receptor subtypes, showing that the two C-terminal residues (Ile-Trp) are very important for the activity. On the contrary, the aminoacidic central portion of the molecule appears to be much more tolerant toward modifications
- …
