1,671 research outputs found
The Effects of Roadways on the Spatial and Temporal Movement Patterns of Timber Rattlesnakes (Crotalus horridus)
Roadways are among the most widespread and disruptive anthropogenic land use features that influence the behavior and movement of wildlife. Negative impacts include vehicle-induced mortality, habitat destruction and fragmentation, and creating barriers to movement which can have far-reaching sub-lethal effects. In an effort to improve upon historical methods of evaluating the influence of prominent landscape features, such as roads, on the movement of small and secretive wildlife, we are using a novel integration of emerging spatial analyses and tri-axial accelerometry in Timber Rattlesnakes (Crotalus horridus) from central Georgia. We used dynamic Brownian Bridge Movement Models to estimate motion variance and utilization distributions (UDs) for individual rattlesnakes, and accelerometers simultaneously provide long-term and continuous activity budgets to quantify “real-time” temporal movement patterns. Relating these spatial and temporal metrics to the Mean Distance to Roadway (MDR) revealed no significant associations when considering the full sample. However, sub-setting the data by sex revealed a significant positive linear relationship in males between MDR and Distance Per Movement (DPM) and UDs. These preliminary results indicate that with decreasing distance to roads, males use less space and move shorter distances per movement (DPM), suggesting that roads might pose as a passive barrier to movement for males in our population. Interestingly, we also detected a significant negative linear relationship between MDR and mean Hours spent Moving per Day (HMD) by male rattlesnakes. Given that this opposing relationship between MDR and the spatial and temporal patterns of movement was not displayed by females, we suspect that males in close proximity to roads might be compensating for smaller home range sizes (and reduced overlap with females) by increasing activity (HMD) during the mating season (August-October) to elevate encounter frequencies with reproductive females. Increasing our sample size and duration of monitoring will help to refine these preliminary findings
How action structures time: About the perceived temporal order of action and predicted outcomes
Few ideas are as inexorable as the arrow of causation: causes must precede their effects. Explicit or implicit knowledge about this causal order permits humans and other animals to predict and control events in order to produce desired outcomes. The sense of agency is deeply linked with representation of causation, since it involves the experience of a self-capable of acting on the world. Since causes must precede effects, the perceived temporal order of our actions and subsequent events should be relevant to the sense of agency. The present study investigated whether the ability to predict the outcome of an action would impose the classical cause-precedes-outcome pattern on temporal order judgements. Participants indicated whether a visual stimulus (dots moving upward or downward) was presented either before or after voluntary actions of the left or right hand. Crucially, the dot motion could be either congruent or incongruent with an operant association between hand and motion direction learned in a previous learning phase. When the visual outcome of voluntary action was congruent with previous learning, the motion onset was more often perceived as occurring after the action, compared to when the outcome was incongruent. This suggests that the prediction of specific sensory outcomes restructures our perception of timing of action and sensory events, inducing the experience that congruent effects occur after participants' actions. Interestingly, this bias to perceive events according to the temporal order of cause and outcome disappeared when participants knew that motion directions were automatically generated by the computer. This suggests that the reorganisation of time perception imposed by associative learning depends on participants' causal beliefs
PyNAST: a flexible tool for aligning sequences to a template alignment
Motivation: The Nearest Alignment Space Termination (NAST) tool is commonly used in sequence-based microbial ecology community analysis, but due to the limited portability of the original implementation, it has not been as widely adopted as possible. Python Nearest Alignment Space Termination (PyNAST) is a complete reimplementation of NAST, which includes three convenient interfaces: a Mac OS X GUI, a command-line interface and a simple application programming interface (API)
Testicular activity and sperm glycoproteins in giant red shrimp Aristaeomorpha foliacea
The reproduction of male giani red shrimp Aristaeomorpha foliacea, collected from thè late
winterto thè summer in thè north-western lonian Sea (Mediterranean Sea), was investigated using
histological and histochemistry methods. Seasonal changes in thè spermiogenesis and thè glycoprotein
pattern were found and sperm glycoproteins matured as gametes moved from thè testis to
thè terminal ampliila. In serial sections stained with hematoxylin and eosin thè testicular activity
appeared to be discontinuous. In late winter thè testes had no meiotic activity and thè seminiferous
epithelium consisted of interkinetic spermatogonia and spermatozoa. In spring, spermiogenetic
activity was high and thè seminiferous epithelium mainly consisted of spermatocytes and spermatozoa
while in summer, thè testes were again inactive since both spermatocytes and spermatozoa
were lacking. The use of twelve different lectins indicated that thè intratesticular spermatozoa
from late winter to summer contain surface binding sites for SNA, MAA, Con A and KOH-sialidase
(si)-WGA. In March and July they also exhibited nuclear and cytoplasmic reactivity for SNA and
Con A. In thè hemispermatophore thè spermatozoa displayed a more complex lectin-binding pattern
because they also reacted with PNA, DBA, HPA, OSA II. The staining with DBA, KOH-si-
DBA, and OSA II showed differences between thè spermatozoa from late winter-spring
hemispermatophores and summer hemispermatophores: thè former showed a nuclear affinity
whereas thè latter displayed surface and/or cytoplasm staining. No reaction was observed with
SBA, GSAI-B4, UEA I, and LTA
Further observations on the sensitive innervation of some bird’s proctodeum
The AA. studied the autonomic and sensitive somatic innervation of some female bird's proctodeum, through the properly modified Ruffini's gold chloride method. The vegetative component was constituted by ganglion cells of different size, isolated or grouped to form ganglia, found along the course of nerve trunks or in the concurrent point of different nerve bundles. The sensitive somatic innervation was represented by free and encapsulated endings differently distributed in the thickness of the wall. The former were composed of thin networks, while the latter, located more frequently in the muscular tunica and in the subadventitial connective, were composed of encapsulated receptors classified as Pacini, Pacini-like and Herbst corpuscles. The morphology of these receptors was described and hypotheses were brought up about their probable functional role. The AA. also found, even if very rarely, helicoidal collagen fibres around nerve fascicles
Histochemical analysis of glycoconjugates in the domestic cat testis
The localization and characterization of
oligosaccharide sequences in the cat testis was
investigated using 12 lectins in combination with the ßelimination
reaction, N-Glycosidase F and sialidase
digestion. Leydig cells expressed O-linked glycans with
terminal aGalNAc (HPA reactivity) and N-glycans with
terminal/internal aMan (Con A affinity). The basement
membrane showed terminal Neu5Aca2,6Gal/GalNAc,
Galß1,3GalNAc, a/ßGalNAc, and GlcNAc (SNA, PNA,
HPA, SBA, GSA II reactivity) in O-linked oligosaccharides,
terminal Galß1,4GlcNAc (RCA120 staining)
and aMan in N-linked oligosaccharides; in addition,
terminal Neu5Aca2,3Galß1,4GlcNac, Forssman
pentasaccharide, aGal, aL-Fuc and internal GlcNAc
(MAL II, DBA, GSA I-B4, UEA I, KOH-sialidase-WGA
affinity) formed both O- and N-linked oligosaccharides.
The Sertoli cells cytoplasm contained terminal Neu5Ac-
Galß1,4GlcNAc, Neu5Ac-ßGalNAc as well as internal
GlcNAc in O-linked glycans, aMan in N-linked
glycoproteins and terminal Neu5Aca2,6Gal/
GalNAc in both O- and N-linked oligosaccharides.
Spermatogonia exhibited cytoplasmic N-linked
glycoproteins with aMan residues. The spermatocytes
cytoplasm expressed terminal Neu5Aca2,3Galß1,4
GlcNAc and Galß1,3GalNAc in O-linked oligosaccharides,
terminal Galß1,4GlcNAc and a/ßGalNAc
in N-linked glycoconjugates. The Golgi region showed
terminal Neu5aca2,3Galß1,4GlcNac, Galß1,4GlcNAc,
Forssman pentasaccharide, and aGalNAc in O-linked
oligosaccharides, aMan and terminal ßGal in N-linked
oligosaccharides. The acrosomes of Golgi-phase
spermatids expressed terminal Galß1,3GalNAc,
Galß1,4GlcNAc, Forssmann pentasaccharide,
a/ßGalNAc, aGal and internal GlcNAc in O-linked
oligosaccharides, terminal a/ßGalNAc, aGal and
terminal/internal aMan in N-linked glycoproteins. The
acrosomes of cap-phase spermatids lacked internal
Forssman pentasaccharide and aGal, while having
increased a/ßGalNAc. The acrosomes of elongated
spermatids did not show terminal Galß1,3GalNAc,
displayed terminal Galß1,4GlcNAc and a/ßGalNAc in
N-glycans and Neu5Ac-Galß1,3GalNAc in O-linked
oligosaccharides
Riflettanza di superfici vulcaniche:la campagna 2003 sul Monte Etna
The results obtained in Mt. Etna spectroradiometric field survey of June 2003 are presented and discussed. The goal of the survey was the analysis of the reflectance properties of the young pyroclastic deposits produced after the effusive activity of 2002-2003 and of the older lava flows. To achieve this goal, a template was created in order to organize the field data collected in a number of selected sites characterised by different surface materials. The results show that reflectance of pyroclastic flows is always very low and constant, besides grain size and composition of the flow. Pahoehoe units show higher reflectance values, even though the spectral characterisation of the older lava flows must take into account weathering
products and vegetation coverage
An Afferent Vagal Nerve Pathway Links Hepatic PPARα Activation to Glucocorticoid-Induced Insulin Resistance and Hypertension
SummaryGlucocorticoid excess causes insulin resistance and hypertension. Hepatic expression of PPARα (Ppara) is required for glucocorticoid-induced insulin resistance. Here we demonstrate that afferent fibers of the vagus nerve interface with hepatic Ppara expression to disrupt blood pressure and glucose homeostasis in response to glucocorticoids. Selective hepatic vagotomy decreased hyperglycemia, hyperinsulinemia, hepatic insulin resistance, Ppara expression, and phosphoenolpyruvate carboxykinase (PEPCK) enzyme activity in dexamethasone-treated Ppara+/+ mice. Selective vagotomy also decreased blood pressure, adrenergic tone, renin activity, and urinary sodium retention in these mice. Hepatic reconstitution of Ppara in nondiabetic, normotensive dexamethasone-treated PPARα null mice increased glucose, insulin, hepatic PEPCK enzyme activity, blood pressure, and renin activity in sham-operated animals but not hepatic-vagotomized animals. Disruption of vagal afferent fibers by chemical or surgical means prevented glucocorticoid-induced metabolic derangements. We conclude that a dynamic interaction between hepatic Ppara expression and a vagal afferent pathway is essential for glucocorticoid induction of diabetes and hypertension
NRAGE associates with the anti-apoptotic factor Che-1 and regulates its degradation to induce cell death
Neurotrophin receptor-interacting MAGE homolog (NRAGE) has been recently identified as a cell-death inducer, involved in molecular events driving cells through apoptotic networks during neuronal development. Recently, we have focused on the functional role of Che-1, also known as apoptosis-antagonizing transcription factor (AATF), a protein involved in cell cycle control and gene transcription. Increasing evidence suggests that Che-1 is involved in apoptotic signalling in neural tissues. In cortical neurons Che-1 exhibits an anti-apoptotic activity, protecting cells from neuronal damage induced by amyloid β-peptide. Here, we report that Che-1 interacts with NRAGE and that an EGFP-NRAGE fusion protein inhibits nuclear localization of Che-1, by sequestering it within the cytoplasmic compartment. Furthermore, NRAGE overexpression downregulates endogenous Che-1 by targeting it for proteasome-dependent degradation. Finally, we propose that Che-1 is a functional antagonist of NRAGE, because its overexpression completely reverts NRAGE-induced cell-death
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