383 research outputs found
Yes, they can! Three-banded armadillos Tolypeutes sp. (Cingulata: Dasypodidae) dig their own burrows.
It is believed that the two species of Tolypeutes Illiger, 1811are the only armadillos that do not dig their own burrows, and that these species simply re-use burrows dug by other species. Here, we show that Tolypeutes matacus (Desmarest, 1804) and Tolypeutes tricinctus (Linnaeus, 1758) dig their own burrows. We describe the burrows and three other types of shelters used by them, and provide measurements and frequency of use of the different types of shelter. We have studied free-ranging individuals of T. matacus in two locations in Central Brazil and individuals of T. tricinctus in semi-captivity in the Northeast of Brazil. Individuals of T. matacus were found primarily in small burrows (76%), straw nests (13%), shallow depressions covered with leaf-litter (7%) or in straw nests made on shallow depressions (4%). Adult males and females of T. matacus did not differ in frequency of use of different types of shelter. Sub-adults T. matacus used shallow depressions and nests more often (40%) than adults (22%) and nurslings (10%). Nurslings of T. matacus reused the shelters more frequently (66%), than sub-adults (46%) and adults (35%). Adult females reused burrows and other types of shelter more frequently than adult males. Tolypeutes tricinctus rested mainly in burrows and under leaf-litter, but did not dig depressions or build nests. Tolypeutes tricinctus occasionally used burrows dug by Euphractus sexcinctus (Linnaeus, 1758), but T. matacus never used burrows dug by other species. Nursling T. matacus always shared shelter with an adult female therefore, both used shelters with similar frequency. Adult females and nurslings of T. matacus reused shelters in higher frequency. That can be explained by the fact that adult females with offspring tend to remain for consecutive nights in the same burrow when cubs are recently born. Due to their smaller body size, subadult T. matacus used shelter strategies that require less energetic effort more frequently than adults and nurslings. The habit of covering the burrow entrance with foliage and the burrow?s reduced depth, indicates that Tolypeutes use of burrows is more likely to be related to parental care behavior and thermoregulation strategies than to defense mechanisms. We are confident that the burrows used for resting were indeed dug by Tolypeutes because, besides the direct observation of armadillos digging burrows, the measures of the burrows are very distinctive from those presented as characteristic for the co-occurring burrowing species and are congruent with Tolypeutes size and carapace shape. The newly acquired knowledge that species of Tolypeutes dig burrows can be used to increase the well-being of individuals kept in captivity by adapting enclosures to enable their digging behavior. In addition, this information contributes not only to the study of the ecology and natural history of the species, but can shed new light on the study of the anatomy of specialized diggers. Tolypeutes spp. can comprise the least fossorial of all living armadillo species, but they can no longer be classified as non-diggers
The Choice of Treatment in Ischemic Mitral Regurgitation With Reduced Left Ventricular Function
âI think I'm more free with them'âConflict, Negotiation and Change in Intergenerational Relations in African Families Living in Britain
While the family is increasingly being recognised as pivotal to migration, there remain too few studies examining how migration impacts on intergenerational relationships. Although traditional intergenerational gaps are intensified by migration, arguably there has been an over-emphasis on the divisions between âtraditionalâ parents and âmodernâ children at the expense of examining the ways in which both generations adapt. As Foner and Dreby [2011. âRelations Between the Generations in Immigrant Families.â Annual Review of Sociology 37: 545â564] stress, the reality of post-migration intergenerational relations is inevitably more complex, requiring the examination of both conflict and cooperation. This article contributes to this growing literature by discussing British data from comparative projects on intergenerational relations in African families (in Britain, France and South Africa). It argues that particular understandings can be gained from examining the adaptation of parents and parenting strategies post-migration and how the reconfiguration of family relations can contribute to settlement. By focusing on how both parent and child generations engage in conflict and negotiation to redefine their relationships and expectations, it offers insight into how families navigate and integrate the values of two cultures. In doing so, it argues that the reconfiguration of gender roles as a result of migration offers families the space to renegotiate their relationships and make choices about what they transmit to the next generation
Comparing Welfare Regime Changes: Living Standards and the Unequal Life Chances of Different Birth Cohorts
The cohort sustainability of welfare regimes is of central importance to most long-term analyses of welfare state reforms (see for example: Esping-Andersen et al., 2002). A complement to these analyses shows that changes in intra versus inter cohort inequalities are major outcomes or consequences of the trajectories of the different welfare regimes. Previous comparative research papers show the difference between France and the United-States, since the American intra-cohort inequalities have increased strongly for the last three decades, when the French case show less intra-cohort inequalities and more inter-cohort imbalances at the expense of younger generations of adults (Chauvel 2006). Here, we propose a comparison between the US, Danish, French, and Italian dynamics of distribution of after tax and transfers equivalised income by age, period and cohort, to assess how different welfare regimes gave different trade-offs between intra and inter cohort inequality. The Luxembourg Income Study (LIS) data are used to analyze the transformations of the intra cohort inequalities (based on interdecile ratios) and the changes in the cohort life chances. The main result is that the conservative and the familialistic welfare regimes are marked by more inter-cohort inequalities to the expense of young social generations, who are relatively impoverished, when the social-democrat and the liberal ones show less inter-cohort redistribution of resources, but increasing intra-cohort inequality, particularly in the case of the US. In terms of cohort sustainability of welfare regimes, the French and Italian dynamics seem to be unsustainable since the contemporary well-off seniors are flowed by impoverished mid-aged groups who will be poor seniors of the 2020s
Complex sequencing rules of birdsong can be explained by simple hidden Markov processes
Complex sequencing rules observed in birdsongs provide an opportunity to
investigate the neural mechanism for generating complex sequential behaviors.
To relate the findings from studying birdsongs to other sequential behaviors,
it is crucial to characterize the statistical properties of the sequencing
rules in birdsongs. However, the properties of the sequencing rules in
birdsongs have not yet been fully addressed. In this study, we investigate the
statistical propertiesof the complex birdsong of the Bengalese finch (Lonchura
striata var. domestica). Based on manual-annotated syllable sequences, we first
show that there are significant higher-order context dependencies in Bengalese
finch songs, that is, which syllable appears next depends on more than one
previous syllable. This property is shared with other complex sequential
behaviors. We then analyze acoustic features of the song and show that
higher-order context dependencies can be explained using first-order hidden
state transition dynamics with redundant hidden states. This model corresponds
to hidden Markov models (HMMs), well known statistical models with a large
range of application for time series modeling. The song annotation with these
models with first-order hidden state dynamics agreed well with manual
annotation, the score was comparable to that of a second-order HMM, and
surpassed the zeroth-order model (the Gaussian mixture model (GMM)), which does
not use context information. Our results imply that the hierarchical
representation with hidden state dynamics may underlie the neural
implementation for generating complex sequences with higher-order dependencies
Mammals, Serra da ConcĂłrdia, state of Rio de Janeiro, Brazil.
The Atlantic Forest in the state of Rio de Janeiro is extremely fragmented and reduced in its originalextension. Although there are a great number of studies related to the biome, few lists are available for this region. Thepresent study seeks to get information on the mammals of a remnant forest in Serra da ConcĂłrdia, an area from whichno information is currently available. The rapid mammal's survey was accomplished by use of pitfalls, live traps,transects, mist nets, and camera traps. We recorded 37 terrestrial species that represent 22.3 % of Rio de Janeiro statemammal species. Among the recorded species, six are endemic of the Atlantic Forest, one is endemic of the state, andeight are in the state list of threatened or presumably threatened species. The area presents great mammal richness andan increasing effort will probably reveal the presence of additional species
Self-consistent quantal treatment of decay rates within the perturbed static path approximation
The framework of the Perturbed Static Path Approximation (PSPA) is used to
calculate the partition function of a finite Fermi system from a Hamiltonian
with a separable two body interaction. Therein, the collective degree of
freedom is introduced in self-consistent fashion through a Hubbard-Stratonovich
transformation. In this way all transport coefficients which dominate the decay
of a meta-stable system are defined and calculated microscopically. Otherwise
the same formalism is applied as in the Caldeira-Leggett model to deduce the
decay rate from the free energy above the so called crossover temperature
.Comment: 17 pages, LaTex, no figures; final version, accepted for publication
in PRE; e-mail: [email protected]
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Whole-exome sequencing identifies an α-globin cluster triplication resulting in increased clinical severity of ÎČ-thalassemia
Whole-exome sequencing (WES) has been increasingly useful for the diagnosis of patients with rare causes of anemia, particularly when there is an atypical clinical presentation or targeted genotyping approaches are inconclusive. Here, we describe a 20-yr-old man with a lifelong moderate-to-severe anemia with accompanying splenomegaly who lacked a definitive diagnosis. After a thorough clinical workup and targeted genetic sequencing, we identified a paternally inherited ÎČ-globin mutation (HBB:c.93-21G>A, IVS-I-110:G>A), a known cause of ÎČ-thalassemia minor. As this mutation alone was inconsistent with the severity of the anemia, we performed WES. Although we could not identify any relevant pathogenic single-nucleotide variants (SNVs) or small indels, copy-number variant (CNV) analyses revealed a likely triplication of the entire α-globin cluster, which was subsequently confirmed by multiplex ligation-dependent probe amplification. Treatment and follow-up was redefined according to the diagnosis of ÎČ-thalassemia intermedia resulting from a single ÎČ-thalassemia mutation in combination with an α-globin cluster triplication. Thus, we describe a case where the typical WES-based analysis of SNVs and small indels was unrevealing, but WES-based CNV analysis resulted in a definitive diagnosis that informed clinical decision-making. More generally, this case illustrates the value of performing CNV analysis when WES is otherwise unable to elucidate a clear genetic diagnosis
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