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Background The aims of this study were: to investigate the capacity of the rare disease healthcare network in Campania to diagnose patients with rare diseases during the outbreak of Covid-19; and to shed light on problematic diagnoses during this period. Methods To describe the impact of the Covid-19 pandemic on the diagnosis of patients with rare diseases, a retrospective analysis of the Campania Region Rare Disease Registry was performed. A tailored questionnaire was sent to rare disease experts to investigate major issues during the emergency period. Results Prevalence of new diagnoses of rare disease in March and April 2020 was significantly lower than in 2019 (117 versus 317, P Conclusions This study describes the effects of the Covid-19 outbreak on the diagnosis of rare disease in a single Italian region and investigates potential issues of diagnosis and management during this period.

In volleyball games, we define a rally as the succession of events observed since the ball is served until one of the two teams on the court scores the point. In this process, athletes evolve in response to physical and information constraints, spanning several spatiotemporal scales and interplaying co-adaptively with the environment. Aiming to study the emergence of complexity in this system, we carried out a study focused on three steps: data collection, data analysis, and modeling. First, we collected data from 20 high-level professional volleyball games. Then we conducted a data-driven analysis from where we identified fundamental insights that we used to define a parsimonious stochastic model for the dynamics of the game. On these bases, we show that it is possible to give a closed-form expression for the probability that the players perform n hits in a rally using only two stochastic variables. Our results fully agree with the empirical observations and represent a new advance in the comprehension of team-sports competition complexity and dynamics.

Using the Cap Analysis of Gene Expression (CAGE) technology, the FANTOM5 consortium provided one of the most comprehensive maps of transcription start sites (TSSs) in several species. Strikingly, ~72% of them could not be assigned to a specific gene and initiate at unconventional regions, outside promoters or enhancers. Here, we probe these unassigned TSSs and show that, in all species studied, a significant fraction of CAGE peaks initiate at microsatellites, also called short tandem repeats (STRs). To confirm this transcription, we develop Cap Trap RNA-seq, a technology which combines cap trapping and long read MinION sequencing. We train sequence-based deep learning models able to predict CAGE signal at STRs with high accuracy. These models unveil the importance of STR surrounding sequences not only to distinguish STR classes, but also to predict the level of transcription initiation. Importantly, genetic variants linked to human diseases are preferentially found at STRs with high transcription initiation level, supporting the biological and clinical relevance of transcription initiation at STRs. Together, our results extend the repertoire of non-coding transcription associated with DNA tandem repeats and complexify STR polymorphism., Nature Communications, 12 (1), ISSN:2041-1723

O objetivo do presente trabalho foi sintetizar, caracterizar e avaliar a atividade antioxidante in vitro de fitocomplexos produzidos pela mistura das fracoes em hexano, diclorometano, acetato de etila e butanol de Bryophyllum pinnatum (Lam.) Oken com beta-ciclodextrina (βCD). Apos a producao, os fitocomplexos foram caracterizados em solucao e no estado solido por espectroscopia na regiao do UV-vis e analise termogravimetrica, sendo possivel demonstrar a preferencia da βCD pelas fracoes ricas em flavonoides (acetato de etila e butanol). Quanto a avaliacao da atividade antioxidante, ambas as metodologias utilizadas no estudo, DPPH e FRAP, mostraram que a fracao em acetato de etila foi a que apresentou melhoria da atividade antioxidante na presenca de βCD, como resultado das interacoes dos flavonoides com a ciclodextrina.

In this paper, we study collective interaction dynamics emerging in the game of football (soccer). To do so, we surveyed a database containing body-sensor traces measured during three professional football matches, where we observed statistical patterns that we used to propose a stochastic model for the players' motion in the field. The model, which is based on linear interactions, captures to a good approximation the spatiotemporal dynamics of a football team. Our theoretical framework, therefore, can be an effective analytical tool to uncover the underlying cooperative mechanisms behind the complexity of football plays. Moreover, we showed that it can provide handy theoretical support for coaches to evaluate teams' and players' performances in both training sessions and competitive scenarios.

In this paper, we study the magnetic properties of orthorhombic (Pbnm) perovskites $\mathrm{Lu}{\mathrm{Fe}}_{1\ensuremath{-}x}{\mathrm{Cr}}_{x}{\mathrm{O}}_{3}$ with $x=0.25$, 0.45, 0.55, and 0.75 by magnetization vs temperature and neutron powder diffraction measurements at room temperature. The magnetic moments are oriented along the $x$ direction with a G-type antiferromagnetic (AFM) arrangement that corresponds to irreducible representation ${\mathrm{\ensuremath{\Gamma}}}_{4}$ (${G}_{x}{A}_{y}{F}_{z}$). Magnetization reversal (MR) is observed for $0.45\ensuremath{\le}x\ensuremath{\le}0.75$. The MR phenomenon was modeled using Monte Carlo simulations, modeling both homogeneous and inhomogeneous cation distributions. For $\mathrm{Lu}{\mathrm{Fe}}_{0.25}{\mathrm{Cr}}_{0.75}{\mathrm{O}}_{3}$, the presence of MR could only be explained using an inhomogeneous distribution with well-defined magnetic clusters. Looking at the staggered magnetization of each cluster, we propose a superparamagnetic regime of ${\mathrm{Fe}}^{3+}$ clusters in a ${\mathrm{Cr}}^{3+}$-rich matrix for $\mathrm{Lu}{\mathrm{Fe}}_{0.25}{\mathrm{Cr}}_{0.75}{\mathrm{O}}_{3}$. By calculating the specific heat, we found that, in $\mathrm{Lu}{\mathrm{Fe}}_{0.45}{\mathrm{Cr}}_{0.55}{\mathrm{O}}_{3}$ and $\mathrm{Lu}{\mathrm{Fe}}_{0.25}{\mathrm{Cr}}_{0.75}{\mathrm{O}}_{3}$ the clusters order at nearly the same temperature ${T}_{N}^{\mathrm{Clus}}\ensuremath{\sim}535$ and 520 K, respectively, while the matrix orders at ${T}_{N}^{\mathrm{Mat}}\ensuremath{\sim}115\phantom{\rule{0.16em}{0ex}}\mathrm{K}$. There is considerable reduction in the cluster ordering temperature as compared with the bulk, as ${T}_{N}\ensuremath{\sim}628\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ for $\mathrm{LuFe}{\mathrm{O}}_{3}$, while the matrix orders at the expected temperature as ${T}_{N}\ensuremath{\sim}115\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ for $\mathrm{LuCr}{\mathrm{O}}_{3}$.

In the present paper, we study the robustness of two-dimensional random lattices (Delaunay triangulations) under attacks based on betweenness centrality. Together with the standard definition of this centrality measure, we employ a range-limited approximation known as $\ell$-betweenness, where paths having more than $\ell$ steps are ignored. For finite $\ell$, the attacks produce continuous percolation transitions that belong to the universality class of random percolation. On the other hand, the attack under the full range betweenness induces a discontinuous transition that, in the thermodynamic limit, occurs after removing a sub-extensive amount of nodes. This behavior is recovered for $\ell$-betweenness if the cutoff is allowed to scale with the linear length of the network faster than $\ell\sim L^{0.91}$. Our results suggest that betweenness centrality encodes information on network robustness at all scales, and thus cannot be approximated using finite-ranged calculations without losing attack efficiency., Comment: 11 pages, 6 figures, supplementary material

In this paper, we study interaction dynamics in the game of football-soccer in the context of ball possession intervals. To do so, we analyze a database comprising one season of the five major football leagues of Europe. Using this input, we developed a stochastic model based on three agents: two teammates and one defender. Despite its simplicity, the model is able to capture, in good approximation, the statistical behavior of possession times, pass lengths, and number of passes performed. In the last section, we show that the model's dynamics can be mapped into a Wiener process with drift and an absorbing barrier. Fil: Chacoma, Andrés Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina Fil: Almeira, Nahuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina Fil: Perotti, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina Fil: Billoni, Orlando Vito. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina

Aquatic invertebrates use antioxidant systems to endure intertidal environments, where temperature, oxygen availability and radiation incidence vary greatly. The upregulation of antioxidants during oxygen-limiting conditions, such as intertidal aerial exposure (AE), is known as preparation for oxidative stress (POS). Preparation for oxidative stress has been commonly reported for animals exposed to hypoxia in the lab, but few studies have investigated it under ecologically relevant natural settings. Here, we studied metabolic enzymes, antioxidants, and oxidative stress markers in Brachidontes solisianus mussels exposed to a natural tidal cycle in a rocky beach in Southern Brazil. Animals were collected at 6 time-points throughout the tidal cycle: after 2 h of AE; then after 1 h, 3 h, and 7 h of immersion; followed by 0.5 h and 4 h of AE. The activities of malate dehydrogenase, isocitrate dehydrogenase, and pyruvate kinase were unaffected by aerial exposure. Similarly, the acitivities of enzymes of the antioxidant system, catalase, glutathione transferase, glutathione reductase, and glucose 6-phosphate dehydrogenase did not change significantly throughout the tidal cycle. In contrast, total and reduced glutathione levels significantly increased at 4 h AE by 47% and 64%, respectively, compared with those in submerged mussels (1 h, 3 h, and 7 h immersion groups combined). Lipid peroxidation and carbonyl protein levels significantly increased after 4 h of AE compared with those in mussels underwater for 7 h. Our results indicate the occurrence of POS in B. solisianus mussels exposed to air under natural conditions during tidal cycles.

We propose a stochastic model to study phonetic changes as an evolutionary process driven by social interactions between two groups of individuals with different phonological systems. Particularly, we focus on the changes in the place of articulation, inspired by the drift/φ/→/h/observed in some words of Latin root in the Castilian language. In the model, each agent is characterized by a variable of three states, representing the place of articulation used during speech production. In this frame, we propose stochastic rules of interactions among agents which lead to phonetic imitation and consequently to changes in the articulation place. Based on this, we mathematically formalize the model as a problem of population dynamics, derive the equations of evolution in the mean-field approximation, and study the emergence of three nontrivial global states, which can be linked to the pattern of phonetic changes observed in the language of Castile and in other Romance languages. Fil: Chacoma, Andrés Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina Fil: Almeira, Nahuel. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina Fil: Perotti, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina Fil: Billoni, Orlando Vito. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina

Evidence of critical dynamics has been recently found in both experiments and models of large scale brain dynamics. The understanding of the nature and features of such critical regime is hampered by the relatively small size of the available connectome, which prevent among other things to determine its associated universality class. To circumvent that, here we study a neural model defined on a class of small-world network that share some topological features with the human connectome. We found that varying the topological parameters can give rise to a scale-invariant behavior belonging either to mean field percolation universality class or having non universal critical exponents. In addition, we found certain regions of the topological parameters space where the system presents a discontinuous (i.e., non critical) dynamical phase transition into a percolated state. Overall these results shed light on the interplay of dynamical and topological roots of the complex brain dynamics., Comment: 6 pages, 6 figures

Zipf's law is found when the vocabulary of long written texts is ranked according to the frequency of word occurrences, establishing a power-law decay for the frequency vs rank relation. This law is a robust statistical property observed even in ancient untranslated languages. Interestingly, this law seems to be also manifested in music records when several metrics---functioning as words in written texts---are used. Even though music can be regarded as a language, finding an accurate equivalent of the concept of words in music is difficult because it lacks a functional semantic. This raises the question of which is the appropriate choice of Zipfian units in music, which is extensive to other contexts where this law can emerge. In particular, this is still an open question in written texts, where several alternatives have been proposed as Zipfian units besides the canonical use of words. Seeking to validate a natural election of Zipfian units in music, in this work we find that Zipf's law emerges when a combination of chords and notes are chosen as Zipfian units. Our results are grounded on a consistent analysis of the statistical properties of music and texts, complemented with theoretical considerations that combine different reference models, including a simple model inspired in the Lempel-Ziv compression algorithm that we have devised to explain the emergence of Zipf's law as the consequence of languages evolving into more efficient forms of communication., Published in Physica A: Statistical Mechanics and its Applications

In this work we introduce a variant of the Yule-Simon model for preferential growth by incorporating a finite kernel to model the effects of bounded memory. We characterize the properties of the model combining analytical arguments with extensive numerical simulations. In particular, we analyze the lifetime and popularity distributions by mapping the model dynamics to corresponding Markov chains and branching processes, respectively. These distributions follow power-laws with well defined exponents that are within the range of the empirical data reported in ecologies. Interestingly, by varying the innovation rate, this simple out-of-equilibrium model exhibits many of the characteristics of a continuous phase transition and, around the critical point, it generates time series with power-law popularity, lifetime and inter-event time distributions, and non-trivial temporal correlations, such as a bursty dynamics in analogy with the activity of solar flares. Our results suggest that an appropriate balance between innovation and oblivion rates could provide an explanatory framework for many of the properties commonly observed in many complex systems., 10 pages, 8 figures

The increasing emission of electromagnetic waves by various devices has increased concerns of possible health effects. Exposure to ultra-high-frequency (UHF) radiation is increasing due to the development of wireless communication technologies. This type of radiation has been linked to changes in organisms through the generation of RS (Oxygen and Nitrogen). The aim of this review was to discuss the effects of ultra-high-frequency electromagnetic radiation (UHF-EMR) on the metabolism of RS and its consequences for mammals. It was discussed the relationship of UHF electromagnetic waves with oxidants and antioxidants in mammals. After reviewing several studies, it is concluded that UHF-EMR can cause changes in biomarkers of oxidative/nitrosative damage and can cause decreases in antioxidant defenses, which may result from these biomarkers’ fight against the oxidative damage to macromolecules induced by ROS/RNS.

We introduce a coarse-grained model capable of describing the phase behavior of two-dimensional ferromagnetic systems with competing exchange and dipolar interactions, as well as an external magnetic field. An improved expression for the mean-field entropic contribution allows us to compute the phase diagram in the whole temperature versus external field plane. We find that the topology of the phase diagram may be qualitatively different depending on the ratio between the strength of the competing interactions. In the regime relevant for ultrathin ferromagnetic films with perpendicular anisotropy we confirm the presence of inverse-symmetry breaking from a modulated phase to a homogeneous one as the temperature is lowered at constant magnetic field, as reported in experiments. For other values of the competing interactions we show that reentrance may be absent. Comparing thermodynamic quantities in both cases, as well as the evolution of magnetization profiles in the modulated phases, we conclude that the reentrant behavior is a consequence of the suppression of domain wall degrees of freedom at low temperatures at constant fields.

Using a time quantified Monte Carlo scheme we performed simulations of the switching time distribution of single mono-domain particles in the Stoner-Wohlfarth approximation. We considered uniaxial anisotropy and different conditions for the external applied field. The results obtained show the switching time distribution can be well described by two relaxation times, either when the applied field is parallel to the easy axis or for an oblique external field and a larger damping constant. We found that in the low barrier limit these relaxation times are in very good agreement with analytical results obtained from solutions of the Fokker-Planck equation related to this problem. When the damping is small and the applied field is oblique the shape of the distribution curves shows several peaks and resonance effects., Comment: 12 pages, 5 figures. New references, changes in the title and minor corrections

Crocodilians and other diving vertebrates experience hypoperfusion and hypoxia of several internal organs during long dives. At the end of a dive, reperfusion of aerated blood may cause a physiologically relevant oxidative stress. In this study, we analyzed selected markers of oxidative stress in eight organs of normoxic Paraguayan caiman (Caiman yacare) captured in the Brazilian Pantanal wetlands during the winter of 2001 (six mature-adult males and eight young-adult males; AD-1 and YA-1 groups, respectively), and during the summer of 2002 (six young-adult males (YA-2 group), ten hatchlings and five embryos). Lipid peroxidation products determined by three different assays were generally highest in brain, liver and kidney (in comparison with all other organs), and lowest in white muscles from the tail and hind legs. Liver and kidney showed the highest levels of carbonyl protein, while brain showed low levels. Intermediate levels of oxidative stress markers were mostly found in the heart ventricles and lung. Differences in oxidative stress markers between AD-1 and YA-1 were organ-specific, showing no age-related correlation. However, most oxidative stress markers in YA-2 organs were either higher than (by 1.4- to 3.7-fold) or not significantly different from respective values in hatchlings organs. This pattern (hatchlings versus young-adults) was confirmed using correlation analysis of individual caiman size versus levels of oxidative damage markers in four organs. The higher level of oxidative stress markers in young-adults possibly relates to the fast growth rate (and thus, increased oxidative metabolic rate) of C. yacare in the first years of life. Differences in oxidative stress markers between YA-1 and YA-2 were also observed and were ascribed to seasonal changes in free radical metabolism. These results in normoxic C. yacare represent the first step towards understanding the age-related physiological oxidative stress of a diving reptile from a seasonally changing wetland environment.

In evolution, body plan complexity increases due to an increase in the number of individualized cell types. Yet, there is very little understanding of the mechanisms that produce this form of organismal complexity. One model for the origin of novel cell types is the sister cell-type model. According to this model, each cell type arises together with a sister cell type through specialization from an ancestral cell type. A key prediction of the sister cell-type model is that gene expression profiles of cell types exhibit tree structure. Here we present a statistical model for detecting tree structure in transcriptomic data and apply it to transcriptomes from ENCODE and FANTOM5. We show that transcriptomes of normal cells harbour substantial amounts of hierarchical structure. In contrast, cancer cell lines have less tree structure, suggesting that the emergence of cancer cells follows different principles from that of evolutionary cell-type origination.

The hard magnetic properties of melt spun Nd 60 Fe 30 Al 10 alloys are attributed to a major matrix nominally amorphous for X-ray diffraction, composed by two metastable nanosized (∼5 nm) phases with different intrinsic magnetic properties. This composite system is investigated for the first time by mechanical spectroscopy techniques in the temperature range between 50 K and 450 K (1 kHz) where large annealing effects and two damping phenomena are detected. The as-cast microstructure irreversibly changes during annealing above 330 K, leading to a large modulus recovery accompanied by a reduction in the internal friction level. A relatively large relaxation effect is observed about 290 K, evidenced by a narrow internal friction peak with the corresponding step in the elastic modulus; this peak remains stable under thermal cycling between 200 K and 300 K but is affected by aging at 330 K and practically vanishes after heating to 450 K. Another internal friction peak is observed at about 250 K which has associated an anomalous modulus effect; in this temperature range, the internal friction and the elastic modulus exhibit heating/cooling hysteresis, which strongly depends on the extreme temperatures of the thermal cycle, a behavior frequently associated to first-order phase transformations.

Alloys with compositions Nd60−xCxFe30Al10 (x=0, 1, 5 and 10) were processed by melt spinning at a tangential speed of 5 m/s. The as-cast ribbons were characterized by X-ray diffraction, Mossbauer Effect spectroscopy and their room temperature hysteresis loops. The substitution of Nd by C is found to affect the phase selection, from mainly DHCP-Nd for x=0 to DHCP-Nd /FCC-Nd for the other ones. Mossbauer spectra of all the as-cast samples indicate that Fe is present in crystalline magnetic phases as well as in a paramagnetic one. The major crystalline phase was identified as a μ-type (or A1) metastable phase, which is reported to have a large anisotropy field and a relatively high saturation polarization. Interstitial C stabilizes the μ-type phase and improves its average hyperfine field. The magnetic measurements display an increase of coercivity and remanence with the C concentration.

The effects of the cooling rate on the microstructure and magnetic properties of the melt-spun Nd60Fe30Al10 alloys are investigated by Mossbauer Effect (ME) spectroscopy and magnetic hysteresis loops measurements at different temperatures. It is found that the hard magnetic properties of these alloys are likely to be related to the presence of clusters of a metastable crystalline μ-type phase. It is observed that as the cooling rate increases, the amount of this magnetic μ-like phase component decreases in the benefit of an amorphous Nd-rich phase. This phase has an iron concentration, which increases with increasing the wheel speed, is paramagnetic at room temperature and becomes superparamagnetic below approximately 50 K and 100 K for slow and high cooling rates, respectively.

Hysteresis and relaxation properties of Nd 60 Fe 30 Al 10 partially amorphous alloys, processed by melt spinning at 5 m/s (V5), 10 m/s (V10) and 20 m/s (V20), are investigated. Specimens V20 show two-step hysteresis loops while relatively square loops, exhibiting magnespring effects, are found in samples V5. In these latter microstructures, the demagnetization process has associated a nearly constant fluctuations field of μ 0 H f =14.5 mT , and a characteristic activation length l ac =7 nm . These values are similar to those obtained for V10 and V20 at the hard irreversible susceptibility peak: 13.1 mT, 7.3 nm (V10) and 13.5 mT, 7.1 nm (V20), respectively. In specimens V5, hysteresis and thermal relaxation are controlled by the same distribution of energy barriers and the results obtained are consistent with a reversion process involving a nucleation mechanism in a magnetic grain of size l mg ∼ l ac , with l mg the exchange length in the amorphous phase. This characteristic length is estimated by considering the amorphous phase as a two-phase magnetic composite in which the hard Fe-rich clusters are coupled by exchange interactions, mediated by a surrounding Nd-rich phase.

The demagnetization processes in Nd 2 F 14 B+αFe nanocrystalline composites exhibiting square and two-step hysteresis loops are investigated. In all these microstructures, an expanding nucleus model (Global Model) reasonably describes the experimental results in the entire range of the demagnetization loop, provided different sites acting as inverse nucleus are considered. Nucleation is found to take place in both phases and under different coupling conditions exhibiting, in each case, a different reversion regime. Each regime has associated definite values of specific nucleus surface energy and effective local demagnetizing factor, which are similar in all the specimens, in spite of their different microstructures and compositions. These specific surface energy values are close to those expected for domain wall-like configurations resulting from competing interactions in the particular nucleation site, not always related to the intrinsic properties of the phase itself but largely determined by inter-grain interactions.

Results support the hypothesis that individuals transfer their training to the job when their ‘real’ environment matches or fits the preferred ‘ideal’ environment. Five aspects of environment were assessed: supervisory encouragement, sufficient resources, worker’s perceived freedom, workload pressures, and perceived worker creativity. In addition to the traditional criteria of hiring people whose skills match the job, organizations might consider creating environments to match employees’ needs.

The province of Benguet, situated in North Luzon, the Philippines, holds a large number of ancient mummified remains, mostly located within the municipality of Kabayan. Such bodies are mainly associated to the Ibaloy – one of the indigenous groups collectively known as Igorot – and are stored in natural rockshelters or caves carved into the stone, inside wooden coffins often obtained from hollowed pine tree segments. Recent inspections of some of these corpses, carried out in 2002 and 2012, indicated the nature of their mummification process as well as some details regarding their bioanthropological features. Although very little information was initially available on these bodies, the authors have gathered significant oral information on funerary rituals and attitudes towards the ancestors via interviews with the local elders, as well as data on the vegetal materials employed and the practice of tattooing. This paper is the first critical evaluation of these mummies and demonstrates the uniqueness and preciousness of this biocultural heritage now in danger.

Seeks to find predictors of learning organizations as determined by Marquardt’s Learning Organization Profile (1996). For this study, male and female professionals were asked to rate their perceptions about their organizations. They were asked to rate their organizational perceptions on rewards and recognition, training and education, information flow, vision and strategy, and individual team development. Finds that appropriate rewards and recognition are an undergirding structure to the learning organization and that an environment of knowledge sharing and learning systems is an indication of a learning organization. Results support the notion that interventions intended to aid in the metamorphose from a current organization state to that of a learning organization may wish to focus initially on these aspects.

The intrinsic values of the magnetic viscosity and the fluctuation field in a two phase composite Nd 2 Fe 14 B+0.18 vol. αFe were investigated. The composite studied, with equiaxed and isotropically oriented grains had mean grain sizes favoring a strong exchange coupling between the phases. The relations between the intrinsic and the experimentally measured magnitudes are reviewed and the approximations discussed. For applied fields close to the coercivity, the time dependence of the magnetization is not well described by a simple logarithmic law. The intrinsic fluctuation field is found to increase when the reverse internal field increases in all the ranges investigated and two different regimes are identified. These different regimes are discussed considering the distributions of critical fields for nucleation of inverse domains in the hard phase, at hard–soft and hard–hard grain boundaries, respectively.

Problem statement: The purpose of this study was to determine undergra duate student perceptions in the areas of group experience within the context of an undergraduate organizational behavior business class community service assignment. College students, as part of an in-class service - learning project, were assigned to teach business r elated curriculum to at-risk high school students. Approach: Students, enrolled in the required senior level bu siness course, were then assessed in the following areas: service learning experience and gr oup experience. A multiple-choice questionnaire was administered to undergraduate students in an or ganizational and administrative behavior class and analyzed for correlations and relationships. The su rvey was administered in week eleven of a traditional semester and in the last week of the co mmunity service project. The survey was comprised of seven questions relating to group experience and one based on the impact of the community service project itself. Results: Significant findings revealed a positive correlati on between the group experience and the feelings toward the project. In addition, multiple linear regressions suggested a positive an d significant prediction. Conclusion: From the findings, implications for the developmen t of experiential learning projects for use in the college classroom will be discussed. When paired with the results of previous research, the findings of this research ca n be very useful in developing group based service learning projects at the undergraduate level. Based upon the importance of service learning as an experiential teaching style, it is critical to unde rstand how to better use this vehicle for discovery .

The magnetomechanical coupling in a nanocrystalline ${\mathrm{Nd}}_{2}{\mathrm{Fe}}_{14}\mathrm{B}+0.18 \mathrm{vol} \ensuremath{\alpha} \mathrm{Fe}$ composite is investigated using mechanical spectroscopy technics. The internal friction and the elastic modulus are simultaneously measured between 4 and 300 K (800 Hz, $\ensuremath{\epsilon}l~{10}^{\ensuremath{-}4}).$ The composite magnetization is also measured as a function of temperature in the same range. The experiments are performed in the same sample exhibiting two different magnetic states. The state I is thermally demagnetized and domain walls are found in both phases. The state II, in which $\ensuremath{\alpha}$ Fe is saturated and the ${\mathrm{Nd}}_{2}{\mathrm{Fe}}_{14}\mathrm{B}$ grains are single domains, is attained by applying a dc magnetic field of 4.5 kOe during measurements. The elastic modulus increases during heating and in both states this recovering is correlated with the irreversible changes in the composite magnetization. The internal damping in the sample with a single domain configuration (state II) is higher than that found when both phases have multidomain grains (state I) in all the range investigated. Large contributions to the mechanical dissipation are related to irreversible changes in the magnetization by a nucleation mechanism in the ${\mathrm{Nd}}_{2}{\mathrm{Fe}}_{14}\mathrm{B}$ grains.

A mentoring relationship has the potential to be widely used throughout an individual’s lifespan. Including mentoring relationships into one’s life can assist with transition management in and out of various life scenarios. A mentoring model has been proposed that blends human development with the dimensions of mentoring. It is assumed that the dimensions of the model are continuous and multidimensional. We recognize three interactive dimensions that surround the mentoring interaction which shape the mentor and protégé relationship. These dimensions are defined as: socialization; task development; and lifespan development. The model can be utilized as a diagnostic tool or as a training model to promote mentoring relationships.

We have studied the angular dependence of the irreversible magnetization and its time relaxation in ${\mathrm{YBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{7}$ single crystals with one or two families of columnar defects inclined with respect to the c axis. At high magnetic fields, the magnetization shows the usual maximum centered at the mean tracks' orientation and an associated minimum in the normalized relaxation rate. In contrast, at low fields we observe an anomalous local minimum in the magnetization and a maximum in the relaxation rate. We present a model to explain this anomaly based on the slowing down of the creep processes arising from the increase of the vortex-vortex interactions as the applied field is tilted away from the mean tracks' direction.

The dependence on the mean grain size of the magnetic properties of isotropic nanocrystalline FeNdB+αFe composite magnets has been investigated. The grain size distribution was varied by changing the melt spinning conditions. It is found that both, the remanence and the coercivity increase as the mean grain size of the hard phase decreases from 80 to 25 nm, in good agreement with micromagnetic numerical calculations. The behavior of these properties is consistent with a process of exchange hardening of the soft phase as the grain size decreases. The effect of exchange coupling between different grains may be considered by introducing in the nucleation term of the modified Brown's equation a factor depending on the grain size distribution.

The study investigated the relationships of margin in life (MIL) and demographic variables to readiness for change. Results, based on 131 employees of a manufacturing company, showed that overall MIL and five work subscales had significant positive relationships with readiness for change. The demographic variables of department, position, and length of employment were also related to readiness for change but not to MIL. Three variables combined to predict readiness: employees who get more personal power than burden from their relations with managers, employees who themselves are in managerial positions, and employees who are relatively new to the company. Among the MIL subscales, all of the work aspects, except social relations in the workplace, had higher ratings on load than on power, whereas the reverse was true for the nonwork aspects of family, self, and health. The results suggest strategies to facilitate effective change interventions.

In this work, we perform Monte Carlo simulations to study the magnetization reversal mechanism in ferromagnetic thin films on FeF2. In particular, we emulate a bilayer AFM/FM structure, where the AFM interface corresponds to an uncompensated (1 0 0) plane. The magnetic moments are modeled by classical Heisenberg spin variables. Our analysis focus on the role of the exchange interaction J AF between the FM spins and the spins belonging to the AFM interface on the reversal mechanisms of the magnetization. By simulating hysteresis loops we study the effect of temperature on the bias field.

To assess the effect of 950 MHz ultra-high-frequency electromagnetic radiation (UHF EMR) on biomarkers of oxidative damage, as well as to verify the concentration of unsaturated fatty acids (UFA) and the expression of the catalase in the livers of rats of different ages.Twelve rats were equally divided into two groups as controls (CR) and exposed (ER), for each age (0, 6, 15 and 30 days). Radiation exposure lasted half an hour per day for up to 51 days (21 days of gestation and 6, 15 or 30 days of life outside the womb). The specific absorption rate (SAR) ranged from 1.3-1.0 W/kg. The damage to lipids, proteins and DNA was verified by thiobarbituric acid reactive substances (TBARS), protein carbonyls and comets, respectively. UFA were determined by gas chromatography with a flame ionization detector. The expression of catalase was by Western blotting.The neonates had low levels of TBARS and concentrations of UFA after exposure. There was no age difference in the accumulation of protein carbonyls for any age. The DNA damage of ER 15 or 30 days was different. The exposed neonates exhibited lower expression of catalase.950 MHz UHF EMR does not cause oxidative stress (OS), and it is not genotoxic to the livers of neonates or those of 6 and 15 day old rats, but it changes the concentrations of polyunsaturated fatty acid (PUFA) in neonates. For rats of 30 days, no OS, but it is genotoxic to the livers of ER to total body irradiation.

The glass-forming Nd 60 Fe 30 Al 10 alloy, processed by melt spinning, exhibits hard magnetic properties. For a relatively wide range of quenching rates, a single magnetic phase behavior is observed at room temperature, with coercivities between 0.1 and 0.4 T. As the quenching rate decreases, the hard magnetic properties improve and the thermal stability of the resulting magnetic microstructure—as measured by the reciprocal of the mean fluctuations field H f —decreases. The hysteresis and thermal relaxation properties observed for different cooling rates are discussed on the basis of domain wall movement in a ferromagnetic matrix in which small, highly anisotropic clusters develop as the quenching rate decreases.

We analyze the finite temperature phase diagram of ultrathin magnetic films by introducing a mean field theory, valid in the low anisotropy regime, i.e., close to de Spin Reorientation Transition. The theoretical results are compared with Monte Carlo simulations carried out on a microscopic Heisenberg model. Connections between the finite temperature behavior and the ground state properties of the system are established. Several properties of the stripes pattern, such as the presence of canted states, the stripes width variation phenomenon and the associated magnetization profiles are also analyzed., Comment: 9 pages, 8 figures

In this work we study the problem of targeting signals in networks using entropy information measurements to quantify the cost of targeting. We introduce a penalization rule that imposes a restriction to the long paths and therefore focus the signal to the target. By this scheme we go continuously from fully random walkers to walkers biased to the target. We found that the optimal degree of penalization is mainly determined by the topology of the network. By analyzing several examples, we have found that a small amount of penalization reduces considerably the typical walk length, and from this we conclude that a network can be efficiently navigated with restricted information., Comment: 9 pages, 11 figures

The dynamic Young modulus (E) of magnetic Nd2Fe14B+αFe nanocomposites is investigated with mechanical spectroscopy techniques (vibrating reed configuration, f≈1.5 kHz e ∼10 6 K/min ) and magneto-mechanical effects. Even when porosity is identified as the principal cause of modulus reduction, magnetic effects are also detected.

Ferromagnetic amorphous Nd 60 Fe 30 Al 10 alloys melt spun at wheel speeds between 5 and 20 m/s exhibit hard magnetic properties, which are found to be very sensitive to the cooling conditions. The magnetization reversion mechanisms leading to the rather high coercive forces found are investigated by thermally activated magnetic relaxation experiments; the mean fluctuation field and the activation volume are measured—in specimens cooled at different rates—at the critical field for extensive magnetization reversion. These preliminary results show a qualitative agreement with the predictions of a ferromagnetic cluster model.

We performed Monte Carlo simulations in a bilayer system composed by two thin films, one ferromagnetic (FM) and the other antiferromagnetic (AFM). Two lattice structures for the films were considered: simple cubic (sc) and a body center cubic (bcc). In both lattices structures we imposed an uncompensated interfacial spin structure, in particular we emulated a FeF2-FM system in the case of the (bcc) lattice. Our analysis focused on the incidence of the interfacial strength interactions between the films J_eb and the effect of thermal fluctuations on the bias field H_EB. We first performed Monte Carlo simulations on a microscopic model based on classical Heisenberg spin variables. To analyze the simulation results we also introduced a simplified model that assumes coherent rotation of spins located on the same layer parallel to the interface. We found that, depending on the AFM film anisotropy to exchange ratio, the bias field is either controlled by the intrinsic pinning of a domain wall parallel to the interface or by the stability of the first AFM layer (quasi domain wall) near the interface., Comment: 18 pages, 11 figures