Malan: a mapping language for the data manipulation

Malan is a MApping LANguage that allows the generation of transformation programs by specifying a schema mapping between a source and target data schema. By working at the schema level, Malan remains independent of any transformation process; it also naturally guarantees the correctness of the transformation target relative to its schema. Moreover, by expressing schemas as UML class diagrams, Malan schema mappings can be written on top of UML modellers. This paper describes the overall approach by focusing on the Malan language itself, and its use within a transformation process

Un tour d'horizon des approches pour la manipulation des données du web

Le passage au web 2.0 a renforcé le principe selon lequel les données doivent être séparées de leurs présentations. En même temps, le nombre des formats de documents XML a largement évolué sur le web. Les bases de données sont également utilisées pour le fonctionnement des sites. Ces constats impliquent la mise en œuvre d’approches et d’outils associés dédiés à la manipulation des données du web. Certaines de ces approches travaillent directement sur les données, tandis que d’autres se basent sur les schémas de ces mêmes données. L’ingénierie dirigée par les modèles (IDM) forme également une approche candidate à la manipulation des données du web. Dans cet article, nous présentons et comparons les différentes techniques majeures de manipulation de données afin de mettre en exergue leurs avantages et leurs inconvénients pour le problème des données du web

Population Structure and Conservation Genetics of the Oregon Spotted Frog, Rana Pretiosa

The Oregon spotted frog (Rana pretiosa) is one of the most threatened amphibians in the Pacific Northwest. Here we analyzed data from 13 microsatellite loci and 298 bp of mitochondrial DNA in frogs collected from 23 of the remaining R. pretiosa populations in order to (1) assess levels of genetic diversity within populations of R. pretiosa, (2) identify the major genetic groups in the species, (3) estimate levels of genetic differentiation and gene flow among populations within each major group, and (4) compare the pattern of differentiation among R. pretiosa populations with that among populations of R. cascadae, a non-endangered congener that also occurs in Oregon and Washington. There is a strong, hierarchical genetic structure in R. pretiosa. That structure includes six major genetic groups, one of which is represented by a single remaining population. R. pretiosa populations have low genetic diversity (average He = 0.31) compared to R. cascadae (average He = 0.54) and to other ranid frogs. Genetic subdivision among populations is much higher in R. pretiosa than in R. cascadae, particularly over the largest geographic distances (hundreds of kilometers). A joint analysis of migration rates among populations and of effective sizes within populations (using MIGRATE) suggests that both species have extremely low migration rates, and that R. pretiosa have slightly smaller effective sizes. However, the slight difference in effective sizes between species appears insufficient to explain the large difference in genetic diversity and in large-scale genetic structure. We therefore hypothesize that low connectivity among the more widely-spaced R. pretiosa populations (owing to their patchier habitat), is the main cause of their lower genetic diversity and higher among-population differentiation. Conservation recommendations for R. pretiosa include maintaining habitat connectivity to facilitate gene flow among populations that are still potentially connected, and either expanding habitat or founding additional \u27backup\u27 populations to maintain diversity in the isolated populations. We recommend that special consideration be given to conservation of the Camas Prairie population in Northern Oregon. It is the most geographically isolated population, has the lowest genetic diversity (He = 0.14) and appears to be the only remaining representative of a major genetic group that is now almost extinct. Finally, because the six major groups within R. pretiosa are strongly differentiated, occupy different habitat types, and are geographically separate, they should be recognized as evolutionarily significant units for purposes of conservation planning

The Incentives for Tax Planning

We use a proprietary data set with detailed executive compensation information to examine the relationship between the incentives of the tax director and GAAP and cash effective tax rates, the book-tax gap, and measures of tax aggressiveness. We find that the incentive compensation of the tax director exhibits a strong negative relationship with the GAAP effective tax rate, but little relationship with the other tax attributes. We interpret these results as indicating that tax directors are provided with incentives to reduce the level of tax expense reported in the financial statements

Balance task and head orientation dependency of vestibular reflexes in neck muscles

Human upright posture of both the head and body is facilitated by the CNS’s ability to integrate multiple sensory feedback signals, as well as its discernibility of the motor commands that maintain this stabilization. The vestibular organ in particular detects motion of the head-in-space, which is transformed according to on-going head and body orientation into appropriate motor responses. However, when motor commands do not contribute to the control of standing posture, and are incongruent with their expected sensory consequences, vestibulomuscular responses in the lower limb undergo unconscious suppression. In this study, we investigated whether vestibular response suppression occurs in neck muscles under conditions where the muscles are active but not engaged in a task to balance the head. In addition, we examined the effects of head orientation to identify spatial transformation of vestibular reflex responses. Eight subjects were exposed to stochastic vestibular stimulation (0-75 Hz) in a seated condition while their head was either free or fixed, and rotated at either 0 or 60°. In head-free conditions, subjects were asked to rotate their head 60° to the left in order to activate agonist neck muscle pairs (sternocleidomastoid - SCM and splenius capitis - SPL). In head-fixed conditions, subjects performed isometric neck muscle contractions in yaw at orientations of 0° and 60°, as well as flexion, extension and co-contraction at an orientation of 0°. Intramuscular EMG was collected bilaterally in SCM and SPL muscles. Muscle responses correlated to the input stimuli were significant (P < 0.05) for all conditions provided the muscle was used in contraction. Neither muscle underwent the expected vestibulomuscular suppression when not engaged in the balance task (i.e. head-fixed). Nevertheless, the magnitude of the SPL responses decreased by 22% when the head was fixed whereas SCM responses were unaffected. The effect of head fixation only in SPL suggests differences in neural pathways across muscles, possibly via alternative pathways known to exist in the SPL from the well-established monosynaptic vestibulospinal inputs in SCM and SPL. For both muscles, the effect of orientation and force direction had no effect on muscles responses. Since the stimulation is fixed relative to the head, the same muscles are activated to respond to the input stimulus at both orientations and all force directions. These results indicate that the vestibular pathways connecting neck muscles are less susceptible to suppression than lower limb muscles, most likely because the monosynaptic inputs innervating them are subject to less central control

Vestibular contributions to lateral stabilization are bilaterally dependent during split belt walking

Vestibular information is critical for maintaining balance during locomotion, and is known to be attenuated with increasing locomotor velocity and cadence. This attenuation is muscle and phase dependent, and is thought to reflect the functional contribution of each muscle to balance control during each stride of the gait cycle. Bilaterally, the vestibular coupling is mirrored relative to the gait cycle as each leg undergoes similar modulation with variation in phase, velocity and cadence. Here, we asked whether the modulation of the vestibular contribution to each limb is bilaterally dependent. By using a split-belt treadmill with asymmetric belt speeds, we can control the locomotion properties of each leg and compare the vestibular modulation to symmetric conditions. We hypothesized that bilaterally symmetric vestibular modulation would indicate leg independent vestibular influence while bilaterally asymmetric vestibular modulation would indicate leg dependent vestibular influence. Subjects were exposed to binaural bipolar stochastic vestibular stimulation (0-25 Hz) during symmetric and asymmetric walking conditions. Symmetric trials were performed at belt speeds of 0.4 and 0.8 m/s and for 10 min. The asymmetric trial was performed at belt speeds of 0.4 and 0.8 m/s for 16 min. Subjects walked with a cadence of 78 steps/min which was easily maintained in both limbs. EMG of the bilateral medial gastrocnemii and three-dimensional ground reaction force and torques were collected. Only the last 340 strides (~ 9 min of data) were used in the analysis to avoid the adaptation that typically occurs within the first 250 strides (~ 6 min) of asymmetric walking. Significant muscle activity and lateral ground reaction forces (P < 0.01) were correlated to the input stimuli in all trials. Stimulus-EMG and -lateral ground reaction force correlations decreased at higher belt speeds during symmetric walking, as previously reported. During the split belt condition, the magnitude of correlations stimulus-EMG and -force were bilaterally asymmetric and different from their symmetric counterparts. During the asymmetric condition correlations decreased for the slow leg, but more closely resembled the responses observed during slow symmetric walking, and increased for the fast leg, but more closely resembled the responses observed during fast symmetric walking. These results indicate that the modulation of vestibular reflexes is dependent upon the specific kinematics of each leg but bilaterally linked to respond to the properties of the locomotion pattern

A double-blind randomized controlled trial of maternal postpartum deworming to improve infant weight gain in the Peruvian Amazon

Background : Nutritional interventions targeting the critical growth and development period before two years of age can have the greatest impact on health trajectories over the life course. Compelling evidence has demonstrated that interventions investing in maternal health in the first 1000 days of life are beneficial for both mothers and their children. One such potential intervention is deworming integrated into maternal postpartum care in areas where soil-transmitted helminth (STH) infections are endemic. Methodology/Principal Findings : From February to August 2014, 1010 mother-infant pairs were recruited into a trial aimed at assessing the effectiveness of maternal postpartum deworming on infant and maternal health outcomes. Following delivery, mothers were randomly assigned to receive either single-dose 400 mg albendazole or placebo. Participants were followed-up at 1 and 6 months postpartum. There was no statistically significant difference in mean weight gain between infants in the experimental and control groups (mean difference: -0.02; 95% CI: -0.1, 0.08) at 6 months of age. Further, deworming had no effect on measured infant morbidity indicators. However, ad hoc analyses restricted to mothers who tested positive for STHs at baseline suggest that infants of mothers in the experimental group had greater mean length gain in cm (mean difference: 0.8; 95% CI: 0.1, 1.4) and length-for-age z-score (mean difference: 0.5; 95% CI: 0.2, 0.8) at 6 months of age. Conclusions/Significance : In a study population composed of both STH-infected and uninfected mothers, maternal postpartum deworming was insufficient to impact infant growth and morbidity indicators up to 6 months postpartum. Among STH-infected mothers, however, important improvements in infant length gain and length-for-age were observed. The benefits of maternal postpartum deworming should be further investigated in study populations having higher overall prevalences and intensities of STH infections and, in particular, where whipworm and hookworm infections are of public health concern

Corporate Governance, Incentives, and Tax Avoidance

We examine the link between corporate governance, managerial incentives, and corporate tax avoidance. Similar to other investment opportunities that involve risky expected cash flows, unresolved agency problems may lead managers to engage in more or less corporate tax avoidance than shareholders would otherwise prefer. Consistent with the mixed results reported in prior studies, we find no relation between various corporate governance mechanisms and tax avoidance at the conditional mean and median of the tax avoidance distribution. However, using quantile regression, we find a positive relation between board independence and financial sophistication for low levels of tax avoidance, but a negative relation for high levels of tax avoidance. These results indicate that these governance attributes have a stronger relation with more extreme levels of tax avoidance, which are more likely to be symptomatic of over- and under-investment by managers