MonetDB/XQuery: a fast XQuery processor powered by a relational engine

Relational XQuery systems try to re-use mature relational data management infrastructures to create fast and scalable XML database technology. This paper describes the main features, key contributions, and lessons learned while implementing such a system. Its architecture consists of (i) a range-based encoding of XML documents into relational tables, (ii) a compilation technique that translates XQuery into a basic relational algebra, (iii) a restricted (order) property-aware peephole relational query optimization strategy, and (iv) a mapping from XML update statements into relational updates. Thus, this system implements all essential XML database functionalities (rather than a single feature) such that we can learn from the full consequences of our architectural decisions. While implementing this system, we had to extend the state-of-the-art with a number of new technical contributions, such as loop-lifted staircase join and efficient relational query evaluation strategies for XQuery theta-joins with existential semantics. These contributions as well as the architectural lessons learned are also deemed valuable for other relational back-end engines. The performance and scalability of the resulting system is evaluated on the XMark benchmark up to data sizes of 11GB. The performance section also provides an extensive benchmark comparison of all major XMark results published previously, which confirm that the goal of purely relational XQuery processing, namely speed and scalability, was met

Effect of nocturnal grazing and supplementation on diet selection, eating time, forage intake and weight changes of cattle

Sixty-four Azawak male calves were used to study the effect of nocturnal grazing (NG) and supplementation (S) in the dry season on forage and water intake, faecal output, eating time and weight changes of cattle in the Sahel. Treatments were factorial combinations of four levels of NG (0, 2, 4 and 6 h/day) and two levels of S (0 and 608 g dry matter (DM) per animal per day). All animals were allowed to graze 10 h during the day and were weighed every 2 weeks during the 70-day experimental period. Eight oesophageally fistulated steers were used in a cross-over design to sample the diet (forage) selected during the day and at night by supplemented and non-supplemented animals. Extrusa crude protein and in vitro organic matter digestibility were not influenced by supplementation (P > 0.05). Time spent eating during the day or at night were not affected by supplementation but total eating time increased by 39.4 (s.e. 2.1) min/h of NG. Forage intake increased with increase in NG, while total food intake (forage supplement) increased with supplementation (82.4 v. 92.1 (s.e. 2.4) g DM per kg M0.75 per day). The supplemented animals also drank more water than the non-supplemented (26.2 v. 24.8 l per animal per day). Average live-weight change (LWC) increased by 24.4 (s.e. 8.7) and 9.3 (s.e. 6.2) g/h of NG in non-supplemented and supplemented animals, respectively. Supplementation improved LWC (-107 v. 99 g/day, s.e. 14, P < 0.05). Night grazing improves dry season performance and its effect decreases when cattle are supplemented

Cerebellar induced differential polyglot aphasia: a neurolinguistic and fMRI study

Research has shown that linguistic functions in the bilingual brain are subserved by similar neural circuits as in monolinguals, but with extra-activity associated with cognitive and attentional control. Although a role for the right cerebellum in multilingual language processing has recently been acknowledged, a potential role of the left cerebellum remains largely unexplored. This paper reports the clinical and fMRI findings in a strongly right-handed (late) multilingual patient who developed differential polyglot aphasia, ataxic dysarthria and a selective decrease in executive function due to an ischemic stroke in the left cerebellum. fMRI revealed that lexical-semantic retrieval in the unaffected L1 was predominantly associated with activations in the left cortical areas (left prefrontal area and left postcentral gyrus), while naming in two affected non-native languages recruited a significantly larger bilateral functional network, including the cerebellum. It is hypothesized that the left cerebellar insult resulted in decreased right prefrontal hemisphere functioning due to a loss of cerebellar impulses through the cerebello-cerebral pathways