Geometry in the Transition from Primary to Post-Primary

This article is intended as a kind of precursor to the document Geometry for Post-primary School Mathematics, part of the Mathematics Syllabus for Junior Certicate issued by the Irish National Council for Curriculum and Assessment in the context of Project Maths. Our purpose is to place that document in the context of an overview of plane geometry, touching on several important pedagogical and historical aspects, in the hope that this will prove useful for teachers.Comment: 19 page

Hierarchical priority setting for restoration in a watershed in NE Spain, based on assessments of soil erosion and ecosystem services

31 páginas[EN] Maintaining and enhancing ecosystem services through the restoration of degraded ecosystems have become an important biodiversity conservation strategy. Deciding where to restore ecosystems for the attainment of multiple services is a key issue for future planning, management, and human well-being. Most restoration projects usually entail a small number of actions in a local area and do not consider the potential benefits of planning restoration at broad regional scales. We developed a hierarchical priority setting approach to evaluate the performance of restoration measures in a semiarid basin in NE Spain (the Martín River Basin, 2,112 km2). Our analysis utilized a combination of erosion (a key driver of degradation in this Mediterranean region) and six spatially explicit ecosystem services data layers (five of these maps plotted surrogates for soil retention and accumulation, water supply and regulation, and carbon storage, and one plotted a cultural service, ecotourism). Hierarchical maps were generated using a geographic information system that combined areas important for providing a bundle of ecosystem services, as state variables, with erosion maps, as the disturbance or regulatory variable. This was performed for multiple scales, thereby identifying the most adequate scale of analysis and establishing a spatial hierarchy of restoration actions based on the combination of the evaluation of erosion rates and the provision of ecosystem services. Our approach provides managers with a straightforward method for determining the spatial distribution of values for a set of ecosystem services in relation to ecological degradation thresholds and for allocating efforts and resources for restoration projects in complex landscapes.This work was funded by Endesa S.A. through the collaborative agreement Endesa-CSIC for scientific research. The first author wants to thank Belinda Reyers for the fruitful conversation and helpfulness showed in every moment and two anonymous referees for their constructive suggestions. M. Trabucchi was in receipt of grant from JAE-DOC Program for Advanced Study financed by the European Social Fund (ESF), Ref. I3P-BPD-2006.Peer reviewe

The impact of hospital accreditation on quality measures:An interrupted time series analysis

BACKGROUND: Developing countries frequently use hospital accreditation to guarantee quality and patient safety. However, implementation of accreditation standards is demanding on organisations. Furthermore, the empirical literature on the benefits of accreditation is sparse and this is the first empirical interrupted time series analysis designed to examine the impact of healthcare accreditation on hospital quality measures. METHODS: The study was conducted in a 150-bed multispecialty hospital in Abu Dhabi, United Arab Emirates. The quality performance outcomes were observed over a 48 month period. The quality performance differences were compared across monthly intervals between two time segments, 1 year pre- accreditation (2009) and 3 years post-accreditation (2010, 2011 and 2012) for the twenty-seven quality measures. The principal data source was a random sample of 12,000 patient records drawn from a population of 50,000 during the study period (January 2009 to December 2012). Each month (during the study period), a simple random sample of 24 percent of patient records was selected and audited, resulting in 324,000 observations. The measures (structure, process and outcome) are related to important dimensions of quality and patient safety. RESULTS: The study findings showed that preparation for the accreditation survey results in significant improvement as 74% of the measures had a significant positive pre-accreditation slope. Accreditation had a larger significant negative effect (48% of measures) than a positive effect (4%) on the post accreditation slope of performance. Similarly, accreditation had a larger significant negative change in level (26%) than a positive change in level (7%) after the accreditation survey. Moreover, accreditation had no significant impact on 11 out of the 27 measures. However, there is residual benefit from accreditation three years later with performance maintained at approximately 90%, which is 20 percentage points higher than the baseline level in 2009. CONCLUSIONS: Although there is a transient drop in performance immediately after the survey, this study shows that the improvement achieved from accreditation is maintained during the three year accreditation cycle

Rho-dependent control of anillin behavior during cytokinesis

Anillin is a conserved protein required for cytokinesis but its molecular function is unclear. Anillin accumulation at the cleavage furrow is Rho guanine nucleotide exchange factor (GEF)Pbl–dependent but may also be mediated by known anillin interactions with F-actin and myosin II, which are under RhoGEFPbl-dependent control themselves. Microscopy of Drosophila melanogaster S2 cells reveal here that although myosin II and F-actin do contribute, equatorial anillin localization persists in their absence. Using latrunculin A, the inhibitor of F-actin assembly, we uncovered a separate RhoGEFPbl-dependent pathway that, at the normal time of furrowing, allows stable filamentous structures containing anillin, Rho1, and septins to form directly at the equatorial plasma membrane. These structures associate with microtubule (MT) ends and can still form after MT depolymerization, although they are delocalized under such conditions. Thus, a novel RhoGEFPbl-dependent input promotes the simultaneous association of anillin with the plasma membrane, septins, and MTs, independently of F-actin. We propose that such interactions occur dynamically and transiently to promote furrow stability

Ecosystem goods and services in semi-arid lanscape : an examination of the relationship between ecological processes, land-use strategies and biodiversity conservation

[page 80, 121, 137, x2; 20, 156 missing] Biodiversity loss and the disruption and degradation of ecosystems is proceeding at unprecedented rates. Conservation areas are insufficient to protect all species and there is growing recognition of the need to promote biodiversity conservation on private land, through the adoption of biodiversity-friendly land-use practices. Conservation and ecosystem function are linked to the delivery of ecosystem goods and services, which are processes and conditions of ecosystems that benefit humans and their activities. The research focus on ecosystem goods and services to date has been at global and regional scales, and there is a paucity of research at the fine scale. Benefits need to be measured and evaluated at a fine scale if land-users are to adopt best practices. The central aim of this study was to examine the relationship between commercial agricultural land-use practices and ecosystem goods and services in a biodiversity hotspot in a semi-arid area of South Africa. The approach adopted was based on the premise that to influence management activities and land-use practices it is best to first develop an understanding of what farmers perceive to be the most important ecosystem goods and services and how they manage their landscapes according to these perceptions. Farmers recognise and value a broad range of ecosystem goods and services that they incorporate into their farming practices, and their management framework is structured according to these in an attempt to optimise production. Ecosystem goods and services are perceived according to landscape heterogeneity which provides temporal and spatial opportunities for their exploitation. An exploration of the effects of land-use practices on identified ecosystem goods and services showed these to be highly dependent on the incorporation of natural vegetation and the maintenance of key ecological processes. Natural vegetation is essential for the provision of goods and services related to grazing and livestock production, with different vegetation types providing different goods and services. The maintenance of the service provided by an abundance of small mammals as an alternative source of prey to livestock for medium-sized predators, was demonstrated to be highly dependent upon landscape and vegetation structure, with 82% of all mammals trapped in the most structurally diverse vegetation type, vegetation clearance resulted in a seven fold decrease in small mammal abundance. A detailed examination of rainfall infiltration and erosion in natural, transformed and managed transformed vegetation showed there to be greater infiltration, less run-off, wind speeds reduced four fold, and eight times less soil lost to wind erosion in natural vegetation compared with transformed areas. However, in managed transformed areas, rainfall infiltration was greater than in natural and transformed areas. An examination of the key ecological processes maintaining soil health showed a decline in 1 soil invertebrate activity with increasing distance from natural vegetation remnants. However, under managed transformed conditions earthworm populations were three times greater than in natural vegetation remnants and this may account for greater infiltration rates measured here. An exploration of the potential to develop horticultural products from the species in the area, demonstrated the importance of the retention of natural vegetation as repositories of future-use options. In comparing farmers' perceptions, with analysed ecosystem goods and services, their perceptions were demonstrated to be generally accurate in their identification of ecosystem goods and services. While their perceptions may be correct, the value farmers place on a particular service is often not sufficient to influence fanning practice. Farmers appear to misjudge the degree of magnitude that management effects have on the delivery of ecosystem goods and services. Despite farmers perceiving the general concept of future-use options, they do not perceive the repository potential of their own remnant patches of natural vegetation for ecosystem goods. The broader objective of this thesis has been to consider the role that an understanding of ecosystem goods and services can play in promoting biodiversity conservation on private agricultural land. While scientists grapple with the conceptual issue of how diversity links to ecosystem processes, whether all species are important, and finally how these may benefit humans, farmers work at a mdre intuitive level trying to achieve benefits for themselves based on their experiences and perceptions, which influence land strategies. As a result, understanding farmers' perceptions and testing some of their assumptions can provide a basis for illustrating the links between biodiversity and goods and services at a farm level and in this way offer opportunities for conservation on private land

Mitotic Regulators Govern Progress through Steps in the Centrosome Duplication Cycle

Centrosome duplication is marked by discrete changes in centriole structure that occur in lockstep with cell cycle transitions. We show that mitotic regulators govern steps in centriole replication in Drosophila embryos. Cdc25string, the expression of which initiates mitosis, is required for completion of daughter centriole assembly. Cdc20fizzy, which is required for the metaphase-anaphase transition, is required for timely disengagement of mother and daughter centrioles. Stabilization of mitotic cyclins, which prevents exit from mitosis, blocks assembly of new daughter centrioles. Common regulation of the nuclear and centrosome cycles by mitotic regulators may ensure precise duplication of the centrosome

Temporal lobe (TL) damage following surgery and high-dose photon and proton irradiation in 96 patients affected by chordomas and chondrosarcomas of the base of the skull

Purpose: To determine the temporal lobe (TL) damage rate in 96 patients treated with high-dose proton and photon irradiation for chordomas and chondrosarcomas of the base of the skull. Methods and Materials: The records of 96 consecutive patients treated at Massachusetts General Hospital (MGH) and Harvard Cyclotron Laboratory (HCL) between June 1984 and 1993, for chordomas and chondrosarcomas of the base of the skull were reviewed. All the patients had undergone some degree of resection of the tumor prior to radiation therapy. Seventy-five patients were classified as 'primary tumors' and 21 as recurrent or regrowing tumors after one or more surgical procedures. All the patients were randomized to receive 66.6 or 72 cobalt Gray equivalent (CGE) on a prospective dose-searching study by proton and photon irradiation (Radiation Therapy Oncology Group No.85-26) with conventional fractionation (1.8 CGE/day, 5 fractions/week). All treatments were planned using the three-dimensional (3D) planning system developed at the Massachusetts General Hospital, and the dose was delivered using opposed lateral fields for the photon component and a noncoplanar isocentric technique for the proton component. Clinical symptoms of TL damage were classified into 4 grades. Computerized tomography (CT) and magnetic resonance imaging (MRI) scans were evaluated for white matter changes. Abnormalities associated with persistent or recurrent tumor were distinguished from radiation-induced changes. TLs were delineated on the original scans of the 10 patients with damage and those of a group of 33 patients with no clinical or MRI evidence of injury. Dose distributions were calculated and dose- volume histograms were obtained for these patients. Results: Of the patients, 10 developed TL damage, with bilateral injury in 2 and unilateral injury in 8. The cumulative TL damage incidence at 2 and 5 years was 7.6 and 13.2%, respectively. The MRI areas suggestive of TL damage were always separated from the tumor bed. Symptoms were severe to moderate in 8 patients. Several baseline factors, tumor- or host-related, were analyzed to evaluate their predictivity for TL damage: age, gender, tumor site, histology, type of presentation, type and number of surgical procedures, primary tumor volume, prescribed dose, normal tissue involvement, and volume of TL receiving doses ranging between 10 and 50 CGE or more. Only gender, in a univariate analysis (log rank) was a significant predictor of damage (0.0155), with male patients being at significantly higher risk of TL injury. In a stepwise Cox regression that included gender as a variable, no other baseline variable improved the prediction of damage. Conclusions: The 2- and 5-year cumulative TL damage rates were 7.6 and 13.2%, respectively. Despite the different TL damage rates related to age, tumor volume, number of surgical procedures prior to radiation therapy, and prescribed doses to the tumor, only gender was a significant predictor of damage (p = 0.0155) using a univariate (log rank) test. Chordomas and chondrosarcomas of the base of the skull may represent an interesting model to evaluate the TL damage rates because of their extradural origin, displacing the white matter instead of infiltrating it as gliomas do, because of their longer local recurrence-free survival other than gliomas and other brain tumors and because of the high doses of irradiation delivered to the target volume to obtain local control

Involvement of an SCF(Slmb) complex in timely elimination of E2F upon initiation of DNA replication in Drosophila

BACKGROUND: Cul1 is a core component of the evolutionarily conserved SCF-type ubiquitin ligases that target specific proteins for destruction. SCF action contributes to cell cycle progression but few of the key targets of its action have been identified. RESULTS: We found that expression of the mouse Cul1 (mCul1) in the larval wing disc has a dominant negative effect. It reduces, but does not eliminate, the function of SCF complexes, promotes accumulation of Cubitus interruptus (a target of SCF action), triggers apoptosis, and causes a small wing phenotype. A screen for mutations that dominantly modify this phenotype showed effective suppression upon reduction of E2F function, suggesting that compromised downregulation of E2F contributes to the phenotype. Partial inactivation of Cul1 delayed the abrupt loss of E2F immunofluorescence beyond its normal point of downregulation at the onset of S phase. Additional screens showed that mild reduction in function of the F-box encoding gene slimb enhanced the mCul1 overexpression phenotype. Cell cycle modulation of E2F levels is virtually absent in slimb mutant cells in which slimb function is severely reduced. This implicates Slimb, a known targeting subunit of SCF, in E2F downregulation. In addition, Slimb and E2F interacted in vitro in a phosphorylation-dependent manner. CONCLUSION: We have used genetic and physical interactions to identify the G1/S transcription factor E2F as an SCF(Slmb )target in Drosophila. These results argue that the SCF(Slmb )ubiquitin ligase directs E2F destruction in S phase

Selections that isolate recombinant mitochondrial genomes in animals.

Homologous recombination is widespread and catalyzes evolution. Nonetheless, its existence in animal mitochondrial DNA is questioned. We designed selections for recombination between co-resident mitochondrial genomes in various heteroplasmic Drosophila lines. In four experimental settings, recombinant genomes became the sole or dominant genome in the progeny. Thus, selection uncovers occurrence of homologous recombination in Drosophila mtDNA and documents its functional benefit. Double-strand breaks enhanced recombination in the germline and revealed somatic recombination. When the recombination partner was a diverged Drosophila melanogaster genome or a genome from a different species such as Drosophila yakuba, sequencing revealed long continuous stretches of exchange. In addition, the distribution of sequence polymorphisms in recombinants allowed us to map a selected trait to a particular region in the Drosophila mitochondrial genome. Thus, recombination can be harnessed to dissect function and evolution of mitochondrial genome