Promoting core maths - background, evidence, plans, opportunities, and challenges

This article discusses some of the issues relating to the promotion of Core Maths to students, parents, schools and colleges and their senior leadership teams, and also to employers and higher education (HE). Some challenges are highlighted, and addressed, with suggestions for ways forward to secure the future of Core Maths and widespread adoption by all stakeholders. A summary of the background reports that led to the introduction of Core Maths, and the related educational landscape prior to its introduction, is included.

Late Quaternary environmental change in the interior South American tropics: new insight from leaf wax stable isotopes

Stable isotope analysis of leaf waxes in a sediment core from Laguna La Gaiba, a shallow lake located at the Bolivian margin of the Pantanal wetlands, provides new perspective on vegetation and climate change in the lowland interior tropics of South America over the past 40,000 years. The carbon isotopic compositions (δ13C) of long-chain n-alkanes reveal large shifts between C3-and C4-dominated vegetation communities since the last glacial period, consistent with landscape reconstructions generated with pollen data from the same sediment core. Leaf wax δ13C values during the last glacial period reflect an open landscape composed of C4grasses and C3herbs from 41–20ka. A peak in C4abundance during the Last Glacial Maximum (LGM, ∼21ka) suggests drier or more seasonal conditions relative to the earlier glacial period, while the development of a C3-dominated forest community after 20 ka points to increased humidity during the last deglaciation. Within the Holocene, large changes in the abundance of C4 vegetation indicate a transition from drier or more seasonal conditions during the early/mid-Holocene to wetter conditions in the late Holocene coincident with increasing austral summer insolation. Strong negative correlations between leaf wax δ13C and δD values over the entire record indicate that the majority of variability in leaf wax δD at this site can be explained by variability in the magnitude of biosynthetic fractionation by different vegetation types rather than changes in meteoric water δD signatures. However, positive δD deviations from the observed δ13C–δD trends are consistent with more enriched source water and drier or more seasonal conditions during the early/mid-Holocene and LGM. Overall, our record adds to evidence of varying influence of glacial boundary conditions and orbital forcing on South American Summer Monsoon precipitation in different regions of the South American tropics. Moreover, the relationships between leaf wax stable isotopes and pollen data observed at this site underscore the complementary nature of pollen and leaf wax δ13C data for reconstructing past vegetation changes and the potentially large effects of such changes on leaf wax δD signatures.

Effects of Cadmium on the Rat Salivary Glands, During Lactation

Cadmium (Cd) in air, drinking water and food has the potential to affect the health of people, mainly those who live in highly industrialized regions. Cd affects placental function, can cross the placental barrier and directly modify fetal development. Once the organism is particularly susceptible to the exposition to the Cd during the perinatal period, and that this metal can be excreted in the milk, the aim of the present work was to study the effects of the constant exposition to drinkable water containing low levels of Cd during the lactation, on the salivary glands of the rat. Female rats received ad libitum drinking water containing 300mg/l of CdCl2 throughout the whole lactation. Control animals received a similar volume of water without Cd. Lactant rats (21 day old) were killed by lethal dose of anesthetic. The salivary glands were separated, fixed in ""alfac"" solution for 24 h, and serially sectioned. The 6 mu m thick sections were stained with hematoxylin and eosin. Nuclear glandular parameters were estimated, as well as cytoplasm and cell volume, nucleus/cytoplasm ratio, number and surface density, diameters and cell thickness. Mean body weight was 34.86 g for the control group and 18.56 g for the Cd-treated group. Histologically, the glandular acini were significantly smaller, the gland ducts were similar in both groups studied. The connective tissue was more abundant. In conclusion, the salivary glands (submandibular, parotid and sublingual) showed retarded growth after Cd intoxication.

CHANDRA AND SPITZER IMAGING OF THE INFRARED CLUSTER IN NGC 2071

We present results of a sensitive Chandra X-ray observation and Spitzer mid-infrared (mid-IR) observations of the IR cluster lying north of the NGC 2071 reflection nebula in the Orion B molecular cloud. We focus on the dense cluster core known as NGC 2071-IR, which contains at least nine IR sources within a 40 `` x 40 `` region. This region shows clear signs of active star formation including powerful molecular outflows, Herbig-Haro objects, and both OH and H(2)O masers. We use Spitzer Infrared Array Camera (IRAC) images to aid in X-ray source identification and to determine young stellar object (YSO) classes using mid-IR colors. Spitzer IRAC colors show that the luminous source IRS 1 is a class I protostar. IRS 1 is believed to be driving a powerful bipolar molecular outflow and may be an embedded B-type star or its progenitor. Its X-ray spectrum reveals a fluorescent Fe emission line at 6.4 keV, arising in cold material near the protostar. The line is present even in the absence of large flares, raising questions about the nature of the ionizing mechanism responsible for producing the 6.4 keV fluorescent line. Chandra also detects X-ray sources at or near the positions of IRS 2, IRS 3, IRS 4, and IRS 6 and a variable X-ray source coincident with the radio source VLA 1, located just 2 `` north of IRS 1. No IR data are yet available to determine a YSO classification for VLA 1, but its high X-ray absorption shows that it is even more deeply embedded than IRS 1, suggesting that it could be an even younger, less-evolved protostar.

Microhabitat Selection of three Forest Understory Birds in the Brazilian Atlantic Rainforest

When assessing fragmentation effects on species, not only habitat preferences on the landscape scale, but also microhabitat selection is an important factor to consider, as microhabitat is also affected by habitat disturbance, but nevertheless essential for species for foraging, nesting and sheltering. In the Atlantic Rainforest of Brazil we examined microhabitat selection of six Pyriglena leucoptera (white-shouldered fire-eye), 10 Sclerurus scansor (rufous-breasted leaftosser), and 30 Chiroxiphia caudata (blue manakin). We radio-tracked the individuals between May 2004 and February 2005 to gain home ranges based on individual fixed kernels. Vegetation structures in core plots and fringe plots were compared. In C. caudata, we additionally assessed the influence of behavioural traits on microhabitat selection. Further, we compared microhabitat structures in the fragmented forest with those in the contiguous, and contrasted the results with the birds` preferences. Pyriglena leucoptera preferred liana tangles that were more common in the fragmented forest, whereas S. scansor preferred woody debris, open forest floor (up to 0.5 m), and a thin closed leaf litter cover which all occurred significantly more often in the contiguous forest. Significant differences were detected in C. caudata for vegetation densities in the different strata; the distance of core plots to the nearest lek site was significantly influenced by sex and age. However, core sites of C. caudata in fragmented and contiguous forests showed no significant differences in structure. Exploring microhabitat selection and behavior may greatly support the understanding of habitat selection of species and their susceptibility to fragmentation on the landscape scale.

The CATH Hierarchy Revisited-Structural Divergence in Domain Superfamilies and the Continuity of Fold Space

This paper explores the structural continuum in CATH and the extent to which superfamilies adopt distinct folds. Although most superfamilies are structurally conserved, in some of the most highly populated superfamilies (4% of all superfamilies) there is considerable structural divergence. While relatives share a similar fold in the evolutionary conserved core, diverse elaborations to this core can result in significant differences in the global structures. Applying similar protocols to examine the extent to which structural overlaps occur between different fold groups, it appears this effect is confined to just a few architectures and is largely due to small, recurring super-secondary motifs (e.g., alpha beta-motifs, alpha-hairpins). Although 24% of superfamilies overlap with superfamilies having different folds, only 14% of nonredundant structures in CATH are involved in overlaps. Nevertheless, the existence of these overlaps suggests that, in some regions of structure space, the fold universe should be seen as more continuous.

High female mortality resulting in herd collapse in free-ranging domesticated reindeer (Rangifer tarandus tarandus) in Sweden

Reindeer herding in Sweden is a form of pastoralism practised by the indigenous Sami population. The economy is mainly based on meat production. Herd size is generally regulated by harvest in order not to overuse grazing ranges and keep a productive herd. Nonetheless, herd growth and room for harvest is currently small in many areas. Negative herd growth and low harvest rate were observed in one of two herds in a reindeer herding community in Central Sweden. The herds (A and B) used the same ranges from April until the autumn gathering in October-December, but were separated on different ranges over winter. Analyses of capture-recapture for 723 adult female reindeer over five years (2007-2012) revealed high annual losses (7.1% and 18.4%, for herd A and B respectively). A continuing decline in the total reindeer number in herd B demonstrated an inability to maintain the herd size in spite of a very small harvest. An estimated breakpoint for when herd size cannot be kept stable confirmed that the observed female mortality rate in herd B represented a state of herd collapse. Lower calving success in herd B compared to A indicated differences in winter foraging conditions. However, we found only minor differences in animal body condition between the herds in autumn. We found no evidence that a lower autumn body mass generally increased the risk for a female of dying from one autumn to the next. We conclude that the prime driver of the on-going collapse of herd B is not high animal density or poor body condition. Accidents or disease seem unlikely as major causes of mortality. Predation, primarily by lynx and wolverine, appears to be the most plausible reason for the high female mortality and state of collapse in the studied reindeer herding community.

Reuse-based test planning for core-based systems-on-chip

Electronic applications are currently developed under the reuse-based paradigm. This design methodology presents several advantages for the reduction of the design complexity, but brings new challenges for the test of the final circuit. The access to embedded cores, the integration of several test methods, and the optimization of the several cost factors are just a few of the several problems that need to be tackled during test planning. Within this context, this thesis proposes two test planning approaches that aim at reducing the test costs of a core-based system by means of hardware reuse and integration of the test planning into the design flow. The first approach considers systems whose cores are connected directly or through a functional bus. The test planning method consists of a comprehensive model that includes the definition of a multi-mode access mechanism inside the chip and a search algorithm for the exploration of the design space. The access mechanism model considers the reuse of functional connections as well as partial test buses, cores transparency, and other bypass modes. The test schedule is defined in conjunction with the access mechanism so that good trade-offs among the costs of pins, area, and test time can be sought. Furthermore, system power constraints are also considered. This expansion of concerns makes it possible an efficient, yet fine-grained search, in the huge design space of a reuse-based environment. Experimental results clearly show the variety of trade-offs that can be explored using the proposed model, and its effectiveness on optimizing the system test plan. Networks-on-chip are likely to become the main communication platform of systemson- chip. Thus, the second approach presented in this work proposes the reuse of the on-chip network for the test of the cores embedded into the systems that use this communication platform. A power-aware test scheduling algorithm aiming at exploiting the network characteristics to minimize the system test time is presented. The reuse strategy is evaluated considering a number of system configurations, such as different positions of the cores in the network, power consumption constraints and number of interfaces with the tester. Experimental results show that the parallelization capability of the network can be exploited to reduce the system test time, whereas area and pin overhead are strongly minimized. In this manuscript, the main problems of the test of core-based systems are firstly identified and the current solutions are discussed. The problems being tackled by this thesis are then listed and the test planning approaches are detailed. Both test planning techniques are validated for the recently released ITC’02 SoC Test Benchmarks, and further compared to other test planning methods of the literature. This comparison confirms the efficiency of the proposed methods.

Sexual blinging of women : Alice Walker's african character tashi and issue of female genital cutting

This thesis provides a reading of the different forms of representation that can be attributed to the character Tashi, the protagonist of the novel Possessing the Secret of Joy (1992), written by the African American writer Alice Walker. Before this work Tashi had already appeared in two previous novels by Walker, first, in The Color Purple (1982) and then, as a mention, in The Temple of My Familiar (1989). With Tashi, the author introduces the issue of female circumcision, a ritual Tashi submits herself to at the beginning of her adult life. The focus of observation lies in the ways in which the author’s anger is transformed into a means of creative representation. Walker uses her novel Possessing the Secret of Joy openly as a political instrument so that the expression “female mutilation” (term used by the author) receives ample attention from the media and critics in general. The aim of this investigation is to evaluate to what extent Walker’s social engagement contributes to the development of her work and to what extent it undermines it. For the analysis of the different issues related to “female genital cutting”, the term I use in this thesis, the works of feminist critics and writers such as Ellen Gruenbaum, Lightfoot-Klein, Nancy Hartsock, Linda Nicholson, Efrat Tseëlon and the Egyptian writer and doctor Nawal El Saadawi will be consulted. I hope that this thesis can contribute as an observation about Alice Walker’s use of her social engagement in the creation of her fictional world.

The effects of gender segregation at the establishment level: an empirical analysis using a panel of matched employer-employee data

This paper studies the relationship between segregation of women across establish- ments and the wages of males and females. To investigate this issue empirically we use a panel of matched employer-employee data from Brazil. Various longitudinal models are used to assess the wage impact of establishment gender segregation. Overall, the results indicate that the e ect of establishment female proportion on the wages of males and females is negative. We also compare these longitudinal results with cross-section estimates, which are the usual ones obtained in the related literature. This com- parison suggests that unmeasured, time-invariant worker- and establishment-speci c e ects are correlated with the establishment female composition.

Transplacental transmission of Toxoplasma gondii in reinfected pregnant female canines

Twelve pregnant female canines, naturally infected with Toxoplasma gondii, were reinfected with T. gondii: three (GI) received tachyzoites subcutaneously (1.0 x 107), three (GII) were orally inoculated with oocysts (1.5 x 104), and six (GIII) were kept as a nonreinfected control group. All the reinfected female canines (GI and GII) miscarried or presented fetal death, while only one GIII female presented a stillborn in a litter of four pups (P < 0.01). Fever, lymphoadenopathy, miscarriage, and fetal death were the main clinical alterations observed. The highest serological titers detected through the indirect fluorescence antibody test (IFAT) were 1,024 (GI) and 4,096 (GII). In group III, the titers ranged between 64 and 256. By bioassays in mice, T. gondii was isolated in 17 organs of the reinfected adult canines, in 11 of the control group, and in 20 of the neonates. Positive immunostaining of cysts and/or tachyzoites were observed in 26 canine tissues (14 from GI and GII and ten from GIII). The agent was detected by immunohistochemistry in the encephalon of a neonate and in the spinal cord of a stillborn, thus, confirming that T. gondii infected canine fetuses, provoking miscarriages, even in bitches that presented primoinfection.

Functional morphology of adult female Culex quinquefasciatus midgut during blood digestion

The adult female Culex quinquefasciatus midgut comprises a narrow anterior and a dilated posterior region, with epithelia composed of a monolayer of adjacent epithelial cells joined at the apical portion by septate junctions. Densely packed apical microvilli and an intricate basal labyrinth characterise each cell pole. Our morphological studies suggest that, during blood digestion, the anterior midgut region also participates in an initial absorptive stage which is probably related to the intake of water, salts and other small molecules. This activity peaked by 6 h after bloodmeal feeding (ABF) and ended approximately 18 h ABF, when the peritrophic membrane was already formed. After this time, absorption only occurred in the posterior region, with morphologic and biochemical evidence of high synthetic activity related to the secretion of proteases. Chymotrypsin, elastase, aminopeptidase, and trypsin reached their maximum activity at around 36 h ABF. Digestion products were apparently absorbed and transported to the basal labyrinth, from where they should be released to the hemolymph. At 72 h ABF, proteolysis had already ended and protein levels had returned to those observed before blood meal. The epithelium of the posterior region, however, did not return to its initial morphology, appearing quite disorganised. Additionally, from 48 h ABF onwards some epithelial cells showed morphological signals of apoptosis. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

Sugar digestion in mosquitoes: Identification and characterization of three midgut alpha-glucosidases of the neo-tropical malaria vector Anopheles aquasalis (Diptera : Culicidae)

Dietary carbohydrates provide an important source of energy for flight, and contribute to longevity and fecundity of mosquitoes. The most common sugar mosquitoes ingest is sucrose, and digestion of this substance is carried out mainly by alpha-glucosidases. In the current work, we tested the efficiency of sucrose on Anopheles aquasalis female diet. The best longevity (days) was reached when sugar was available in the diet, whereas most only blood fed females were dead 6 days after emergence. Three alpha-glucosidase isoforms were detected in the adult female midgut, named alpha Glu1, alpha Glu2 and alpha Glu3. These are acidic alpha-glucosidases with optima pH around pH 5.5. alpha Glu1 and alpha Glu2 are present in both secreted and membrane-bound forms, whereas alpha Glu3 only in anchored to membranes. The alpha-glucosidase activity is concentrated mainly in the posterior midgut (70%), both in non-fed or 10% sucrose fed females. The single form of these a-glucosidases seemed to be similar to 70 kDa polypeptides, although alpha Glu2 is presented in >= 600 kDa self-aggregates. K, values of alpha Glu1, alpha Glu2 and alpha Glu3 differed significantly from each other, supporting the statement that three alpha-glucosidases are produced in the female midgut. Together, all data suggest that sugar is an essential component of A. aquasalis female diet. In addition, alpha-glucosidases are synthesized in the same place where sucrose is digested and absorbed, the midgut. (c) 2007 Elsevier B.V. All rights reserved.

A new Brazilian species of the cricket genus Megalogryllus Chopard (Orthoptera: Gryllidae)

Megalogryllus clamosus, uma nova espécie de grilo do estado de São Paulo, é descrita. As fotografias do holótipo (macho) e do parátipo (fêmea) são apresentadas, assim como o desenho do tégmen direito do macho e a estrutura fálica. As fotografias da pars stridens para mostrar a estrutura dos dentes e o sonograma do canto de chamado do macho são também apresentados.

Iron Oxide Versus Fe55Pt45/Fe3O4: Improved Magnetic Properties of Core/Shell Nanoparticles for Biomedical Applications

In this paper, synthesis of the Fe55Pt45/Fe3O4 core/shell structured nanoparticles using the modified polyol process combined with the seed-mediated growth method is reported. Iron oxide shell thickness was tuned controlling the Fe(acac)(3)/FePt seeds in the reaction medium. Annealing of the core/shell structure leads to iron-rich layer formation around the hard FePt phase in the nanoparticle core. However, the 2 nm Fe3O4 shell thickness seems to be the limit to obtain the enhanced magnetization close to the alpha-Fe and preserving an iron oxide shell after annealing at 500 degrees C for 30 min in a reducing atmosphere. The presence of both the oxide layer on nanoparticle surface and an intermediate iron-rich FePt layer after annealing promote strong decreases in the coercive field of the 2-nm-oxide shell thickness. These annealed nanoparticles were functionalized with dextran, presenting the enhanced characteristics for biomedical applications such as higher magnetization, very low coercivity, and a slightly iron oxide passivated layer, which leads an easy functionalization and decreases the nanoparticle toxicity.