The Landscape of US Elementary Mathematics Teacher Education: Course Requirements for Mathematics Content and Methods

The adequate preparation of future teachers of mathematics is critical, requiring sufficient opportunities to develop both pedagogical skill and content knowledge. Yet, despite new recommendations for mathematics teacher preparation, we know little about the landscape of course-based learning opportunities in US elementary teacher education programs. To what extent do US elementary teacher education programs meet the Standards for Preparing Teachers of Mathematics outlined by the Association of Mathematics Teacher Educators (AMTE) for mathematics content and methods courses? Based on an a priori power analysis, we gathered a random sample of 291 higher education institutions. Within these institutions, we analyzed 736 programs, including Bachelor’s, Master’s, and Credential programs. We found that overwhelmingly US elementary teacher education programs do not meet the aspirations outlined in the AMTE standards, with Master’s and Credential programs and those covering all elementary grades particularly falling short. Potential explanations for these challenges and implications for teacher education program design are discussed

Pathological and phylogenetic characterization of Amphibiothecum sp. infection in an isolated amphibian (Lissotriton helveticus) population on the island of Rum (Scotland)

Outbreaks of cutaneous infectious disease in amphibians are increasingly being attributed to an overlooked group of fungal-like pathogens, the Dermocystids. During the last 10 years on the Isle of Rum, Scotland, palmate newts (Lissotriton helveticus) have been reportedly afflicted by unusual skin lesions. Here we present pathological and molecular findings confirming that the pathogen associated with these lesions is a novel organism of the order Dermocystida, and represents the first formally reported, and potentially lethal, case of amphibian Dermocystid infection in the UK. Whilst the gross pathology and the parasite cyst morphology were synonymous to those described in a study from infected L. helveticus in France, we observed a more extreme clinical outcome on Rum involving severe subcutaneous oedema. Phylogenetic topologies supported synonymy between Dermocystid sequences from Rum and France and as well as their distinction from Amphibiocystidium spp. Phylogenetic analysis also suggested that the amphibian-infecting Dermocystids are not monophyletic. We conclude that the L. helveticusinfecting pathogen represents a single, novel species; Amphibiothecum meredithae

Psychometric properties of the Chinese version of the Eating Attitudes Test (EAT-26) in young female patients with eating disorders in mainland China

The study aimed to investigate the reliability and validity of the Chinese version of the eating attitudes test (EAT-26) among female adolescents and young adults in Mainland China. This scale was administered to 396 female eating disorder patients and 406 noneating disorder healthy controls, in addition 35 healthy controls completed a retest after a 4-week intervals. Tests for reliability, convergent validity and receiver operating characteristic analysis were performed to detect the psychometric properties. The EAT-26 demonstrated good internal consistency (Cronbach's alpha = 0.822–0.922), test–retest reliability (interclass correlation coefficient = 0.817) and convergent validity(r = 0.450–0.750). The receiver operating characteristic analysis showed that the cut-off 14 for anorexia nervosa and 15 for bulimia nervosa represented good compromises with approximate sensitivity (0.66–0.68) and specificity (0.85–0.86). Our findings provided evidence that the Chinese version of the EAT-26 was a psychometrically reliable and valid self-rating instrument for identifying people suffering from an eating disorder in Mainland China. A clinical cut-off range between 14 and 15 could be used, but caution should be exercised because of the low sensitivity of the tool

Deciphering interplay between Salmonella invasion effectors

Bacterial pathogens have evolved a specialized type III secretion system (T3SS) to translocate virulence effector proteins directly into eukaryotic target cells. Salmonellae deploy effectors that trigger localized actin reorganization to force their own entry into non-phagocytic host cells. Six effectors (SipC, SipA, SopE/2, SopB, SptP) can individually manipulate actin dynamics at the plasma membrane, which acts as a ‘signaling hub’ during Salmonella invasion. The extent of crosstalk between these spatially coincident effectors remains unknown. Here we describe trans and cis binary entry effector interplay (BENEFIT) screens that systematically examine functional associations between effectors following their delivery into the host cell. The results reveal extensive ordered synergistic and antagonistic relationships and their relative potency, and illuminate an unexpectedly sophisticated signaling network evolved through longstanding pathogen–host interaction

Evidence for directional selection at a novel major histocompatibility class I marker in wild common frogs (Rana temporaria) exposed to a viral pathogen (Ranavirus).

(c) 2009 Teacher et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Whilst the Major Histocompatibility Complex (MHC) is well characterized in the anuran Xenopus, this region has not previously been studied in another popular model species, the common frog (Rana temporaria). Nor, to date, have there been any studies of MHC in wild amphibian host-pathogen systems. We characterise an MHC class I locus in the common frog, and present primers to amplify both the whole region, and specifically the antigen binding region. As no more than two expressed haplotypes were found in over 400 clones from 66 individuals, it is likely that there is a single class I locus in this species. This finding is consistent with the single class I locus in Xenopus, but contrasts with the multiple loci identified in axolotls, providing evidence that the diversification of MHC class I into multiple loci likely occurred after the Caudata/Anura divergence (approximately 350 million years ago) but before the Ranidae/Pipidae divergence (approximately 230 mya). We use this locus to compare wild populations of common frogs that have been infected with a viral pathogen (Ranavirus) with those that have no history of infection. We demonstrate that certain MHC supertypes are associated with infection status (even after accounting for shared ancestry), and that the diseased populations have more similar supertype frequencies (lower F(ST)) than the uninfected. These patterns were not seen in a suite of putatively neutral microsatellite loci. We interpret this pattern at the MHC locus to indicate that the disease has imposed selection for particular haplotypes, and hence that common frogs may be adapting to the presence of Ranavirus, which currently kills tens of thousands of amphibians in the UK each year

Effects of resistance training protocols on nonlinear analysis of heart rate variability in metabolic syndrome

Besides some non-linear measurements used in autonomic modulation (AM) analysis can be suitable using short term series, they usually depend on long time-series of data. To transpose this, chaotic global methods were formulated, putting together heart rate variability (HRV) linear methods. Chaos provides information about vegetative function control related to cardiovascular risks. Applying this method to investigate the complexity of the health condition after resistance training protocols, used as a therapeutic intervention, on AM in metabolic syndrome individuals (MetS) is important. This study aimed to compare the effects of two resistance training programs (conventional vs. functional) in MetS using nonlinear analysis of AM. MetS subjects (n=50), both sexes, aged 40 to 60 years were randomized between two programs. Also, there was a control group (n=12). Both groups performed 30 sessions of training. AM was accessed in chaos domain by chaotic global techniques. The main results showed that both resistance training, functional and conventional, increased chaos when compared to the control group, respectively observed by CFP1 (13.9±17.9 vs. 12.8±14.4 vs. -2.23±7.96; p≤0.05) and CFP3 (15.4±19.8 vs. 21.9±13.2 vs. -4.82±11.4; p≤0.05). In addition, 30 sessions of both resistance programs increase chaos, and nonlinear analysis enables discriminates AM after interventions when compared to control group

In vitro characterisation of fresh and frozen sex-sorted bull spermatozoa

peer-reviewedThis study sought to compare the in vitro characteristics of fresh and frozen non-sorted (NS) and sex-sorted (SS) bull spermatozoa. Experiment 1: Holstein–Friesian ejaculates (n = 10 bulls) were split across four treatments and processed: (1) NS fresh at 3 × 106 spermatozoa, (2) X-SS frozen at 2 × 106 spermatozoa, (3) X-SS fresh at 2 × 106 spermatozoa and (4) X-SS fresh at 1 × 106 spermatozoa. NS frozen controls of 20 × 106 spermatozoa per straw were sourced from previously frozen ejaculates (n = 3 bulls). Experiment 2: Aberdeen Angus ejaculates (n = 4 bulls) were split across four treatments and processed as: (1) NS fresh 3 × 106 spermatozoa, (2) Y-SS fresh at 1 × 106 spermatozoa, (3) Y-SS fresh at 2 × 106 spermatozoa and (4) X-SS fresh at 2 × 106 spermatozoa. Controls were sourced as per Experiment 1. In vitro assessments for progressive linear motility, acrosomal status and oxidative stress were carried out on Days 1, 2 and 3 after sorting (Day 0 = day of sorting. In both experiments SS fresh treatments had higher levels of agglutination in comparison to the NS fresh (P < 0.001), NS frozen treatments had the greatest PLM (P < 0.05) and NS spermatozoa exhibited higher levels of superoxide anion production compared with SS spermatozoa (P < 0.05). Experiment 1 found both fresh and frozen SS treatments had higher levels of viable acrosome-intact spermatozoa compared with the NS frozen treatments (P < 0.01).ACCEPTEDpeer-reviewe