Arithmetic fluency and number processing skills in identifying students with mathematical learning disabilities.

BACKGROUND: Students with mathematical learning disabilities (MLD) struggle with number processing skills (e.g., enumeration and number comparison) and arithmetic fluency. Traditionally, MLD is identified based on arithmetic fluency. However, number processing skills are suggested to differentiate low achievement (LA) from MLD. AIMS: This study investigated the accuracy of number processing skills in identifying students with MLD and LA, based on arithmetic fluency, and whether the classification ability of number processing skills varied as a function of grade level. METHODS AND PROCEDURES: The participants were 18,405 students (girls = 9080) from Grades 3-9 (ages 9-15). Students' basic numerical skills were assessed with an online dyscalculia screener (Functional Numeracy Assessment -Dyscalculia Battery, FUNA-DB), which included number processing and arithmetic fluency as two factors. OUTCOMES AND RESULTS: Confirmatory factor analyses supported a two-factor structure of FUNA-DB. The two-factor structure was invariant across language groups, gender, and grade levels. Receiver operating characteristics curve analyses indicated that number processing skills are a fair classifier of MLD and LA status across grade levels. The classification accuracy of number processing skills was better when predicting MLD (cut-off < 5 %) compared to LA (cut-off < 25 %). CONCLUSIONS AND IMPLICATIONS: Results highlight the need to measure both number processing and arithmetic fluency when identifying students with MLD.

Evaluation of VEGF-A and CCL2 in dogs with brachycephalic obstructive airway syndrome or canine idiopathic pulmonary fibrosis and in normocephalic dogs.

Brachycephalic obstructive airway syndrome (BOAS) and canine idiopathic pulmonary fibrosis (CIPF) of West Highland White Terriers (WHWTs) often cause intermittent or chronic hypoxemia. Our objective was to evaluate serum and bronchoalveolar lavage fluid (BALF) concentrations of hypoxemia-related proinflammatory mediators vascular endothelial growth factor A (VEGF-A) and chemokine (CC motif) ligand 2 (CCL2) in brachycephalic dogs (BDs) and WHWTs with and without CIPF. Additionally, effects of BOAS severity and ageing on these mediators were assessed. 114 BDs (28 English Bulldogs (EBs), 37 French Bulldogs, 49 Pugs), 16 WHWTs with CIPF, 26 healthy WHWTs, and 39 normocephalic control dogs were included. Fifty-four BDs were re-examined after two to three years. Bead-based immunoassay was used for proinflammatory mediator measurements. Compared with controls, significantly higher serum concentrations of VEGF-A were seen in EBs (P = 0.009) and of CCL2 in CIPF and healthy WHWTs (P < 0.001; P = 0.002). BALF samples were available from controls, EBs, and WHWTs. VEGF-A was significantly lower in EBs (P < 0.001) and in CIPF and healthy WHWTs (P = 0.006; P = 0.007) and CCL2 was higher in CIPF WHWTs (P = 0.01) compared with controls. Between visits, only serum VEGF-A significantly decreased in BDs (P < 0.001), but breed, BOAS severity, or its change had no significant effect. In conclusion, in EBs with BOAS proinflammatory changes in VEGF-A were detected in both serum and BALF. Ageing reduced serum VEGF-A in BDs. In WHWTs, our results confirmed earlier findings of CCL2 as an important biomarker for CIPF.

No Evidence of Herpesvirus Infection in West Highland White Terriers With Canine Idiopathic Pulmonary Fibrosis.

In humans, horses, and rodents, an association between pulmonary fibrotic disorders and gammaherpesvirus infection has been suggested. In dogs, canine idiopathic pulmonary fibrosis (CIPF), a progressive fibrotic lung disease of unknown origin and poorly understood pathophysiology, has been reported to occur in West Highland white terriers (WHWTs). The present study investigated the potential association between CIPF and herpesvirus infection. A PCR assay, using a mixture of degenerate and deoxyinosine-substituted primers targeting highly conserved regions of the DNA polymerase gene (DPOL) of herpesviruses, was applied on both lung and blood samples from WHWTs affected with CIPF and controls. Herpesvirus DPOL sequence could not be amplified from any of 46 lung samples (28 affected WHWTs and 18 control dogs of various breeds) and 38 blood samples (19 CIPF WHWTs and 19 control age-matched WHWTs) included. An association between CIPF and herpesvirus infection is therefore unlikely. Investigation of other causes of the disease is warranted.

Evaluation of chemokines CXCL8 and CCL2, serotonin, and vascular endothelial growth factor serum concentrations in healthy dogs from seven breeds with variable predisposition for canine idiopathic pulmonary fibrosis.

The West Highland white terrier (WHWT) is particularly prone to canine idiopathic pulmonary fibrosis (CIPF). We hypothesized that higher circulating concentrations of chemokines CXCL8, CCL2, serotonin (5-HT), or vascular endothelial growth factor (VEGF) could serve as predisposing factors for CIPF development in the WHWT breed. Serum samples from 103 healthy dogs of seven different breeds variably predisposed to CIPF were collected. Serum CXCL8 concentrations were higher in healthy WHWT compared with each of the other groups of healthy dogs. Serum CCL2 concentrations were higher in healthy WHWT and Maltese compared with King Charles spaniels and Malinois Belgian shepherds. No relevant inter-breed differences were observed for serum 5-HT concentrations regarding CIPF predisposition. VEGF values from 89.3% of samples tested were below the kit detection limit. In conclusion, high CXCL8 blood concentrations and possibly CCL2 concentrations might be related to the breed predisposition of the WHWT for CIPF and warrants further investigations.

Evaporation of ionic liquids at atmospheric pressure: study by ion mobility spectrometry.

A conventional ion mobility spectrometry (IMS) was used to study atmospheric pressure evaporation of seven pure imidazolium and pyrrolidinium ionic liquids (ILs) with [Tf(2)N], [PF(6)], [BF(4)] and [fap] anions. The positive drift time spectra of the as-received samples measured at 220°C exhibited close similarity; the peak at reduced mobility K(0)=1.99 cm(2)V(-1)s(-1) was a dominant spectral pattern of imidazolium-based ILs. With an assumption that ILs vapor consists mainly of neutral ion pairs, which generate the parent cations in the reactant section of the detector, and using the reference data on the electrical mobility of ILs cations and clusters, this peak was attributed to the parent cation [emim]. Despite visible change in color of the majority of ILs after the heating at 220°C for 5h, essential distinctions between spectra of the as-received and heated samples were not observed. In negative mode, pronounced peaks were registered only for ILs with [fap] anion.

An electrospray ionization Fourier transform ion cyclotron resonance mass spectrometric study of the gas-phase stabilities and fragmentation of N-alkylammonium resorcarenes.

Five N-alkylated ammonium resorcarene derivatives, differing either in the nitrogen atom or in the lower rim alkyl chain, were studied using electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. The main purpose was to clarify the fragmentation and the relative stabilities of the protonated molecules by collision-induced dissociation (CID) experiments. The results indicate that fragmentation of the upper rim alkyl amino substituents at the 2-position occurs readily. Variation in the gas-phase stabilities of these molecules was also observed. In addition, the proposed fragmentation pathways are depicted.

Ion-molecule reactions of 2-methoxyethanol with some amines, carboxylic acids and amino acids under chemical ionization conditions

2-Methoxyethanol chemical ionization of amines, carboxylic acids and amino acids has been found to produce numerous adduct ions. The most intense adduct ions for amines are [M + H](+) and [M + 77](+), for carboxylic acids [M + 27](+), [M + 59](+) and [M + 77](+), and for amino acids [M + H](+), [M + 13](+), [M + 27](+) and [M + 77](+). Either the adduct ion [M + H](+) or [M + 77](+) was the most abundant ion found for amino acids. The proton affinities of amino acids are noticed to control the formation of the [M + H](+) and [M + 77](+) ions. The relative abundance of [M + 13](+) and [M + 27](+) ions varied for different amino acids being most intense for phenylalanine and aspartic acid. Copyright 1999 John Wiley & Sons, Ltd.