QR Codes in Education

QR codes, developed by a Japanese company, have been around for over fifteen years. With the advent of smart and Web capable mobile devices, we witness a steady growth of interesting commercial applications using QR codes. As the movement of using QR codes in education is still in its infancy, this paper serves to be one of the first comprehensive papers in journal publication to fully delineate (a) the user characteristics of QR codes, (b) the processes of making and reading QR codes, (c) the survey of commercial applications using QR codes, (d) the literature review of educational applications using QR codes, and (e) offer suggestions and implementations of QR codes in school education

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Dominância fiscal : uma investigação empírica sobre o caso brasileiro no período de 2003 a 2014

A estabilização econômica dos anos de 1990 e a adoção do tripé econômico, a partir de 1999, marcam o fim de um capítulo delicado da história brasileira; a partir de então, era necessária a existência de certa sintonia de políticas monetária e fiscal para a manutenção do controle dos diversos indicadores econômicos. Contudo, com essa reciprocidade na política econômica, são incitadas discussões sobre a orientação do governo na hora de definir suas prioridades nesse campo: as variáveis fiscais são priorizadas e, por conseguinte, determinadas, forçando as monetárias a se ajustarem – ou o contrário? A resposta para esse questionamento leva à discussão sobre a dominância fiscal. Assim, esse trabalho visa verificar empiricamente, usando das modelagens econométricas VAR e estudo de eventos, se há dominância fiscal ou monetária na economia brasileira e se a eficácia da política monetária mudou na transição do governo Lula para o governo Dilma. O resultado foi inconclusivo para o governo Lula e indicou dominância fiscal no governo Dilma. Ainda verificou-se não haver modificação na eficácia da política monetária.Economic stabilization, in the 1990s, and utilization of an economic tripod, after 1999, represents the end of a delicate chapter in Brazilian history. Ever since, it was necessary the existence of a certain agreement between monetary and fiscal politic, in order to maintain under control a variety of economic indicators. However, this reciprocity (in economic politic) starts discussions about the real government orientations when it comes to define its priority on this subject: are the fiscal variables priorized, and then, determined, forcing monetary variables to adjust themselves, or the opposite? The answer to these questions emerge from the fiscal dominance discussion. This paper intends to empiric verify, using econometric modeling VAR and event study, if there is fiscal dominance or monetary in Brazilian economy and whether the effectiveness of monetary politic has changed in the transition from Lula's government to the Dilma government. The result was inconclusive for the Lula government and indicated fiscal dominance in the Dilma government. There was still no change in the efficiency of the monetary politic.CAPE

Incorporation of Silver-Doped Graphene Oxide Quantum Dots in Polyvinylidene Fluoride Membrane for Verapamil Removal

Verapamil hydrochloride, a calcium channel-blocking agent, is detectable in receiving water bodies and affects the well-being of aquatic organisms. Membrane filtration could be effective in removing such pharmaceutical contaminants. However, limited studies have employed commercial membranes, such as polyvinylidene fluoride (PVDF), in removing verapamil from water sources, owing to their low solution fluxes, poor antibacterial properties, and high surface hydrophobicity. Efforts are needed to create the PVDF membrane suitable for removing verapamil from water sources. In this study, PVDF composite membranes incorporated with from 0 to 0.10 wt% silver-doped graphene oxide quantum dots (Ag−GOQD) were evaluated in terms of their morphological structures, elemental composition, surface roughness, hydrophilicity, verapamil rejection capability, anti-fouling, and antibacterial capabilities. The pure PVDF membrane showed the lowest verapamil rejection (73.66 ± 2.45%), highest surface roughness (mean surface roughness, Sa = 123.80 nm), and least hydrophilic membrane surface (contact angle = 79.06 ± 4.53°) when compared to other membranes incorporated with nanocomposites. However, the membrane incorporated with 0.10 wt% Ag−GOQD showed the smoothest and the most hydrophilic membrane surface (Sa = 13.10 nm and contact angle = 53.60 ± 4.75°, respectively), associated with the highest verapamil rejection (96.04 ± 1.82%). A clear inhibition zone was spotted in the agar plate containing the membrane incorporated with Ag−GOQD, showing the antibacterial capability of the membrane. The overall improvement in morphological structures, surface smoothness, surface hydrophilicities, permeabilities, verapamil rejection abilities, and anti-fouling and antibacterial capabilities indicated a great potential to incorporate Ag−GOQD in PVDF membrane fabrication

Incorporation of Silver-Doped Graphene Oxide Quantum Dots in Polyvinylidene Fluoride Membrane for Verapamil Removal

Verapamil hydrochloride, a calcium channel-blocking agent, is detectable in receiving water bodies and affects the well-being of aquatic organisms. Membrane filtration could be effective in removing such pharmaceutical contaminants. However, limited studies have employed commercial membranes, such as polyvinylidene fluoride (PVDF), in removing verapamil from water sources, owing to their low solution fluxes, poor antibacterial properties, and high surface hydrophobicity. Efforts are needed to create the PVDF membrane suitable for removing verapamil from water sources. In this study, PVDF composite membranes incorporated with from 0 to 0.10 wt% silver-doped graphene oxide quantum dots (Ag−GOQD) were evaluated in terms of their morphological structures, elemental composition, surface roughness, hydrophilicity, verapamil rejection capability, anti-fouling, and antibacterial capabilities. The pure PVDF membrane showed the lowest verapamil rejection (73.66 ± 2.45%), highest surface roughness (mean surface roughness, Sa = 123.80 nm), and least hydrophilic membrane surface (contact angle = 79.06 ± 4.53°) when compared to other membranes incorporated with nanocomposites. However, the membrane incorporated with 0.10 wt% Ag−GOQD showed the smoothest and the most hydrophilic membrane surface (Sa = 13.10 nm and contact angle = 53.60 ± 4.75°, respectively), associated with the highest verapamil rejection (96.04 ± 1.82%). A clear inhibition zone was spotted in the agar plate containing the membrane incorporated with Ag−GOQD, showing the antibacterial capability of the membrane. The overall improvement in morphological structures, surface smoothness, surface hydrophilicities, permeabilities, verapamil rejection abilities, and anti-fouling and antibacterial capabilities indicated a great potential to incorporate Ag−GOQD in PVDF membrane fabrication

A Coding System With Independent Annotations Of Gesture Forms And Functions During Verbal Communication: Development Of A Database Of Speech And Gesture (Dosage)

Gestures are commonly used together with spoken language in human communication. One major limitation of gesture investigations in the existing literature lies in the fact that the coding of forms and functions of gestures has not been clearly differentiated. This paper first described a recently developed Database of Speech and GEsture based on independent annotation of gesture forms and functions among 119 neurologically unimpaired right-handed native speakers of Cantonese (divided into three age and two education levels), and presented findings of an investigation examining how gesture use was related to age and linguistic performance. Consideration of these two factors, for which normative data are currently very limited or lacking in the literature, is relevant and necessary when one evaluates gesture employment among individuals with and without language impairment. Three speech tasks, including monologue of a personally important event, sequential description, and story-telling, were used for elicitation. The EUDICO Linguistic ANnotator software was used to independently annotate each participant’s linguistic information of the transcript, forms of gestures used, and the function for each gesture. About one-third of the subjects did not use any co-verbal gestures. While the majority of gestures were non-content-carrying, which functioned mainly for reinforcing speech intonation or controlling speech flow, the content-carrying ones were used to enhance speech content. Furthermore, individuals who are younger or linguistically more proficient tended to use fewer gestures, suggesting that normal speakers gesture differently as a function of age and linguistic performance