A Picture is Worth a Thousand Words: Understanding our Students' Mathematical Experiences through Drawing

Learning about our students’ perceptions of mathematics can help teachers better understand students’ mathematical efficacy and aid in the creation of lessons that foster positive mathematical learning experiences. In this article, we share some students’ perceptions of doing mathematics through their drawings. We looked at students from three different grade levels in three different countries: China, Fiji, and the United States. We discuss what we learned from these drawings as teachers and how teachers can use the drawing task to learn more about their student’s perceptions of doing mathematics

CLC channel function and dysfunction in health and disease

CLC channels and transporters are expressed in most tissues and fulfill diverse functions. There are four human CLC channels, ClC-1, ClC-2, ClC-Ka and ClC-Kb, and five CLC transporters, ClC-3 through -7. Some of the CLC channels additionally associate with accessory subunits. Whereas barttin is mandatory for the functional expression of CLC-K, GlialCam is a facultative subunit of ClC-2 which modifies gating and thus increases the functional variability within the CLC family. Isoform-specific ion conduction and gating properties optimize distinct CLC channels for their cellular tasks. ClC-1 preferentially conducts at negative voltages, and the resulting inward rectification provides a large resting chloride conductance without interference with the muscle action potential. Exclusive opening at voltages negative to the chloride reversal potential allows for ClC-2 to regulate intracellular chloride concentrations. ClC-Ka and ClC-Kb are equally suited for inward and outward currents to support transcellular chloride fluxes. Every human CLC channel gene has been linked to a genetic disease, and studying these mutations has provided much information about the physiological roles and the molecular basis of CLC channel function. Mutations in the gene encoding ClC-1 cause myotonia congenita, a disease characterized by sarcolemmal hyperexcitability and muscle stiffness. Loss-of-function of ClC-Kb/barttin channels in patients suffering from Bartter syndrome identified the determinants of chloride conductances in the limb of Henle. Mutations in CLCN2 were found in patients with CNS disorders but the functional role of this isoform is still not understood. Recent links between ClC-1 and epilepsy and ClC-Ka and heart failure suggested novel cellular functions of these proteins. This review aims to survey the knowledge about physiological and pathophysiological functions of human CLC channels in the light of recent discoveries from biophysical, physiological and genetic studies

HYACINTH MACAWS (ANODORHYNCHUS HYACINTHINUS, PSITTACIDAE) FEEDING ON TERMITES

Abstract ∙ Hyacinth Macaws (Anodorhynchus hyacinthinus) feed largely on palm seeds and fruits. Here, we report a pair of Hyacinth Macaws feeding on termites. We visited the nesting tree of a pair of Hyacinth Macaws at the southern border of the Brazilian Pantanal on a monthly basis during one year. Macaws were present during four of these visits, and we recorded them foraging on arboreal termites in their nesting tree during one of the visits. Using their beaks, both macaw individuals repeatedly broke away bark pieces from decaying branches, and handled them with beak and feet to ingest termites found on the inner side of the bark. Nesting in decaying trees likely increases opportunities for Hyacinth Macaws to find termites, and the feeding behavior of these macaws indicates that they are familiar with and able to consume termites. This is the first report of termite consumption by this species.Resumo ∙ Arara‐azul‐grande (Anodorhynchus hyacinthinus, Psittacidae) comendo cupins Indivíduos de Arara‐azul‐grande (Anodorhynchus hyacinthinus) consomem principalmente sementes de palmeiras e frutos. Reportamos aqui um casal de Araras‐azuis‐grandes consumindo cupins. Visitamos uma árvore de nidificação na borda sul do Pantanal brasileiro mensalmente durante um ano. As araras estavam presentes em quatro visitas, e registramos consumo de cupins presentes na árvore de nidificação em uma visita. As araras repetidamente retiravam com o bico pedaços de casca de ramos podres, e manuseavam os pedaços com o bico e os pés para ingerir cupins presentes na parte interna da casca. Nidificar em árvores senescentes provavelmente aumenta a oportunidade dessas araras encontrarem cupins, e o comportamento alimentar delas indica familiaridade e habilidade em consumilos. Esse é o primeiro registro de consumo de cupins por esta espécie.

Entwicklung neuer multimerer PET-Tracer zur verbesserten Diagnostik von Prostatakarzinomen

Die nuklearmedizinischen Bildgebungsverfahren erlangen weltweit immer größere Bedeutung. Insbesondere die Positronen-Emissions-Tomographie (PET) wird in zunehmendem Maße häufiger eingesetzt, was zur Folge hat, dass es einen steigenden Bedarf an Tracern für diagnostische Untersuchungen gibt. Jedoch steht nur eine begrenzte Anzahl von PET-Tracern für Untersuchungen zur Verfügung und oft haben diese Tracer den Nachteil, dass sie sich nicht gut genug im Zielgewebe anreichern. Mittels Multimerisierung lassen sich diverse Eigenschaften von biologisch aktiven Substanzen verbessern, weshalb die Multimerisierung in dieser Arbeit zur Herstellung von PET-Tracern mit verbesserten Bindungseigenschaften untersucht wurde. Im ersten Teil dieser Arbeit wurde zunächst eine neue Synthesestrategie entwickelt, mit dem multimere Grundgerüste (Dendrone), die sich für die Herstellung multivalenter PET-Tracer eignen, hergestellt werden können. Mit dieser Synthesestrategie ist es möglich Dendrone bis zur Größe eines Hexadezimers einfach und schnell herzustellen und es konnte gezeigt werden, dass die Dendrone durch Einbringung verschiedener Oligoethylenglycol-Linker in ihrem Aufbau flexibel verändert werden können. In diese Dendrone wurde zusätzlich der Chelator DOTA, mit dem sich das PET-Nuklid 68Ga in die Multimere einführen lässt, oder eine Thiol-tragende Aminosäure, über die beliebige Moleküle eingeführt werden können, mit eingebracht. Anschließend wurden testweise verschiedene bioaktive Moleküle sowie DOTA multimerisiert, wobei die Dendrone als Grundgerüst dienten. Die dadurch erhaltenen multivalenten Substanzen wurden mit 68Ga radiomarkiert, um die Anwendbarkeit des Ansatzes für die Herstellung von PET-Radiotracern zu belegen. Im zweiten Teil dieser Arbeit wurden neue bivalente, Prostatakarzinom-affine PET-Radiopharmaka hergestellt. Diese Substanzen enthielten zwei Bombesin-Analoga (BBN(7-14)), die an die Gastrin Releasing Peptide (GRP)-Rezeptoren binden, und den Chelator NODAGA, über den sich das PET-Nuklid 68Ga ebenfalls in Substanzen einführen lässt. In die dimeren BBN(7-14)-Analoga wurden zusätzlich verschieden lange Ethylenglycol-Linker eingebracht, wodurch insgesamt fünf BBN(7‒14)-Dimere mit einem unterschiedlich großen Abstand zwischen den BBN(7‒14)-Peptiden erhalten werden konnten. Diese BBN(7‒14)-Dimere wurden im weiteren Verlauf der Arbeit in in vitro-Bindungsstudien an einer GRP-Rezeptor exprimierenden Prostata-Adenokarzinomzelllinie (PC3-Zellen) getestet, um den Einfluss des Abstandes der BBN(7‒14)-Peptide im Dimer auf die Bindungseigenschaften zu untersuchen. Das BBN(7‒14)-Dimer, dass in vitro die besten Bindungseigenschaften besaß, wurde anschließend zusammen mit der monomeren Vergleichssubstanz DOTA-PESIN und dem Dimer DOTA-(PESIN)2 in vivo an PC3-tumortragenden Nacktmäusen getestet. Diese Mäuse wurden mittels PET-CT untersucht, womit der Nachweis erbracht werden sollte, dass sich die verbesserten Bindungseigenschaften des neuen BBN(7‒14)-Dimers auch positiv auf das Anreichungsverhalten im Tumor auswirken.The nuclear medicine imaging is a diagnostic tool of increasing importance and especially the Positron Emission Tomography (PET) is used more frequently, which causes a growing demand for new PET-tracers. However, there is only a limited number of PET-tracers available, and in addition, these tracers often exhibit a poor accumulation behavior in the target-tissue. The multimerization of biological active compounds is a promising alternative to improve the imaging characteristics, and this is why the multimerization was considered in this thesis for the production of new PET-tracers with improved imaging properties. In the first part of this work, a new synthesis strategy was developed, which allows the assembly of multimeric frameworks (dendrons), and which can be used for the production of multivalent PET-tracers. With this synthesis strategy, dendrons with up to 16 functionalities could efficiently be synthesized, and it could be shown, that these dendrons can flexibly be modified by inserting oligo ethylene glycol-linker (OEG) into the structure. Additionally, these dendrons were derivatized with the chelating agent DOTA, which allows the introduction of the PET-nuclide 68Ga to multimeric scaffolds, or a thiol-bearing amino-acid, by which arbitrary molecules can be introduced into the dendron-structure. Subsequently, DOTA as well as different bioactive compounds were multimerized, using the dendrons as scaffolds. Finally, to prove the applicability of the synthesis process, these multivalent compounds were radiolabelled with 68Ga. In the second part of this work, new bivalent and prostate cancer-affine PET-tracers were established. These compounds comprised two bombesin-analogs (BBN(7-14)), which are known for their affinity to gastrin releasing peptide (GRP)-receptors, as well as the chelator NODAGA, by which 68Ga can also be introduced into various substances. A total of five dimeric BBN(7-14)-analogs with ethylene glycol-linkers of different length ‒ to vary the distance between the BBN(7-14)-peptides ‒ , were obtained and tested in in vitro binding studies to analyze the influence of the BBN(7-14)-peptide distance in relation to the binding characteristics. At last, in vivo experiments were performed by the application of either the dimeric BBN(7-14)-analog, that exhibited the best binding characteristics in vitro, monomeric DOTA-PESIN (that was used as standard) or dimeric DOTA-(PESIN)2 to PC3-tumor-bearing nude mice. Subsequently, these mice were examined by PET-CT, to prove, that the advanced binding avidity of the newly developed dimeric BBN(7-14)-analog positively influences the accumulation in the tumor tissue

Entwicklung neuer multimerer PET-Tracer zur verbesserten Diagnostik von Prostatakarzinomen

Die nuklearmedizinischen Bildgebungsverfahren erlangen weltweit immer größere Bedeutung. Insbesondere die Positronen-Emissions-Tomographie (PET) wird in zunehmendem Maße häufiger eingesetzt, was zur Folge hat, dass es einen steigenden Bedarf an Tracern für diagnostische Untersuchungen gibt. Jedoch steht nur eine begrenzte Anzahl von PET-Tracern für Untersuchungen zur Verfügung und oft haben diese Tracer den Nachteil, dass sie sich nicht gut genug im Zielgewebe anreichern. Mittels Multimerisierung lassen sich diverse Eigenschaften von biologisch aktiven Substanzen verbessern, weshalb die Multimerisierung in dieser Arbeit zur Herstellung von PET-Tracern mit verbesserten Bindungseigenschaften untersucht wurde. Im ersten Teil dieser Arbeit wurde zunächst eine neue Synthesestrategie entwickelt, mit dem multimere Grundgerüste (Dendrone), die sich für die Herstellung multivalenter PET-Tracer eignen, hergestellt werden können. Mit dieser Synthesestrategie ist es möglich Dendrone bis zur Größe eines Hexadezimers einfach und schnell herzustellen und es konnte gezeigt werden, dass die Dendrone durch Einbringung verschiedener Oligoethylenglycol-Linker in ihrem Aufbau flexibel verändert werden können. In diese Dendrone wurde zusätzlich der Chelator DOTA, mit dem sich das PET-Nuklid 68Ga in die Multimere einführen lässt, oder eine Thiol-tragende Aminosäure, über die beliebige Moleküle eingeführt werden können, mit eingebracht. Anschließend wurden testweise verschiedene bioaktive Moleküle sowie DOTA multimerisiert, wobei die Dendrone als Grundgerüst dienten. Die dadurch erhaltenen multivalenten Substanzen wurden mit 68Ga radiomarkiert, um die Anwendbarkeit des Ansatzes für die Herstellung von PET-Radiotracern zu belegen. Im zweiten Teil dieser Arbeit wurden neue bivalente, Prostatakarzinom-affine PET-Radiopharmaka hergestellt. Diese Substanzen enthielten zwei Bombesin-Analoga (BBN(7-14)), die an die Gastrin Releasing Peptide (GRP)-Rezeptoren binden, und den Chelator NODAGA, über den sich das PET-Nuklid 68Ga ebenfalls in Substanzen einführen lässt. In die dimeren BBN(7-14)-Analoga wurden zusätzlich verschieden lange Ethylenglycol-Linker eingebracht, wodurch insgesamt fünf BBN(7‒14)-Dimere mit einem unterschiedlich großen Abstand zwischen den BBN(7‒14)-Peptiden erhalten werden konnten. Diese BBN(7‒14)-Dimere wurden im weiteren Verlauf der Arbeit in in vitro-Bindungsstudien an einer GRP-Rezeptor exprimierenden Prostata-Adenokarzinomzelllinie (PC3-Zellen) getestet, um den Einfluss des Abstandes der BBN(7‒14)-Peptide im Dimer auf die Bindungseigenschaften zu untersuchen. Das BBN(7‒14)-Dimer, dass in vitro die besten Bindungseigenschaften besaß, wurde anschließend zusammen mit der monomeren Vergleichssubstanz DOTA-PESIN und dem Dimer DOTA-(PESIN)2 in vivo an PC3-tumortragenden Nacktmäusen getestet. Diese Mäuse wurden mittels PET-CT untersucht, womit der Nachweis erbracht werden sollte, dass sich die verbesserten Bindungseigenschaften des neuen BBN(7‒14)-Dimers auch positiv auf das Anreichungsverhalten im Tumor auswirken.The nuclear medicine imaging is a diagnostic tool of increasing importance and especially the Positron Emission Tomography (PET) is used more frequently, which causes a growing demand for new PET-tracers. However, there is only a limited number of PET-tracers available, and in addition, these tracers often exhibit a poor accumulation behavior in the target-tissue. The multimerization of biological active compounds is a promising alternative to improve the imaging characteristics, and this is why the multimerization was considered in this thesis for the production of new PET-tracers with improved imaging properties. In the first part of this work, a new synthesis strategy was developed, which allows the assembly of multimeric frameworks (dendrons), and which can be used for the production of multivalent PET-tracers. With this synthesis strategy, dendrons with up to 16 functionalities could efficiently be synthesized, and it could be shown, that these dendrons can flexibly be modified by inserting oligo ethylene glycol-linker (OEG) into the structure. Additionally, these dendrons were derivatized with the chelating agent DOTA, which allows the introduction of the PET-nuclide 68Ga to multimeric scaffolds, or a thiol-bearing amino-acid, by which arbitrary molecules can be introduced into the dendron-structure. Subsequently, DOTA as well as different bioactive compounds were multimerized, using the dendrons as scaffolds. Finally, to prove the applicability of the synthesis process, these multivalent compounds were radiolabelled with 68Ga. In the second part of this work, new bivalent and prostate cancer-affine PET-tracers were established. These compounds comprised two bombesin-analogs (BBN(7-14)), which are known for their affinity to gastrin releasing peptide (GRP)-receptors, as well as the chelator NODAGA, by which 68Ga can also be introduced into various substances. A total of five dimeric BBN(7-14)-analogs with ethylene glycol-linkers of different length ‒ to vary the distance between the BBN(7-14)-peptides ‒ , were obtained and tested in in vitro binding studies to analyze the influence of the BBN(7-14)-peptide distance in relation to the binding characteristics. At last, in vivo experiments were performed by the application of either the dimeric BBN(7-14)-analog, that exhibited the best binding characteristics in vitro, monomeric DOTA-PESIN (that was used as standard) or dimeric DOTA-(PESIN)2 to PC3-tumor-bearing nude mice. Subsequently, these mice were examined by PET-CT, to prove, that the advanced binding avidity of the newly developed dimeric BBN(7-14)-analog positively influences the accumulation in the tumor tissue

Analysis of Health in Environmental Assessments:A Literature Review and Survey with a Focus on Denmark

In the European Union, the Environmental Impact Assessment (EIA) Directive (2014/52/EU) and Strategic Environmental Assessment (SEA) Directive (2011/92/EU) emphasise the assessment of population and human health. The directives require health to be considered within Environmental Impact Assessment (EIA) and Strategic Environmental Assessment (SEA). To date, health is mainly considered in connection with negative environmental factors and in terms of risk assessments. The integration of health in EIA as well as SEA has not been investigated in a Danish context, and this study aims to address the missing knowledge. There is a need for a more comprehensive health assessment within EIA and SEA to comply with the EIA and SEA directives. An integration of health into EIA and SEA will ensure a sound examination of health determinants which can improve decision making and thus comprehensively promote and protect health. To establish the status of the inclusion of the assessment of impacts on health into EIA and SEA, a literature review was performed. In addition, a survey addressed to researchers and practitioners was conducted and analysed through a comparative analysis. The survey examined the needs of practitioners and researchers, focusing on the Danish context, regarding the inclusion of health into EIA and SEA. Enhanced intersectoral cooperation of the health and environmental sectors, more specific guidance documents, and underlying this, stronger political support, were identified among needs for more comprehensive health assessments

Microbial Assemblages in Association with Crayfish Ectosymbionts

Undergraduat

Resistance of the Freshwater Microbiome to a Combination of Pesticides

Undergraduate Basi

Understanding Students\u27 Perceptions of Doing Mathematics: A Cultural Comparison

Garnering different kinds of data from students about their perceptions of mathematics helps teachers, teacher leaders, districts and researchers better understand students\u27 perceptions. In this study, we investigated and compared students’ perceptions of doing mathematics from samples of students from the United States, China, and Fiji. We administered the Draw Yourself Doing Mathematics instrument to students at three grade levels in China, Fiji, and the United States of America. Statistically significant differences among perceptions in the three countries and the three grade levels were observed. Student drawings were further analyzed for other qualitative components, including factors affecting the learning environment, such as the presence of desks and working with others. Discussion is provided about the instrument’s connection to other forms of perceptions research and implications for the use of the instrument by teachers, teacher leaders, and researchers

A Picture is Worth a Thousand Words: Understanding our Students\u27 Mathematical Experiences through Drawing

Learning about our students’ perceptions of mathematics can help teachers better understand students’ mathematical efficacy and aid in the creation of lessons that foster positive mathematical learning experiences. In this article, we share some students’ perceptions of doing mathematics through their drawings. We looked at students from three different grade levels in three different countries: China, Fiji, and the United States. We discuss what we learned from these drawings as teachers and how teachers can use the drawing task to learn more about their student’s perceptions of doing mathematics