Opportunities and Challenges of Urban Agriculture for Sustainable City Development

Urban Agriculture (UA) has gained popularity in cities all over the world. In this paper, we explore the concept of UA and discuss it along various locational and strategic dimensions. The article aims to provide insights into the chances and challenges of UA for sustainable city development. By making use of case examples from cities worldwide we show that UA can contribute to the social, environmental, and economics pillars of sustainable city development. However, there are limitations which should be taken into account for cities that want to invest in urban agriculture

Novel microstructures and technologies applied in chemical analysis techniques

Novel glass and silicon microstructures and their application in chemical analysis are presented. The micro technologies comprise (deep) dry etching, thin layer growth and anodic bonding. With this combination it is possible to create high resolution electrically isolating silicon dioxide structures with aspect ratio's similar to those possible in silicon. Main applications are chemical separation methods such as high performance liquid chromatography (HPLC) or electrophoresis (HPCE). Beside these channel structures, a capillary connector with very low dead and mixing volume has been designed and fabricated for use in (correlation) electrophoresis, and tested by means of precision of consecutive single injection

Charge density mapping in a pediatric patient with symptomatic runs of ectopic atrial tachycardia

Ectopic atrial tachycardia (AT) poses a notable challenge in pediatric cardiology, often requiring precise localization for optimal treatment. Its incidence is relatively low, affecting 3.7%–5.7% of children undergoing electrophysiological studies.1 While catheter ablation complements pharmacological therapy, achieving a high success rate of approximately 90%, there is room for enhancement.1 A challenge lies in mapping and ablating transient episodes of AT. Recent innovations in mapping technologies, notably charge density mapping, have shown promise in providing precise single-beat noncontact mapping of transient AT in adult patients.2,3 This mapping technique uses individualized anatomy of a heart chamber, created by ultrasound crystals that are integrated in a basket catheter, with subsequent visualization of recorded cardiac dipoles.4 This article explores a unique case with short runs of ectopic AT, demonstrating the efficacy of single-beat noncontact mapping using charge density mapping in a pediatric patient

Charge density mapping in a pediatric patient with symptomatic runs of ectopic atrial tachycardia

Ectopic atrial tachycardia (AT) poses a notable challenge in pediatric cardiology, often requiring precise localization for optimal treatment. Its incidence is relatively low, affecting 3.7%–5.7% of children undergoing electrophysiological studies.1 While catheter ablation complements pharmacological therapy, achieving a high success rate of approximately 90%, there is room for enhancement.1 A challenge lies in mapping and ablating transient episodes of AT. Recent innovations in mapping technologies, notably charge density mapping, have shown promise in providing precise single-beat noncontact mapping of transient AT in adult patients.2,3 This mapping technique uses individualized anatomy of a heart chamber, created by ultrasound crystals that are integrated in a basket catheter, with subsequent visualization of recorded cardiac dipoles.4 This article explores a unique case with short runs of ectopic AT, demonstrating the efficacy of single-beat noncontact mapping using charge density mapping in a pediatric patient

Genetic parameters and genotype by environment interaction of Eucalyptus grandis populations used in intraspecific hybrid production in South Africa

In South Africa, Eucalyptus grandis is an important species due to its fast growth and general suitability of its timber for a range of products. However, E. grandis is susceptible to fungal diseases such as Crysoporthe austroafricana and Coniothyrium sp. cankers in the subtropical region of Zululand and is therefore mainly planted as a parental species in a hybrid combination with E. urophylla in this region. The current strategy is to maintain large breeding populations of both parental species in order to provide improved elite selections for hybrid crosses. In order to develop the best interspecific hybrid breeding strategy for E. grandis, it is important to first determine estimates of genetic parametersof the pure species parents. Estimating the genotype by environment interaction (G×E) is also necessary in proposing the basis for setting up breeding populations and selecting environmentally stable genotypes. With this in mind, two E. grandis full-sib progeny trials were planted in Zululand and one in the KwaZulu-Natal Midlands region. The aims of this study were firstly to determine the magnitude of G×E of E. grandis across the three sites; secondly, to estimate the genetic parameters for growth of the E. grandis parents selected for intraspecific crosses; and lastly, to identify the best parents to use for intra- and interspecific crosses in future hybrid breeding programmes. Results of our study indicated that G×E would be practically negligible for growth in Zululand and one group of elite parents can be used for hybrid crosses in this region. In general, growth traits were under low to moderate genetic control, and the variation in additive geneticsenabled us to identify E. grandis parents that could be utilised for intraspecific crosses and deliver progeny with genetic gains of 28.4%. Our study also highlighted that a relatively large portion of the genetic variation was explained by dominance geneticvariation and a strategy to capture this non-additive variation needs investigation. Although our study achieved the stated aims, it must be kept in mind that E. grandis is mainly used as a hybrid parent with E. urophylla in Zululand. A study to investigate whether the parents with good general combining ability values from our study are also good general combiners in interspecific hybrid combinations with E. urophylla needs to be conducted.Mondi training departmenthttp://www.tandfonline.com/loi/tsfs202017-11-28fb2017Forestry and Agricultural Biotechnology Institute (FABI)Microbiology and Plant Patholog

Estimates of genetic parameters and genetic gains for growth traits of two Eucalyptus urophylla populations in Zululand, South Africa

In South Africa, Eucalyptus urophylla is an important species due to its disease tolerance to fungal diseases like Crysoporthe austroafricana and the Coniothyrium sp. cankers. It is mainly planted as a parental species in a hybrid combination with E. grandis. Generally, the E. grandis x E. urophylla hybrid has better disease tolerance and higher wood density than pure E. grandis. The current strategy is to maintain large breeding populations of both parental species in order to provide improved elite selections for hybrid crosses on a regular basis. With this in mind, two E. urophylla populations, consisting of five provenance/progeny trials, were established in the subtropical region of Zululand. The aims of this study were firstly to determine the magnitude of genotype by environment interaction of E. urophylla in Zululand; secondly to estimate genetic parameter and correlations for DBH, height and volume; and lastly to identify selections to advance the current breeding population as well as to hybridise with E. grandis. Results indicated that genotype by environment interaction effects would be practically negligible for growth in Zululand and a single breeding population will therefore be appropriate. In general, all growth traits were under low to moderate genetic control, with narrow sense heritabilities ranging between 0.14 and 0.48 for volume. The genetic correlations between growth traits were high (0.98 and 0.99 for DBH-volume). This is an indication that DBH is a sufficient growth measure to use in E. urophylla breeding programmes. BLUP estimates indicated that a selection scenario of 200 individuals will generate genetic gains of 44.7% over the population mean. The estimated gains for the top 50 individuals that could potentially be used as hybrid parents to cross with E. grandis was 59.8% over the population mean.Funding was provided by Mondi training department.http://www.tandfonline.com/loi/tsfs202017-08-31hb2016Plant Production and Soil Scienc

Genetic parameters of interspecific hybrids of Eucalyptus grandis and E.urophylla seedings and cuttings

The current E. grandis x E. urophylla hybrid breeding strategy of South Africa’s Forestry Industry is to maintain large breeding populations of both parental species in which parents are selected based on their general combining ability (GCA) estimates or predicted individual tree breeding values and are used for interspecific hybrid crosses. The hybrid material is first screened in seedling progeny trials after which superior individuals are selected and tested as clones. Although this strategy has delivered superior clones for commercial production in South Africa, it is a time consuming strategy to follow and more cost effective strategies are being investigated. In order to review the current hybrid breeding strategy, information on the genetic control of the traits of interest is needed for E. grandis x E. urophylla seedling and clonal populations. The main objectives of this study were therefore to firstly estimate genetic parameters for E. grandis x E. urophylla hybrid seedling and clonal populations; secondly to investigate the correlation between E. grandis and E. urophylla parental (GCA) or individual breeding values and their general hybridising ability (GHA); and lastly to determine the correlation between E. grandis x E. urophylla hybrid seedling ortets and their ramets. Results of our study indicated that non-additive genetic variation explained the majority of the total genetic variation in E. grandis x E. urophylla seedling and clonal populations. Due to the pre-eminence of non-additive variance, the pure-hybrid correlations were weak, especially for clonal populations. It would therefore seem that GCA or predicted individual breeding values are not good predictors of GHA for growth performance in the observed populations. Our study also indicated a weak coefficient of correlation between the growth performance of seedling ortets and their ramets. These results suggest that: firstly a hybrid breeding strategy to capture non-additive genetic variation should be adopted; and secondly that the first phase of screening E. grandis x E. urophylla hybrid material as seedlings should be revisited. Genetic Parameters of Interspecific Hybrids of Eucalyptus grandis and E. urophylla Seedlings and Cuttings.Mondi training departmenthttp://www.sauerlaender-verlag.com/zeitschriften/silvae-geneticaPlant Production and Soil Scienc

MEASUREMENT OF THE SHORTEST PATH LENGTH; DISTANCE ESTIMATION WITHIN THE 3D BORDERS OF A TISSUE OF INTEREST

Volume data, such as 3D reconstructions from histological sections orMRI and CT data, are commonly used in studies in biology and medicine. The quantification of morphological parameters and changes within a region of interest is a key concern in such studies. Specifically, it is often required to measure the distance between two points. These distance measurements have to follow a track through the tissue when measuring in sheetlike or contorted organs like the developing heart. A tool was developed that enables this kind of distance measurements. Three existing neighborhood estimators were compared; two of Verwer and one of Kiryati, all originally designed to compute chamfer distances in data sets with isotropic, cubic voxels. The estimators were therefore adjusted to handle non-isotropic data sets. Moreover, the shortest path along a track within a given tissue was calculated. The measurement of known distances, through a simplified model of an early heart tube, with anisotropic voxels was used decide which of the three estimators should be implemented. The observed Root Mean Square (RMS) errors were similar to the ones reported in literature in the unrestrained isotropic case. The adjusted Verwer estimator measuring in a 53 neighborhood performed best by far with the lowest mean and RMS errors