Induced voltage in an open wire

A puzzle arising from Faraday's law is considered and solved concerning the question which voltage is induced in an open wire with a time-varying homogeneous magnetic field. In contrast to closed wires where the voltage is determined by the time variance of magnetic field and enclosed area, in an open wire we have to integrate the electric field along the wire. It is found that the longitudinal electric field contributes with 1/3 and the transverse field with 2/3 to the induced voltage. In order to find the electric fields the sources of the magnetic fields are necessary to know. The representation of a homogeneous and time-varying magnetic field implies unavoidably a certain symmetry point or symmetry line which depend on the geometry of the source. As a consequence the induced voltage of an open wire is found to be the area covered with respect to this symmetry line or point perpendicular to the magnetic field. This in turn allows to find the symmetry points of a magnetic field source by measuring the voltage of an open wire placed with different angles in the magnetic field. We present exactly solvable models for a symmetry point and for a symmetry line, respectively. The results are applicable to open circuit problems like corrosion and for astrophysical applications

Image Analysis of Morphological Changes in Wiener Batters During Chopping and Cooking

Histological changes in wiener batters during chopping and cooking have often been illustrated with representative fields . The practice of selecting representative fields ignores variation and leads to word descriptions that cannot be correlated with numerical scores for functional or sensory tests . If wieners are regarded as a multi-component system, objectivity can be achieved by selecting many fields for each sample according to a rigid sampling plan. Image analysis quantified parameters of both the fat and protein components . The reduction in size of fat globules during chopping of a commercial formulation, for example, was a function of area and aggregate perimeter of several hundred globules compiled by a computer . There was no relationship between wiener firmness and any feature of the microstructure ; but even at a low magnification of 30x , several statistically different factors were exposed during this survey which require further study

Host perspectives on ethnic minority tourism in Northern Thailand

In recent years tourism scholarship has increasingly recognized the role and importance of host perspectives in ethnic minority tourism. The main aim of this paper is to explicate the opinions and perceptions of ethnic minority communities in Northern Thailand. By drawing on emerging concepts of the host gaze I aim to further the understanding of how local residents in the field of ethnic tourism perceive and gaze upon the various actors and dimensions of ethnic tourism. Based on a qualitative research study employing semi-structured interviews and participant observation in two minority villages with different touristic intensity, this paper uncovers local perspectives on and gazes upon different types of tourists, tour guides and tensions in ethnic tourism such as modernization versus exoticism or the question of tourism and cultural revitalization

New religious travel segment

The focus of this study is on the emergence of a new religious travel segment: Umrah Do It Yourself (DIY) travelers. The Umrah journey is organised by a specially licenced travel agent who handles all of the necessary arrangements, including flights and trip itineraries. However, a small percentage of travellers choose not to use such agencies and instead make their own arrangements, and the Saudi Arabian government's intention to launch a Tourist e-Visa in September 2019 has provided a window of opportunity to legalise Umrah DIY excursions. The study's objectives are to investigate how travel motivations contribute to the success of Umrah DIY. A hermeneutic phenomenological technique was employed to address the research gap. Participants were recruited via an Umrah DIY Facebook group, where 20 people volunteered and signed consent forms to help with the research process. According to the findings, the most crucial reason to engage on this quest is flexibility. This study aims to fill the gap of "religion" as a travel element, which is seen as an opportunity for suppliers and industry participants to address this segment by gaining a better understanding of their travel motivations as the foundation for developing relevant religious tourism products and services. Religious and spiritual journeys in Islam are classified into three types: Hajj, Umrah, and Ziyara (Hassan et al., 2015; Timothy & Olsen, 2006). While Umrah is part of the journey to Mecca, Muslims are only required to perform the first Umrah. According to Hassan et al. (2015), Umrah can be performed more than once, and it can be repeated dependent on the individual's physical and financial abilities. Hajj and Umrah travel have been mostly organised in a closely controlled manner in - packaged group tours (Haq & Jackson, 2009). According to Hassan et al. (2016), Umrah package travellers are those who buy products (Umrah package travel) from local tour operators and travel agents for religious and spiritual reasons, combining lodging, transportation, itinerary, and meals. The Kingdom of Saudi Arabia issued over four million Umrah visas in 2013 to travellers from 70 countries, and the number of visitors increased year after year until the outbreak of COVID-19 (Muneeza & Mustapha, 2021). Recent trends in Umrah individualism and Do-it-yourself (DIY) travel can be seen (Almuhrzi & Alsawafi, 2017). This is also demonstrated by the Umrah DIY Facebook forum, which has 10,000 members, and current articles about Umrah DIY conducted in Indonesia (Lailatul & Melinda, 2018; Ubaidillah, 2021). Despite the fact that significant proof has already been provided on Umrah travellers' journeys, there is a lack of explanation on Umrah DIY travellers. The only study on Umrah DIY found focused on the feasibility of Umrah backpackers among young Indonesian travellers (Lailatul & Melinda, 2018; Fakhruddin & Ubaidillah, 2021), and Hajj backpackers on the possibilities and obstacles of religious travellers (Kusumaningtyas, 2019). With the Saudi Arabian government's reform of the E-Umrah Visa policy in 2019, there is an increasing trend of international pilgrims travelling to the holy sites to perform their Umrah on their own rather than through travel agencies. Flexibility, information sources, familiarity, travel quality, companion, budget travel, and spirituality are emerging themes that explain why Umrah DIYers choose to organise and handle their most significant lifetime journey on their own. Furthermore, as travellers seek ways to maximise their experiences, this research could aid in the development of DIY Umrah travel choices

Deep Mining of Oxysterols and Cholestenoic Acids in Human Plasma and Cerebrospinal Fluid: Quantification using Isotope Dilution Mass Spectrometry

Both plasma and cerebrospinal fluid (CSF) are rich in cholesterol and its metabolites. Here we describe in detail a methodology for the identification and quantification of multiple sterols including oxysterols and sterol-acids found in these fluids. The method is translatable to any laboratory with access to liquid chromatography – tandem mass spectrometry. The method exploits isotope-dilution mass spectrometry for absolute quantification of target metabolites. The method is applicable for semi-quantification of other sterols for which isotope labelled surrogates are not available and approximate quantification of partially identified sterols. Values are reported for non-esterified sterols in the absence of saponification and total sterols following saponification. In this way absolute quantification data is reported for 17 sterols in the NIST SRM 1950 plasma along with semi-quantitative data for 8 additional sterols and approximate quantification for one further sterol. In a pooled (CSF) sample used for internal quality control, absolute quantification was performed on 10 sterols, semi-quantification on 9 sterols and approximate quantification on a further three partially identified sterols. The value of the method is illustrated by confirming the sterol phenotype of a patient suffering from ACOX2 deficiency, a rare disorder of bile acid biosynthesis, and in a plasma sample from a patient suffering from cerebrotendinous xanthomatosis, where cholesterol 27-hydroxylase is deficient

The emergence of a new religious travel segment: Umrah do it yourself travellers (DIY)

This research examines the rise of a new religious travel segment – the Umrah Do It Yourself (DIY) travellers. While Hajj is the fifth pillar of Islam, Umrah is a minor Muslim pilgrimage that can be undertaken at any time of the year, while still playing a crucial role in the completion of Hajj rituals. In the past, Umrah was managed by an authorised travel agent, who makes all the necessary pilgrimage preparations, from flights to trip itineraries. Recent years have seen an upsurge in travellers who prefer not to utilise the services of such agencies, but instead, to make their own arrangements. The decision by the Saudi Arabian government to launch a Tourist e-Visa in September 2019 has opened a window of opportunity for the legalization of Umrah DIY journeys. The objectives of this study are (i) to explore the travel motives that contribute to the success of the Umrah DIY, and (ii) to explore the factors that support and facilitate the decision for the Umrah DIY. The data were obtained via 20 semi-structured interviews with Umrah DIY travellers. The findings show that flexibility, spirituality, and budget have a crucial impact on travel motivation. Additionally, the findings suggest that information sources, travel quality, companionship/new friendship, and familiarity facilitate the choice of Umrah DIY travel. This research contributes to the growing scholarship on the Muslim travel market beyond Hajj and to studies on independent religious travel. Findings provide an opportunity for suppliers and industry participants to understand the travel motives of this new segment as a basis for producing relevant religious tourism products and services

GDNF Selectively Induces Microglial Activation and Neuronal Survival in CA1/CA3 Hippocampal Regions Exposed to NMDA Insult through Ret/ERK Signalling

The glial cell line-derived neurotrophic factor (GDNF) is a potent survival factor for several neuronal populations in different brain regions, including the hippocampus. However, no information is available on the: (1) hippocampal subregions involved in the GDNF-neuroprotective actions upon excitotoxicity, (2) identity of GDNF-responsive hippocampal cells, (3) transduction pathways involved in the GDNF-mediated neuroprotection in the hippocampus. We addressed these questions in organotypic hippocampal slices exposed to GDNF in presence of N-methyl-D-aspartate (NMDA) by immunoblotting, immunohistochemistry, and confocal analysis. In hippocampal slices GDNF acts through the activation of the tyrosine kinase receptor, Ret, without involving the NCAM-mediated pathway. Both Ret and ERK phosphorylation mainly occurred in the CA3 region where the two activated proteins co-localized. GDNF protected in a greater extent CA3 rather than CA1 following NMDA exposure. This neuroprotective effect targeted preferentially neurons, as assessed by NeuN staining. GDNF neuroprotection was associated with a significant increase of Ret phosphorylation in both CA3 and CA1. Interestingly, confocal images revealed that upon NMDA exposure, Ret activation occurred in microglial cells in the CA3 and CA1 following GDNF exposure. Collectively, this study shows that CA3 and CA1 hippocampal regions are highly responsive to GDNF-induced Ret activation and neuroprotection, and suggest that, upon excitotoxicity, such neuroprotection involves a GDNF modulation of microglial cell activity

Changes in Glial Cell Line-derived Neurotrophic Factor Expression in the Rostral and Caudal Stumps of the Transected Adult Rat Spinal Cord

Limited information is available regarding the role of endogenous Glial cell line-derived neurotrophic factor (GDNF) in the spinal cord following transection injury. The present study investigated the possible role of GDNF in injured spinal cords following transection injury (T9–T10) in adult rats. The locomotor function recovery of animals by the BBB (Basso, Beattie, Bresnahan) scale score showed that hindlimb support and stepping function increased gradually from 7 days post operation (dpo) to 21 dpo. However, the locomotion function in the hindlimbs decreased effectively in GDNF-antibody treated rats. GDNF immunoreactivty in neurons in the ventral horn of the rostral stump was stained strongly at 3 and 7 dpo, and in the caudal stump at 14 dpo, while immunostaining in astrocytes was also seen at all time-points after transection injury. Western blot showed that the level of GDNF protein underwent a rapid decrease at 7 dpo in both stumps, and was followed by a partial recovery at a later time-point, when compared with the sham-operated group. GDNF mRNA-positive signals were detected in neurons of the ventral horn, especially in lamina IX. No regenerative fibers from corticospinal tract can be seen in the caudal segment near the injury site using BDA tracing technique. No somatosensory evoked potentials (SEP) could be recorded throughout the experimental period as well. These findings suggested that intrinsic GDNF in the spinal cord could play an essential role in neuroplasticity. The mechanism may be that GDNF is involved in the regulation of local circuitry in transected spinal cords of adult rats

Mutation and deletion analysis of GFRα-1, encoding the co-receptor for the GDNF/RET complex, in human brain tumours

Glial cell line-derived neurotrophic factor (GDNF) plays a key role in the control of vertebrate neuron survival and differentiation in both the central and peripheral nervous systems. GDNF preferentially binds to GFRα-1 which then interacts with the receptor tyrosine kinase RET. We investigated a panel of 36 independent cases of mainly advanced sporadic brain tumours for the presence of mutations in GDNF and GFRα-1. No mutations were found in the coding region of GDNF. We identified six previously described GFRα-1 polymorphisms, two of which lead to an amino acid change. In 15 of 36 brain tumours, all polymorphic variants appeared to be homozygous. Of these 15 tumours, one also had a rare, apparently homozygous, sequence variant at codon 361. Because of the rarity of the combination of homozygous sequence variants, analysis for hemizygous deletion was pursued in the 15 samples and loss of heterozygosity was found in 11 tumours. Our data suggest that intragenic point mutations of GDNF or GFRα-1 are not a common aetiologic event in brain tumours. However, either deletion of GFRα-1 and/or nearby genes may contribute to the pathogenesis of these tumours