WHY SOME YARROWIA LIPOLYTICA STRAINS SECRET CITRIC ACID TO THE MEDIUM?

2020 ◽  
Vol 23 (3) ◽  
Author(s):  
Małgorzata Robak ◽  
Keyword(s):  
Citric Acid ◽  
Metabolic Regulation ◽  
Transport Systems ◽  
Strain Development ◽  
Future Studies ◽  
Metabolism Regulation ◽  
Starting Point ◽  
Check Points ◽  
Intracellular Ca ◽  
Strain Dependent

Despite many studies, the “check points” of metabolic regulation of citric acid (CA) secretion by the yeasts Y.lipolytica still remain unknown. In this manuscript, some possible aspects of strain dependent secretion as well as CA metabolism regulation were discussed. Keys enzymes’ activities, substrate concentration, affinity of the uptake systems, intracellular CA concentration and strains abilities were the main points taken into consideration. The direction for the future studies emerged from this review, mainly connected to cellular and mitochondrial citrate transport systems and cellular substrates transporters (glucose, fructose, glycerol, ethanol and acetate), give promising starting point for future efficient strain development.

scholarly journals A publicly available repository of ROH islands reveals signatures of selection in different livestock and pet species

2021 ◽  
Vol 53 (1) ◽  
Author(s):  
Wim Gorssen ◽  
Roel Meyermans ◽  
Steven Janssens ◽  
Nadine Buys
Keyword(s):  
Association Studies ◽  
Genome Wide Association Studies ◽  
Single Nucleotide ◽  
Future Studies ◽  
Snp Data ◽  
Animal Populations ◽  
Genome Wide ◽  
Starting Point ◽  
Different Populations ◽  
Signatures Of Selection

Abstract Background Runs of homozygosity (ROH) have become the state-of-the-art method for analysis of inbreeding in animal populations. Moreover, ROH are suited to detect signatures of selection via ROH islands and are used in other applications, such as genomic prediction and genome-wide association studies (GWAS). Currently, a vast amount of single nucleotide polymorphism (SNP) data is available online, but most of these data have never been used for ROH analysis. Therefore, we performed a ROH analysis on large medium-density SNP datasets in eight animal species (cat, cattle, dog, goat, horse, pig, sheep and water buffalo; 442 different populations) and make these results publicly available. Results The results include an overview of ROH islands per population and a comparison of the incidence of these ROH islands among populations from the same species, which can assist researchers when studying other (livestock) populations or when looking for similar signatures of selection. We were able to confirm many known ROH islands, for example signatures of selection for the myostatin (MSTN) gene in sheep and horses. However, our results also included multiple other ROH islands, which are common to many populations and not identified to date (e.g. on chromosomes D4 and E2 in cats and on chromosome 6 in sheep). Conclusions We are confident that our repository of ROH islands is a valuable reference for future studies. The discovered ROH island regions represent a unique starting point for new studies or can be used as a reference for future studies. Furthermore, we encourage authors to add their population-specific ROH findings to our repository.

Effective Surveillance Management during Service Encounters

2017 ◽  
pp. 118-139
Author(s):  
Angelo Bonfanti
Keyword(s):  
Service Quality ◽  
Conceptual Framework ◽  
Customer Service ◽  
Service Management ◽  
Service Encounters ◽  
Surveillance Systems ◽  
Future Studies ◽  
Starting Point ◽  
Management Perspective ◽  
Service Oriented

This chapter aims to theoretically examine effective surveillance management (ESM) during service encounters within the servicescape and provide a conceptual framework for the study of this topic in a service management perspective. It analyses antecedents, dimensions and effects of ESM. This study especially proposes as antecedents both improving customer service experience along with meeting customers' need for security and implementing a surveillance service-oriented strategy that includes secure and safe servicescape design, deterrent communication, and trained and motivated security staff. This chapter suggests also that the dimensions of ESM (customer-physical service environment encounters, customer-technological surveillance systems encounters, and customer-security staff encounters) contribute to enhancing service quality, experience quality, and staff productivity. The integration of these dimensions, antecedents, and effects create a theoretically grounded framework that can serve as a starting point for future studies about this topic in the field of service management.

scholarly journals Metabolic regulation and glucose sensitivity of cortical radial glial cells

2018 ◽  
Vol 115 (40) ◽  
pp. 10142-10147 ◽  
Author(s):  
Brian G. Rash ◽  
Nicola Micali ◽  
Anita J. Huttner ◽  
Yury M. Morozov ◽  
Tamas L. Horvath ◽  
...  
Keyword(s):  
Glial Cells ◽  
Metabolic Regulation ◽  
Physiological Mechanism ◽  
Metabolic Disturbances ◽  
Mitochondrial Transport ◽  
Radial Glial Cells ◽  
Intracellular Ca ◽  
Glucose Sensitivity ◽  
Radial Glial ◽  
Primary Stem

The primary stem cells of the cerebral cortex are the radial glial cells (RGCs), and disturbances in their operation lead to myriad brain disorders in all mammals from mice to humans. Here, we found in mice that maternal gestational obesity and hyperglycemia can impair the maturation of RGC fibers and delay cortical neurogenesis. To investigate potential mechanisms, we used optogenetic live-imaging approaches in embryonic cortical slices. We found that Ca2+signaling regulates mitochondrial transport and is crucial for metabolic support in RGC fibers. Cyclic intracellular Ca2+discharge from localized RGC fiber segments detains passing mitochondria and ensures their proper distribution and enrichment at specific sites such as endfeet. Impairment of mitochondrial function caused an acute loss of Ca2+signaling, while hyperglycemia decreased Ca2+activity and impaired mitochondrial transport, leading to degradation of the RGC scaffold. Our findings uncover a physiological mechanism indicating pathways by which gestational metabolic disturbances can interfere with brain development.

A Proposal for a System of Classification for Anthroposophic Meditation

2019 ◽  
Vol 27 (2) ◽  
pp. 77-88
Author(s):  
Terje Sparby
Keyword(s):  
Classification System ◽  
Textual Analysis ◽  
Rudolf Steiner ◽  
Future Studies ◽  
Contemporary Science ◽  
Activity Sequence ◽  
Starting Point ◽  
Close Textual Analysis ◽  
External Conditions

Background: The investigation of the specific connections between different techniques of meditation and their respective effects depends upon a classification of the meditative activity involved. Universal systems of classification need to be developed based both on traditional sources and contemporary science. In this article, a system of classification for anthroposophical meditation is proposed. Methods: The system was developed from a close textual analysis of meditation instructions given by Rudolf Steiner. The system of classification arising from the investigation was compared to three other classificatory systems that have recently been suggested. Results: The analysis resulted in a system of classification with two main branches: (1) the shared features of anthroposophical meditation and (2) the different aspects of specific anthroposophical meditations. The first branch contains the following sub-categories: understanding, internal conditions, external conditions, sequence, timeframe and dealing with hindrances. The second branch contains: source, aim, activity, sequence and timeframe. Other systems of classification tend to leave out the dimension of the meditative activity. Conclusion: The proposed classification system can be used as a starting point for further refinements of the classification of anthroposophic meditation, but it can also be used as a standard for future studies of the connections between different meditations and their effects.

Entrepreneurial academics: a taxonomy with Latent Profile Analysis

2019 ◽  
Vol 57 (12) ◽  
pp. 3346-3363 ◽  
Author(s):  
Ricardo Gouveia Rodrigues ◽  
João J.M. Ferreira ◽  
Teresa Felgueira
Keyword(s):  
Higher Education ◽  
Latent Profile Analysis ◽  
Profile Analysis ◽  
Data Gathering ◽  
Content Type ◽  
Individual Entrepreneurial Orientation ◽  
Future Studies ◽  
Starting Point ◽  
E Mail ◽  
Latent Profile

Purpose The need for dynamic and innovative skills and the importance of resources and individuals in pursuit of new opportunities prove to be extremely vital for the higher education institutions (HEI). The purpose of this paper is to develop a taxonomy of academics from HEI, based on their individual entrepreneurial orientation (EO). Design/methodology/approach The population in study was composed of teachers and researchers from worldwide HEI. The data collection was conducted through a questionnaire sent by an e-mail and the authors used the I-ENTRE-U scale to identify entrepreneurial-oriented teachers and researchers from HEI. A Latent Profile Analysis (LPA) was conducted to identify profiles of researchers with similar values in four EO dimensions. Findings The study allowed the authors to identify five profiles of researchers: downers, achievers, followers, defenders and rebels. Research limitations/implications The results can be an important starting point for other researchers and practitioners hoping to evaluate academics’ EO in a higher education sector. The taxonomy also allows wider predictions about the behaviour of the profile members of profiles and relates it with other variables such as performance. Further contributions may be added by extending the data gathering from different geographical areas and/or different academic contexts, such that future studies could apply other LPA techniques and compare the results. Originality/value Only few studies have focussed on individual EO of scientists/academics, considering different national and regional contexts. To the best of the authors’ knowledge, this is the first empirical study that develops a taxonomy of academics from HEI, based on their individual EO.

On the nomological net of (non-)workaholic subtypes

2019 ◽  
Vol 24 (7) ◽  
pp. 672-685
Author(s):  
Greta Ontrup ◽  
Justine Patrzek
Keyword(s):  
Latent Profile Analysis ◽  
Profile Analysis ◽  
Statistical Technique ◽  
Online Questionnaire ◽  
Cross Sectional ◽  
Content Type ◽  
Future Studies ◽  
Model Based Clustering ◽  
Starting Point ◽  
Cross Sectional Design

Purpose Research on workaholism distinguishes between enthusiastic and non-enthusiastic workaholics, a typology used in many studies. Yet, the methodical foundation on which the derivation of the types is based lacks robust statistical evidence. The purpose of this paper is twofold: first, to replicate the often-cited typology of enthusiastic and non-enthusiastic workaholics (and non-workaholic subtypes), based on model-based clustering as a robust statistical technique; and second, to validate the class solution based on affective, cognitive and behavioral measures. Design/methodology/approach The study followed a cross-sectional design, targeting a sample of people from various fields of industries. An online questionnaire was distributed; workaholism was assessed with McMillan et al.’s (2002) Work-BAT-R scales. A total of 537 respondents’ data were analyzed. Findings Latent profile analysis extracted four classes, namely, enthusiastic and non-enthusiastic workaholics and relaxed and uninvolved non-workaholics. As expected, workers characterized by high enjoyment (enthusiasts and relaxed) showed higher job satisfaction and occupational self-efficacy than workers with low enjoyment (non-enthusiasts and uninvolved). Relaxed workers reported higher life satisfaction than all other classes. Originality/value The robust methodology applied establishes a good starting point for future studies investigating workers subtypes: the replication suggests that the workaholic subtypes might be core profiles that occur in different populations with regularity. As a next step, the replication of the typology based on alternative operationalizations of workaholism is proposed for future studies.

scholarly journals Different Densities of Na-Ca Exchange Current in T-Tubular and Surface Membranes and Their Impact on Cellular Activity in a Model of Rat Ventricular Cardiomyocyte

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
M. Pásek ◽  
J. Šimurda ◽  
G. Christé
Keyword(s):  
Action Potential ◽  
Transport Systems ◽  
Duration Of Action ◽  
Rat Cardiomyocytes ◽  
Adult Rat ◽  
Before And After ◽  
Action Potential Waveform ◽  
Intracellular Ca ◽  
Tubular Membranes ◽  
Potential Waveform

The ratio of densities of Na-Ca exchanger current (INaCa) in the t-tubular and surface membranes (INaCa-ratio) computed from the values ofINaCaand membrane capacitances (Cm) measured in adult rat ventricular cardiomyocytes before and after detubulation ranges between 1.7 and 25 (potentially even 40). Variations of action potential waveform and of calcium turnover within this span of theINaCa-ratio were simulated employing previously developed model of rat ventricular cell incorporating separate description of ion transport systems in the t-tubular and surface membranes. The increase ofINaCa-ratio from 1.7 to 25 caused a prolongation of APD (duration of action potential at 90% repolarisation) by 12, 9, and 6% and an increase of peak intracellular Ca2+transient by 45, 19, and 6% at 0.1, 1, and 5 Hz, respectively. The prolonged APD resulted from the increase ofINaCadue to the exposure of a larger fraction of Na-Ca exchangers to higher Ca2+transients under the t-tubular membrane. The accompanying rise of Ca2+transient was a consequence of a higher Ca2+load in sarcoplasmic reticulum induced by the increased Ca2+cycling between the surface and t-tubular membranes. However, the reason for large differences in theINaCa-ratio assessed from measurements in adult rat cardiomyocytes remains to be explained.

Migration in West Africa: a savanna village prespective

Africa ◽  
1991 ◽  
Vol 61 (2) ◽  
pp. 222-246 ◽  
Author(s):  
David A. Cleveland
Keyword(s):  
Labour Productivity ◽  
Arable Land ◽  
Good News ◽  
Population Pressure ◽  
Transport Systems ◽  
Land Productivity ◽  
Long Distance ◽  
Starting Point ◽  
Working Age ◽  
Southern Ghana

AbstractLocal migration in response to population pressure is part of the history of northeast Ghana. First by physical coercion, then by economic coercion, colonialism drastically changed the pattern of migration to one of long-distance movement from north-east Ghana and the northern savannas in general to southern Ghana. Migration in turn affected social organisation, agriculture and population dynamics n i savanna communities. While colonial policy was not always consistent, one dominant and ultimately effective strategy seems evident: to break up locally self-sufficient economies and societies in order to stimulate the temporary migration of labour from largely subsistence agriculture to work in commercial agriculture, mining and public works in the south. These sectors were directly tied to the European economy for the benefit of Britain. Low wages and poor working conditions encouraged most migrants to return to their savanna villages when they were sick, injured or too old to work.When Ghana gained its political independence from Britain this new pattern of migration had become firmly established and was maintained by changes in the social, economic and transport systems. Data from Zorse and the Upper Region show that migration at any one time takes about 50 per cent of working-age males and 15 per cent of working-age females to southern Ghana for periods of a year or more. Significantly increased dependency ratios mean that as a result of this migration each four remaining working-age adults must support themselves plus four dependants, instead of supporting only three dependants, as would be the case without migration. Since remittances by Zorse migrants are equal to only a small fraction of the value of their lost productive labour, the net effect of migration on the food consumption level of those remaining in the village will be determined by the balance between the increased output required of each remaining working-age adult and the decreased yield required of the total area of arable land. While I do not have all the quantitative data needed to resolve this question, statements by Zorse residents, evidence of chronic undernutrition, a long-term decrease in land productivity due to erosion and lack of organic matter, and serious labour shortages during periods of critical farm activity, suggest that the net effect of migration on Zorse is negative. That is, neither labour productivity nor land productivity is likely to compensate for the higher dependency ratio.While it may be true that migrants vote with their feet, the choice of paths is often determined by forces in the larger system beyond their control. The good news is that indigenous agricultural and demographic knowledge and practices in Africa may provide the starting point for a sustainable future if the patterns established by colonialism and reinforced by ‘modern’ economic development can be changed.

A Critical Review on Condensation Heat Transfer in Microchannels and Minichannels

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
M. M. Awad ◽  
A. S. Dalkiliç ◽  
S. Wongwises
Keyword(s):  
Heat Transfer ◽  
Critical Review ◽  
Saturation Temperature ◽  
Thermal Control ◽  
Condensation Heat Transfer ◽  
Technical Equipment ◽  
Channel Diameter ◽  
Future Studies ◽  
Starting Point ◽  
Wide Range

Condensation in microchannels and minichannels is widely used in small devices such as air-cooled condensers for the air-conditioning and automotive industry, in heat pipes, thermosyphons and other applications for system thermal control. Currently, many research centers all over the world are dealing with the structure and operation of compact refrigerating devices. This is in line with the trend of 21st century that is moving towards the use of energy-saving and environmentally friendly technical equipment. In the present study, a critical review on condensation heat transfer in microchannels and minichannels is presented. This review include a wide range of different parameters such as the channel diameter (d), the saturation temperature (Ts), the mass flux (G), the vapor quality (x), different working fluids like steam, CO2 or R744, FC72, R22, R410A, and R407C, various shapes such as circular and noncircular, different orientations like horizontal and vertical, and systems consist of either single or multiple channels. At the end, recommendations for future studies will be given. As a result, this paper cannot only be used as the starting point for the researcher interested in condensation heat transfer in microchannels and minichannels, but it also includes recommendations for future studies on condensation heat transfer in microchannels and minichannels.

Sign in / Sign up

Export Citation Format

Share Document