The Glycolytic Pathway is the Predominate Path for Glucose Utilization in Human Pancreatic Beta Cells (1.1B4)

The oxidative metabolism of energy substrates has a paramount role in the stimulus secretion pathway of insulin. However, the role of glycolytic pathway in pancreatic beta cells is not very well understood. To address this, we have investigated and compared the functional effects of two mitochondrial substrates (glucose and α-ketoisocaproate) between the human (1.1B4) and murine (MIN6) pancreatic beta cell lines. MTS assay was conducted as an indicator of the metabolic activity of both cell lines. Polarographic detection of (ΔO2) and lactate were used to measure the oxygen consumption rate and anaerobic glycolysis respectively. The mitochondrial redox state was monitored via RH123 distribution and NAD(P)H autofluorescence. The metabolic assays showed glucose stimulated MTS reduction in MIN6 cells in a time and concentration dependent manner and nor in 1.1B4. Both sub strates failed to affect OCR, NADPH and increased lactate production in 1.1B4 cells. However, they stimulated OCR, increased NADPH, increased lactate output but was less extent and hyperpolarized the mitochondria in MIN6 cells. The above results showed that 1.1B4 cells are mainly depending on the glycolytic pathway different from MIN6 cells which rely on mitochondrial respiration. In conclusion, 1.1B4 cell line represents a new model to study the bioenergetics profile because it depends on the anaerobic glycolysis rather than aerobic respiration of the other models such as MIN6 and islets

Overexpression and characterization of dimeric and tetrameric forms of recombinant serine hydroxymethyltransferase from Bacillus stearothermophilus

Serine hydroxymethyltransferase (SHMT), a pyridoxal-5′-phosphate (PLP) dependent enzyme catalyzes the interconversion of L-Ser and Gly using tetrahydrofolate as a substrate. The gene encoding for SHMT was amplified by PCR from genomic DNA of Bacillus stearothermophilus and the PCR product was cloned and overexpressed in Escherichia coli. The purified recombinant enzyme was isolated as a mixture of dimer (90%) and tetramer (10%). This is the first report demonstrating the existence of SHMT as a dimer and tetramer in the same organism. The specific activities at 37°C of the dimeric and tetrameric forms were 6.7 U/mg and 4.1 U/mg, respectively. The purified dimer was extremely thermostable with a Tm of 85°C in the presence of PLP and L-Ser. The temperature optimum of the dimer was 80°C with a specific activity of 32×4 U/mg at this temperature. The enzyme catalyzed tetrahydrofolate-independent reactions at a slower rate compared to the tetrahydrofolate-dependent retro-aldol cleavage of L-Ser. The interaction with substrates and their analogues indicated that the orientation of PLP ring of B. stearothermophilus SHMT was probably different from sheep liver cytosolic recombinant SHMT (scSHMT)

Analisis Pengaturan Posisi Tap on Load Tap Changer Pada Transformator Daya 30 Mva 70/20 Kv Di Gi Maulafa

Gardu Induk Maulafa merupakan sub sitstem dalam sistem penyaluran daya listrik yang ada di Kota Kupang, memiliki dua buah transformator masing-masing 30 MVA 70/20 kV yang dilengkapi dengan OLTC. Pemasangan OLTC yang bertujuan untuk mendapatkan nilai tegangan sekunder yang stabil meskipun terjadi drop tegangan pada sisi primer, hal ini dikarenakan tap changer bekerja dengan cara merubah perbandingan lilitan dalam sebuah transformator. Hasil perhitungan dan analisis yang dilakukan pada OLTC transformator 1, posisi tap  berada  pada posisi 9, dengan jangkauan tegangan 20,94 kV pada saat beban puncak, dengan tegangan primer sebesar 69,12 kV. Untuk beban terendah, berada pada posisi 9 dengan jangkauan tegangan sebesar  20,85 kV dengan tegangan primer sebesar 68,81 kV.  Sedangkan untuk transformator 2 tegangan primernya  sebesar 69,08 kV untuk beban puncak dan 68,91 kV untuk beban terendah, berada  pada posisi 2 untuk beban puncak  dan posisi 1 untuk beban terendah, dengan Jangkauan tegangan masing-masing  21,19 kV dan 20,88 kV.     Posisi tap OLTC transformator 1 masih bisa diturukan ke posisi 6 dengan jangkauan tegangan sebesar 20,21 kV untuk beban puncak dan 20,11 kV untuk beban terendah. Kedua transformator memiliki pembebanan yang sama, baik beban puncak maupun beban terendah yakni 26 MW untuk beban puncak dan 15 MW untuk beban terendah.  &nbsp

Crystal structure of binary and ternary complexes of serine hydroxymethyltransferase from Bacillus stearothermophilus

Serine hydroxymethyltransferase (SHMT), a member of the α-class of pyridoxal phosphate-dependent enzymes, catalyzes the reversible conversion of serine to glycine and tetrahydrofolate to 5,10-methylene tetrahydrofolate. We present here the crystal structures of the native enzyme and its complexes with serine, glycine, glycine, and 5-formyl tetrahydrofolate (FTHF) from Bacillus stearothermophilus. The first structure of the serine-bound form of SHMT allows identification of residues involved in serine binding and catalysis. The SHMT-serine complex does not show any significant conformational change compared with the native enzyme, contrary to that expected for a conversion from an "open" to "closed" form of the enzyme. However, the ternary complex with FTHF and glycine shows the reported conformational changes. In contrast to the Escherichia coli enzyme, this complex shows asymmetric binding of the FTHF to the two monomers within the dimer in a way similar to the murine SHMT. Comparison of the ternary complex with the native enzyme reveals the structural basis for the conformational change and asymmetric binding of FTHF. The four structures presented here correspond to the various reaction intermediates of the catalytic pathway and provide evidence for a direct displacement mechanism for the hydroxymethyl transfer rather than a retroaldol cleavage

Vulnerability pathways to mental health outcomes in children and parents during COVID-19

We examined pathways from pre-existing psychosocial and economic vulnerability to mental health difficulties and stress in families during the COVID-19 pandemic. Data from two time points from a multi-cohort study initiated during the COVID-19 pandemic were used. Parents of children 6–18 years completed questionnaires on pre-COVID-19 socioeconomic and demographic factors in addition to material deprivation and stress due to COVID-19 restrictions, mental health, and family functioning. Youth 10 years and older also completed their own measures of mental health and stress. Using structural equation modelling, pathways from pre-existing vulnerability to material deprivation and stress due to COVID-19 restrictions, mental health, and family functioning, including reciprocal pathways, were estimated. Pre-existing psychosocial and economic vulnerability predicted higher material deprivation due to COVID-19 restrictions which in turn was associated with parent and child stress due to restrictions and mental health difficulties. The reciprocal effects between increased child and parent stress and greater mental health difficulties at Time 1 and 2 were significant. Reciprocal effects between parent and child mental health were also significant. Finally, family functioning at Time 2 was negatively impacted by child and parent mental health and stress due to COVID-19 restrictions at Time 1. Psychosocial and economic vulnerability is a risk factor for material deprivation during COVID-19, increasing the risk of mental health difficulties and stress, and their reciprocal effects over time within families. Implications for prevention policy and parent and child mental health services are discussed

ANALISIS PENGATURAN POSISI TAP ON LOAD TAP CHANGER PADA TRANSFORMATOR DAYA 30 MVA 70/20 KV DI GI MAULAFA

ABSTRACT The Maulafa substation is a sub-system in the electrical power distribution system in the city of Kupang, has two transformers of 30 MVA 70/20 kV each equipped with OLTC. OLTC installation aims to obtain a stable secondary voltage value despite the voltage drop on the primary side, this is because the tap changer works by changing the coil ratio in a transformer. The results of calculations and analyzes performed on transformer 1 OLTC, tap position  is in position 9, with a voltage range of 20.94 kV at peak load, with a primary voltage of 69.12 kV. For the lowest load, it is in position 9 with a voltage range of 20.85 kV with a primary voltage of 68.81 kV. Whereas for transformer 2 the primary voltage is 69.08 kV for peak load and 68.91 kV for lowest load, being in position 2 for peak load and position 1 for lowest load, with a range of voltage of 21.19 kV and 20 respectively. 88 kV. The OLTC tap position of transformer 1 can still be reduced to position 6 with a voltage range of 20.21 kV for peak loads and 20.11 kV for the lowest loads. Both transformers have the same loading, both peak load and lowest load of 26 MW for peak load and 15 MW for lowest load.    ABSTRAK Gardu Induk Maulafa merupakan sub sitstem dalam sistem penyaluran daya listrik yang ada di Kota Kupang, memiliki dua buah transformator masing-masing 30 MVA 70/20 kV yang dilengkapi dengan OLTC. Pemasangan OLTC yang bertujuan untuk mendapatkan nilai tegangan sekunder yang stabil meskipun terjadi drop tegangan pada sisi primer, hal ini dikarenakan tap changer bekerja dengan cara merubah perbandingan lilitan dalam sebuah transformator. Hasil perhitungan dan analisis yang dilakukan pada OLTC transformator 1, posisi tap  berada  pada posisi 9, dengan jangkauan tegangan 20,94 kV pada saat beban puncak, dengan tegangan primer sebesar 69,12 kV. Untuk beban terendah, berada pada posisi 9 dengan jangkauan tegangan sebesar  20,85 kV dengan tegangan primer sebesar 68,81 kV.  Sedangkan untuk transformator 2 tegangan primernya  sebesar 69,08 kV untuk beban puncak dan 68,91 kV untuk beban terendah, berada  pada posisi 2 untuk beban puncak  dan posisi 1 untuk beban terendah, dengan Jangkauan tegangan masing-masing  21,19 kV dan 20,88 kV.     Posisi tap OLTC transformator 1 masih bisa diturukan ke posisi 6 dengan jangkauan tegangan sebesar 20,21 kV untuk beban puncak dan 20,11 kV untuk beban terendah. Kedua transformator memiliki pembebanan yang sama, baik beban puncak maupun beban terendah yakni 26 MW untuk beban puncak dan 15 MW untuk beban terendah.  &nbsp

Landscape approaches for ecosystem management in Mediterranean Islands

This book presents a series of essays, drawing on the twm concepts of ecosystem management and landscape approaches, to elucidate and reflect on the present situation and future evolution of Mediterranean islands. This publication brings together contributions from Mediterranean individuals, non-Mediterranean individuals, islanders and non-islanders there is, after all, no geographical limit on who and what we can learn from. The essays presented here each contribute a specific perspective on the future evolution of Mediterranean islands. This book presents a series of essays, drawing on the twin concepts of ecosystem management and landscape approaches, to elucidate and reflect on the present situation and future evolution of Mediterranean islands. This publication brings together contributions from Mediterranean individuals, non-Mediterranean individuals, islanders and non-islanders; there is, after all, no geographical limit on who and what we can learn from. The essays presented here each contribute a specific perspective on the future evolution of Mediterranean islands. Following this introductory chapter, the first section of the book focuses on the contributions that can be made by the discipline of landscape ecology. loannis Vogiatzakis and Geoffrey Griffiths first explain the concepts and relevance of landscape ecology, also presenting and discussing a range of applied tools that can facilitate landscape planning in Mediterranean islands. Louis F. Cassar then reviews the 'offshoot' discipline of restoration ecology, making a strong case for offsetting the environmental damage inflicted on natural ecosystems over millennia of human occupation, with constructive efforts to effectively restore and/or rehabilitate ecosystems. The two following chapters bring the socio-economic dimension into the discussion. Godfrey Baldacchino first presents two contrasting paradigms for the development of island territories, reviewing the dual influences of ecological and economic factors, and exploring ways in which the two can be brought together in successful development strategies. Gordon Cordina and Nadia Farrugia then address the demographic dimension of development, presenting a model to explain the economic costs of high population densities on islands. The third block of chapters expands on the relevance of social and cultural dynamics to the management of Mediterranean Islands. Isil Cakcï, Nur Belkayali and Ilkden Tazebay explain the evolution of the concept of a 'cultural landscape', focusing on the challenges of managing change in landscapes with strong heritage values. The chapter concludes with a case study on the Turkish island of Gökçeada (lmbros), which is experiencing major challenges in balancing the conservation of a cultural landscape on the one hand, and the management of inevitable change, on the other. Elisabeth Conrad then discusses the role of social capital in managing the landscape resources of Mediterranean islands, reviewing the potential for this intangible social fabric to facilitate or impede the sustainable evolution of island territories. The fourth section includes four chapters, each of which addresses a different aspect relevant to policy development and implementation in Mediterranean islands. Salvino Busuttil presents an essay outlining the political influences on the management of coastal landscapes, the latter so relevant to Mediterranean island territories. The essay derives from the author's professional experience in various policy-related institutions for environmental management within the Mediterranean region. Maggie Roe then reflects on issues of landscape sustainability, focusing on the neglected aspect of intelligence. She discusses ways in which landscape research, knowledge and understanding can feed directly into frameworks for 'sustainable' landscape planning. In the subsequent chapter, Adrian Phillips takes from his substantial experience with international landscape policy, reviewing the gradual emergence of international and national landscape 'tools', to draw out lessons for application in Mediterranean islands. In the final chapter of this section, Riccardo Priore and Damiano Galla present a comprehensive discussion of the European Landscape Convention, the first international instrument to focus exclusively on landscape. The authors explain the innovative character of this convention, and discuss its potential implementation in Mediterranean islands. The publication concludes with a series of case studies, highlighting specific constraints, experiences and opportunities in different Mediterranean islands. Theano Terkenli explores the landscapes of tourism in Mediterranean islands - perhaps no other industry has played such a fundamental role in shaping the evolution of Mediterranean landscapes in recent years. The author reviews the theoretical relationship between landscape and tourism across Mediterranean islands, before focusing on the specific case of the Greek Cycladic islands. In the following chapter, Alex Camilleri, Isabella Colombini and Lorenzo Chelazzi present an in-depth review of the context and challenges being faced on a number of minor Mediterranean islands, namely those of the Tuscan archipelago (Elba, Giglio, Capraia, Montecristo, Pianosa, Gorgona and Giannutri), and Comino, the latter forming part of the Maltese archipelago. The comparison between these various islands enables an appreciation of both commonalities across these islands, as well as considerations that are specific to the context of each in dividual island. JeremyBoissevain then adopts an anthropological lens to review the cautionary tale of landscape change in Malta, exploring underlying causes of landscape destruction and limited civil engagement. In the subsequent chapter, Jala Makhzoumi outlines the richness of Mediterranean islands' rural landscapes, focusing on olive landscapes in Cyprus. Her research demonstrates the economic and ecological robustness of various olive cultivation practices, and whilst warning of several threats to such sustainable regimes, she outlines strategies for reconfiguring our approach to rural heritage, in order to integrate such assets into sustainable development strategies. Finally, Stephen Morse concludes the section with an evaluation of sustainable development indicators, and the contribution that these can make towards enhancing the management of Mediterranean island territories. He illustrates his arguments with reference to the two island states of Malta and Cyprus. To conclude, in the final chapter of this publication, we review key insights emerging from the various chapters, and summarize considerations for ecosystem management and sustainable development in Mediterranean Islands. We truly hope that this publication makes some contribution towards safeguarding the "magic' of Mediterranean islands, whilst embracing their dynamic characteristics.Published under the patronage of UNESCO and with the support of the Maltese National Commission for UNESCOpeer-reviewe

Vulnerability pathways to mental health outcomes in children and parents during COVID-19

We examined pathways from pre-existing psychosocial and economic vulnerability to mental health difficulties and stress in families during the COVID-19 pandemic. Data from two time points from a multi-cohort study initiated during the COVID-19 pandemic were used. Parents of children 6–18 years completed questionnaires on pre-COVID-19 socioeconomic and demographic factors in addition to material deprivation and stress due to COVID-19 restrictions, mental health, and family functioning. Youth 10 years and older also completed their own measures of mental health and stress. Using structural equation modelling, pathways from pre-existing vulnerability to material deprivation and stress due to COVID-19 restrictions, mental health, and family functioning, including reciprocal pathways, were estimated. Pre-existing psychosocial and economic vulnerability predicted higher material deprivation due to COVID-19 restrictions which in turn was associated with parent and child stress due to restrictions and mental health difficulties. The reciprocal effects between increased child and parent stress and greater mental health difficulties at Time 1 and 2 were significant. Reciprocal effects between parent and child mental health were also significant. Finally, family functioning at Time 2 was negatively impacted by child and parent mental health and stress due to COVID-19 restrictions at Time 1. Psychosocial and economic vulnerability is a risk factor for material deprivation during COVID-19, increasing the risk of mental health difficulties and stress, and their reciprocal effects over time within families. Implications for prevention policy and parent and child mental health services are discussed