The ham-5, rcm-1 and rco-1 genes regulate hyphal fusion in Neurospora crassa

Mutants of Neurospora crassa unable to participate in vegetative hyphal fusion (anastomosis) were isolated and characterized. From this analysis, three genes, rcm-1, rco-1 and ham-5, were identified and shown to be required for hyphal fusion. The rcm-1 and rco-1 genes are homologues of the Saccharomyces cerevisiae SSN6 and TUP1 genes, which encode a dimeric transcription factor in yeast. We demonstrate that in N. crassa the rcm-1 and rco-1 genes are required for hyphal fusion and normal hyphal morphology, and influence both asexual and sexual development. The ham-5 gene encodes a 1686 amino acid protein with two putative WD40 domains, which might participate in protein–protein interactions. ham-5 deletion mutants had a reduced rate of hyphal extension and altered hyphal morphology, and were unable to produce the conidial anastomosis tubes that are required for hyphal fusion during colony initiation

A rigid disulfide-linked nitroxide side chain simplifies the quantitative analysis of PRE data

The measurement of 1H transverse paramagnetic relaxation enhancement (PRE) has been used in biomolecular systems to determine long-range distance restraints and to visualize sparsely-populated transient states. The intrinsic flexibility of most nitroxide and metalchelating paramagnetic spin-labels, however, complicates the quantitative interpretation of PREs due to delocalization of the paramagnetic center. Here, we present a novel, disulfide-linked nitroxide spin label, R1p, as an alternative to these flexible labels for PRE studies. When introduced at solvent-exposed α-helical positions in two model proteins, calmodulin (CaM) and T4 lysozyme (T4L), EPR measurements show that the R1p side chain exhibits dramatically reduced internal motion compared to the commonly used R1 spin label (generated by reacting cysteine with the spin labeling compound often referred to as MTSL). Further, only a single nitroxide position is necessary to account for the PREs arising from CaM S17R1p, while an ensemble comprising multiple conformations is necessary for those observed for CaM S17R1. Together, these observations suggest that the nitroxide adopts a single, fixed position when R1p is placed at solvent-exposed α-helical positions, greatly simplifying the interpretation of PRE data by removing the need to account for the intrinsic flexibility of the spin label

Upaya Meningkatkan Hasil Belajar Matematika Materi Penjumlahan di Kelas V MI Muhammadiyah Sipedang Kecamatan Banjarmangu Kabupaten Banjarnegara dengan Menggunakan Metode The Power of Two

Skripsi ini dilatarbelakangi oleh pembelajaran matematika di Kelas V MI Muhammadiyah Sipedang Kecmatan Banjarmangu Kabupaten Banjar Negara dilakukan dengan menggunakan metode konvensional dengan ceramah, tanya jawab dan resitasi yang tentunya menjadikan siswa tidak mengalami pembelajarannya langsung dan mempersulit siswa dalam memahami materi matematika, Untuk itu, sebagai tenaga pendidik harus bisa mengurangi dan menghilangkan persepsi yang salah tersebut, dengan cara memilih metode pembelajaran yang lebih bervariasi dan tepat, Salah satu metode pembelajaran yang memenuhi kriteria adalah metode the power of two. Studi ini dimaksudkan untuk menjawab permasalahan: 1) bagaimana penerapan metode the power of two pada mata pelajaran matematika materi penjumlahan di kelas V MI Muhammadiyah Sipedang Kecmatan Banjarmangu Kabupaten Banjar negara? 2) apakah metode the power of two dapat meningkatkan hasil belajar matematika materi penjumlahan di kelas V MI Muhammadiyah Sipedang Kecmatan Banjarmangu Kabupaten Banjar negara? Permasalahan tersebut di bahas melalui penelitian tindakan kelas yang dilakukan melalui 2 siklus dengan setiap siklus tahapannya adalah perencanaan, tindakan, observasi dan refleksi. Hasil penelitian menunjukkan bahwa 1) Penerapan metode the power of two pada mata pelajaran matematika materi penjumlahan di kelas V MI Muhammadiyah Sipedang Kecamatan Banjarmangu Kabupaten Banjar negara dilakukan dengan melaksanakan pembelajaran yang memanfaatkan kekuatan dua siswa atau berpasangan untuk menyelesaikan masalah yang diberikan guru, selain itu pasangan tersebut juga mencoba menjawab pertanyaan dari pasangan lain sehingga terjadilah proses saling ketergantungan positif diantara pasangan. 2) Metode the power of two dapat mengurangi kesulitan belajar matematika materi penjumlahan di kelas V MI Muhammadiyah Sipedang Kecamatan Banjarmangu Kabupaten Banjar negara, hal ini terlihat dari hasil belajar yang di dapat siswa setelah melakukan tindakan dimana pada pra siklus ketuntasan ada 15 siswa atau 47%, pada siklus I ketuntasan ada 21 siswa atau 66% dan pada siklus II ketuntasan sudah mencapai 28 siswa atau 88%, begitu juga keaktifan belajar siswa juga mengalami kenaikan dimana pada siklus I ada 15 siswa atau 47 dan pada siklus II sudah mencapai 27 siswa atau 84

The performance of the 30-Gallon-Drum Neutron Multiplicity Counter at Rocky Flats Environmental Technology Site

In the fall of 1994, Rocky Flats Environmental Technology Site (RFETS) committed to offering approximately one metric ton of excess weapons plutonium for safeguards verification by the International Atomic Energy Agency (IAEA). At that time RFETS decided to offer cans of plutonium of varying purity, stored one or two to a package in 10- gal. drums, and contracted with the Los Alamos to obtain a 30-Gallon- Drum Neutron Multiplicity Counter (NMC) to measure these materials. A multiplicity counter was deemed necessary because of IAEA experience that the standard coincidence counting techniques routinely used in IAEA inspections would fail for plutonium-bearing materials of variable purity. RFETS also thought that such an instrument would be useful for their domestic safeguards needs

Ernährung bei angeborenen Stoffwechselerkrankungen — ein Spagat zwischen Genuss und Therapie

For many inborn metabolic diseases, a lifelong diet is a crucial part of the therapy since pharmacological therapy is available for only a few conditions and patients. The implementation of a low natural protein diet with a reduced intake of natural protein and the complementary use of synthetic amino acid mixtures is described using the examples of phenylketonuria and urea cycle disorders focusing on children and adolescents. For phenylketonuria, the amino acid supplement is free of phenylalanine whereas for urea cycle disorders, it exclusively consists of essential amino acids. The dietary treatment aims to maintain metabolic stability and to prevent accumulation of toxic metabolites. At the same time, the nutritional requirements to ensure growth and development must be met. Therefore, patients need to follow strict rules regarding the choice of food products. This restrictive therapy interferes with the desire for autonomy and the joy of eating and often results in a reduced quality of life.Following the diet is crucial for a favorable outcome. To meet its requirements, patients and their families are provided with training. It is a~great challenge not only to support the patients and their families in all practical aspects of dietary management, but also to motivate them to lifelong adherence in order to ensure the best possible outcome.Bei vielen angeborenen Stoffwechselkrankheiten ist eine lebensbegleitende Diät von Geburt an fester Bestandteil der Therapie. Alternative medikamentöse Therapieansätze stehen erst für einige wenige Patienten zur Verfügung. Am Beispiel der Phenylketonurie und der Harnstoffzyklusstörungen wird das Prinzip der eiweißdefinierten Diät mit dem Schwerpunkt auf Kinder und Jugendliche erläutert. Die Herausforderungen, die sich bei dieser Ernährungstherapie ergeben, werden aufgezeigt. Bei der eiweißdefinierten Diät erfolgt eine verminderte Zufuhr von natürlichem Protein, ergänzt durch die Gabe spezieller Aminosäuremischungen. Diese enthalten bei der Phenylketonurie kein Phenylalanin, bei den Harnstoffzyklusdefekten ausschließlich essenzielle Aminosäuren. Mithilfe der Diät soll zum einen eine gute metabolische Einstellung erreicht und die Anhäufung toxischer Metabolite vermieden werden. Zum anderen muss eine bedarfsdeckende Energie- und Nährstoffversorgung für das adäquate Wachstum und die Entwicklung des Kindes gewährleistet sein. Für die Patienten bedeutet dies, sich an restriktive Vorgaben bei der Lebensmittelauswahl halten zu müssen. Diese konkurrieren oft mit dem Bedürfnis nach Freiheit/Spontaneität und dem Genuss bei der Nahrungsaufnahme. Viele Patienten empfinden ihre Diät daher als drastische Einschränkung der Lebensqualität. Eine konsequente Umsetzung der Diät ist entscheidend für die Prognose der Erkrankungen. Hierfür bringen die Patienten und ihre Familien oft unterschiedliche Voraussetzung und Fähigkeiten mit. Für Therapeuten stellt es eine große Herausforderung dar, die Patienten nicht nur bei der praktischen Umsetzung ihrer Diät in allen Lebensabschnitten zu unterstützen, sondern auch zu einer langfristigen Adhärenz zu motivieren, um ein bestmögliches Outcome zu erreichen

The impact of capital structure on the decision to outsource with long term contracts

This paper analyzes how capital structure affects the firms’ strategic choice between outsourcing with long term contracts and outsourcing to the spot market. When outsourcing to the spot market firms are exposed to price uncertainty, whereas a long term contract allows them to set in advance the outsourcing price. We show that, to the extent that leverage and uncertainty can lead to financial distress costs in bad states of nature, firms may use long term contracts as a risk management device to hedge input price uncertainty.N/

The Yeast Cell Fusion Protein Prm1p Requires Covalent Dimerization to Promote Membrane Fusion

Prm1p is a multipass membrane protein that promotes plasma membrane fusion during yeast mating. The mechanism by which Prm1p and other putative regulators of developmentally controlled cell-cell fusion events facilitate membrane fusion has remained largely elusive. Here, we report that Prm1p forms covalently linked homodimers. Covalent Prm1p dimer formation occurs via intermolecular disulfide bonds of two cysteines, Cys-120 and Cys-545. PRM1 mutants in which these cysteines have been substituted are fusion defective. These PRM1 mutants are normally expressed, retain homotypic interaction and can traffic to the fusion zone. Because prm1-C120S and prm1-C545S mutants can form covalent dimers when coexpressed with wild-type PRM1, an intermolecular C120-C545 disulfide linkage is inferred. Cys-120 is adjacent to a highly conserved hydrophobic domain. Mutation of a charged residue within this hydrophobic domain abrogates formation of covalent dimers, trafficking to the fusion zone, and fusion-promoting activity. The importance of intermolecular disulfide bonding informs models regarding the mechanism of Prm1-mediated cell-cell fusion