Student Instruction Manual for Black and White Film Processing and Printing

For most subject matter the ideal classroom situation would allow a one-to-one relationship between instructor and student. In teaching basic photography this is especially true because of the great number of steps involved in producing a finished photograph and because each step must be done correctly to achieve good results. Time won\u27t permit the instructor to effectively follow each student through all the steps involved, and, ideally the student should be allowed to work at his or her own speed. The one-to-one relationship therefore, isn\u27t possible in most photography classes and, for that reason, something is needed to take the student through his laboratory work step-by-step. The problem is that there is no step-by-step guide in either pamphlet or text form that is detailed enough, yet simple enough to give the student the necessary help. Also, there is very little material available with which the student can compare his results without consulting the instructor. It is the primary objective of this study to create a step-by-step guide to be used by the student of basic photography in the performance of his laboratory requirements. It is hoped also that this guide will aid the instructor by offering complete instructions to the student and presenting graphically examples that can be used for comparison. This guide could also be used as a lesson plan by the instructor when planning a course in basic photography. The text is arranged in a logical order with headings covering each basic step. By using this paper and supplementary material on other phases of photography, an effective course for the beginner could be designed

Regulation of Arabidopsis root development by small signaling peptides

Plant root systems arise de novo from a single embryonic root. Complex and highly coordinated developmental networks are required to ensure the formation of lateral organs maximizes plant fitness. The Arabidopsis root is well-suited to dissection of regulatory and developmental networks due to its highly ordered, predictable structure. A myriad of regulatory signaling networks control the development of plant roots, from the classical hormones such as auxin and cytokinin to short-range positional signaling molecules that relay information between neighboring cells. Small signaling peptides are a growing class of regulatory molecules involved in many aspects of root development including meristem maintenance, the gravitropic response, lateral root development, and vascular formation. Here, recent findings on the roles of regulatory peptides in these aspects of root development are discussed.Christina Delay was supported by an Australia Postgraduate Award and GRDC Grains Industry Research Scholarship (GRS10329). This work was supported by an Australian Research Council grant to Michael A. Djordjeric and Nijat Imin (DP140103714)

The Physical State of Water in Dormant Bacteria

Anomalous behaviour of water confined in nanoscale gaps influences many biological and technological processes. However, due to the small size of confining structures, it is historically difficult to manipulate and study water’s dimension-dependent transport character. Experimental studies of nanoconfined water are generally limited to artificial test structures, and/or single-file channels, and so transport behavior of biologically nanoconfined water remains elusive. We utilize poroelastic bacterial spores coated onto a nanomechanical sensor to probe photo-thermal evaporative relaxation in a biological setting and report viscous water, 7 orders of magnitude larger than that of bulk liquid, and via thermodynamic investigations reveal an activation energy close to ice. Overall, these experiments characterize transport behaviour of nanoconfined water in vivo, and highlight the dramatic effects of nanoscale confinement on water that could impact myriad natural and synthetic processes. Following from this work, a hypothesis is pursued in which the bacterial lifecycle is intimately connected with transitions in the physical structure of the internal water. We expand an initial idea proposed in Science, 1960 by J.C. Lewis, N.S. Snell and H.K. Burr that the low water content of the spore core is accomplished through compressive contraction during development3. During sporulation, the genetic material is packaged with chelating chemicals within a special water-responsive, layered coating that electrostatically pulls the water out of the core. Together, these agents produce the extremely dehydrated, hydraulically tensioned, and stable spore-phase organism. During germinative re-awakening, an event lacking a complete mechanistic theory of sensation, the core is rehydrated and the organism subsequently reanimated. This work’s findings regarding the spore’s physically restrained but exchangeable water support the idea that the physical state of the water contributes significantly to tensioning the organisms into a ‘charged’ but dormant configuration. This dormant but spring-loaded phase of the bacterial lifecycle is subject to awakening by agents (nutrient or otherwise) which disrupt surface tension including amino acids, salts, surfactants, and hydrostatic pressures. In the least, it must be acknowledged that the slowed water observed herein enforces slowed biochemistry and thus dormancy. Taken together we present a picture where internal spore water, even that which is exchanged with the external environment, is nanoconfined and slowed under tremendous tension (negative pressure). The mechanism governing this slow water appears to be unlike that any previously described, the majority of which are typically based upon crystalline surfaces, the likes of which are not found in the spore. We consider that the spore water structure itself participates, in certain environments, in the signaling chain of the organism through stabilizing a delicately balanced and highly tensioned architecture. Presently we are working toward testing the hypothesis and expanding our understanding with new methods, including additional structural mutants and expanded biophysical techniques

Pressure vessel with improved impact resistance and method of making the same

A composite overwrapped pressure vessel is provided which includes a composite overwrapping material including fibers disposed in a resin matrix. At least first and second kinds of fibers are used. These fibers typically have characteristics of high strength and high toughness to provide impact resistance with increased pressure handling capability and low weight. The fibers are applied to form a pressure vessel using wrapping or winding techniques with winding angles varied for specific performance characteristics. The fibers of different kinds are dispersed in a single layer of winding or wound in distinct separate layers. Layers of fabric comprised of such fibers are interspersed between windings for added strength or impact resistance. The weight percentages of the high toughness and high strength materials are varied to provide specified impact resistance characteristics. The resin matrix is formed with prepregnated fibers or through wet winding. The vessels are formed with or without liners

Hybrid Wound Filaments for Greater Resistance to Impacts

A hybrid material containing wound filaments made of a hybrid of high-strength carbon fibers and poly(phenylene benzobisoxazole) [PBO] fibers is discussed. This hybrid material is chosen in an effort to increase the ability of the pressure vessel to resist damage by low-speed impacts (e.g., dropping of tools on the vessel or bumping of the vessel against hard objects during installation and use) without significantly increasing the weight of the vessel. While the basic concept of hybridizing fibers in filament-wound structures is not new, the use of hybridization to increase resistance to impacts is an innovation, and can be expected to be of interest in the composite-pressure-vessel industry. The precise types and the proportions of the high-strength carbon fibers and the PBO fibers in the hybrid are chosen, along with the filament-winding pattern, to maximize the advantageous effects and minimize the disadvantageous effects of each material. In particular, one seeks to (1) take advantage of the ability of the carbon fibers to resist stress rupture while minimizing their contribution to vulnerability of the vessel to impact damage and (2) take advantage of the toughness of the PBO fibers while minimizing their contribution to vulnerability of the vessel to stress rupture. Experiments on prototype vessels fabricated according to this concept have shown promising results. At the time of reporting the information for this article, research toward understanding and optimizing the performances of PBO fibers so as to minimize their contribution to vulnerability of the pressure vessel to stress rupture had yet to be performed

Nuclear localization of the mitochondrial factor HIGD1A during metabolic stress.

Cellular stress responses are frequently governed by the subcellular localization of critical effector proteins. Apoptosis-inducing Factor (AIF) or Glyceraldehyde 3-Phosphate Dehydrogenase (GAPDH), for example, can translocate from mitochondria to the nucleus, where they modulate apoptotic death pathways. Hypoxia-inducible gene domain 1A (HIGD1A) is a mitochondrial protein regulated by Hypoxia-inducible Factor-1α (HIF1α). Here we show that while HIGD1A resides in mitochondria during physiological hypoxia, severe metabolic stress, such as glucose starvation coupled with hypoxia, in addition to DNA damage induced by etoposide, triggers its nuclear accumulation. We show that nuclear localization of HIGD1A overlaps with that of AIF, and is dependent on the presence of BAX and BAK. Furthermore, we show that AIF and HIGD1A physically interact. Additionally, we demonstrate that nuclear HIGD1A is a potential marker of metabolic stress in vivo, frequently observed in diverse pathological states such as myocardial infarction, hypoxic-ischemic encephalopathy (HIE), and different types of cancer. In summary, we demonstrate a novel nuclear localization of HIGD1A that is commonly observed in human disease processes in vivo

On the uniqueness and global dynamics of AdS spacetimes

We study global aspects of complete, non-singular asymptotically locally AdS spacetimes solving the vacuum Einstein equations whose conformal infinity is an arbitrary globally stationary spacetime. It is proved that any such solution which is asymptotically stationary to the past and future is itself globally stationary. This gives certain rigidity or uniqueness results for exact AdS and related spacetimes.Comment: 18pp, significant revision of v

Papel da exclusão na resistência ao excesso de ferro em arroz

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High-efficiency genome editing via 2A-coupled co-expression of fluorescent proteins and zinc finger nucleases or CRISPR/Cas9 nickase pairs

Targeted endonucleases including zinc finger nucleases (ZFNs) and clustered regularly interspaced short palindromic repeats (CRISPRs)/Cas9 are increasingly being used for genome editing in higher species. We therefore devised a broadly applicable and versatile method for increasing editing efficiencies by these tools. Briefly, 2A peptide-coupled co-expression of fluorescent protein and nuclease was combined with fluorescence-activated cell sorting (FACS) to allow for efficient isolation of cell populations with increasingly higher nuclease expression levels, which translated into increasingly higher genome editing rates. For ZFNs, this approach, combined with delivery of donors as single-stranded oligodeoxynucleotides and nucleases as messenger ribonucleic acid, enabled high knockin efficiencies in demanding applications, including biallelic codon conversion frequencies reaching 30–70% at high transfection efficiencies and ∼2% at low transfection efficiencies, simultaneous homozygous knockin mutation of two genes with ∼1.5% efficiency as well as generation of cell pools with almost complete codon conversion via three consecutive targeting and FACS events. Observed off-target effects were minimal, and when occurring, our data suggest that they may be counteracted by selecting intermediate nuclease levels where off-target mutagenesis is low, but on-target mutagenesis remains relatively high. The method was also applicable to the CRISPR/Cas9 system, including CRISPR/Cas9 mutant nickase pairs, which exhibit low off-target mutagenesis compared to wild-type Cas9