Physiological and genomic variations in rice cells recovered from direct immersion and storage in liquid nitrogen

The use of cryoprotectants and slow cooling rates are routine procedures for the cryopreservation of plant cell lines. However, our results with rice (Oryza sativa L,, ev. Taipei 309) show that calli can be cryopreserved by direct immersion and stored in liquid nitrogen without any cryoprotection, the efficiency of recovery using this method, as well as a conventional method was generally increased with a previous abscisic acid (ABA) treatment. Following cryopreservation, calli demonstrated some differences with respect to unfrozen calli of the same lines, Thus, resistance to freezing stress (- 20 degrees C for 2 h) increased significantly in all lines tested, irrespective of their pre-incubation with ABA, Calli that had been directly stored in liquid nitrogen also demonstrated a higher competence for genetic transformation than their unfrozen counterparts, as indicated by the transient gene expression levels obtained after particle bombardment, These differences might lead to further biotechnological applications, A genetic analysis of amplified DNA polymorphisms was performed with three independent lines that had been subjected to four combinations of ABA treatment and direct immersion in liquid nitrogen, At the loci screened with the randomly amplified polymorphic DNA (RAPD) markers tested, the genetic variations among lines and among calli of the same line appear to bd more related to tissue-culture-induced somaclonal variation than to cryoselection.

Humoral and protective response of Indian major carps to immersion vaccination with Aeromonas hydrophila

Fry of the Indian major carps, Catta catla (Ham.), Labeo rohita (Ham.) and Cirrhinus mrigala (Ham.) were immunized at 4 and 8 weeks post hatching (wph) by direct immersion in a suspension (10 super(8) cells ml super(-1))of heat inactivated Aeromonas hydrophila. Following the same procedure, booster dose was administered 20 days after the first immersion. Antibodies as well as protective response produced in both the groups after the first and the booster immersion were different and significant (P<0.05). No significant difference was found between the species in the two age groups. The specimens immunized 8 wph showed higher antibody titres and protection than the 4 wph group. C. catla had higher relative percent survival followed by L. rohita and C. mrigala.

Osmocondicionamento de sementes de salsa (Petroselinum sativum Hoffm.) em diferentes potenciais hídricos

A germinação de sementes de salsa (Petroselinum sativum Hoffm.) é lenta e desuniforme, sendo a contagem do teste padrão de germinação recomendada aos 10 e 28 dias e a emergência em campo é relativamente longa, justificando o uso de técnicas que acelerem e uniformizem o processo germinativo: um método promissor é o osmocondicionamento. No presente trabalho, objetivou-se avaliar os efeitos dos diferentes potenciais de osmocondicionamento, com PEG 6000, na germinação de sementes de salsa e identificar o potencial osmótico ótimo para aumentar a germinação destas sementes. Sementes das cultivares Lisa e Portuguesa de dois lotes, adquiridas no comércio local foram osmocondicionadas pelo método de imersão direta das mesmas em soluções aquosas com potencial hídrico: 0,0, -0,5, -1,0 e -1,5 MPa, obtidos com a adição de PEG 6.000, sob aeração constante a 25ºC por 144 horas, como testemunha utilizaram-se sementes não osmocondicionadas. As variáveis analisadas foram: porcentagem de germinação (10 e 28 dias), velocidade de germinação e índice de velocidade de germinação. O osmocondicionamento aumenta a porcentagem e a velocidade de germinação de sementes de salsa, sendo que, o potencial osmótico indicado situa-se entre -1,0 e -1,5 MPa.

Analysis of Steroids using Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry-Mass Spectrometry (SPME-GC-MS-MS)

Direct immersion SPME-GC-MS-MS was used for the analysis of steroids in water at part-per-trillion(ppt) and lower concentrations. The method was validated and extended to real sample analysis. The method were linear from 0.01 to 5 ng/ml with precision less than 10% relative standard deviation for a steroid mixture at 1 ng/ml. Limit of quantitation and limit of detection was found to be 200- 1200 pg/L and 30-200 pg/L respectively and recoveries ranged from 88-103 %. To understand the extraction efficiency of the fiber, a depletion study was performed. The fiber/ sample partition coefficients for the steroids were determined to be 1.0 x 104 to 1.5 x 104 . The extraction was performed without derivatization or the use of an internal standard. SPMEGC-MS-MS effectively demonstrated ultra-trace level detection of steroids in water.

Vitrification of primordial germ cells using whole embryos for gene-banking in loach, Misgurnus anguillicaudatus

In gene-banking, primordial germ cells (PGCs), which are embryonic precursor cells of germ cells, are useful for cryopreservation because PGCs have a potential to differentiate into both eggs and sperm via germ-line chimera. Here, we have established vitrification methods for PGCs cryopreservation using 12- to 17-somite stage embryos in loach, Misgurnus anguillicaudatus, which were dechorionated, removed their yolk and injected with green fluorescent protein (GFP) -nos1 3'UTR mRNA to visualize their PGCs. In order to optimize cryopreservation medium for vitrification, the toxicity of cryoprotectants was analyzed. Different concentrations (2, 3, 4, 5 m) of dimethyl sulfoxide (DMSO), methanol (MeOH), ethylene glycol (EG) and propylene glycol (PG) as cryoprotectants were tested. Then, 5 m DMSO showed significantly-high toxicity. Based on this information, combinations called DMP (2 m (14.2% [v/v]) DMSO, 2 m (8.1% [v/v]) MeOH and 2 m (14.4% [v/v]) PG), DP (2 m (14.2% [v/v]) DMSO and 4 m (28.7% [v/v]) PG) and DE (2.1 m (15% [v/v]) DMSO and 2.7 m (15% [v/v]) EG) were evaluated for their toxicities and efficacy of PGCs cryopreservation using two types of equilibration step: direct immersion of cryopreservation media (one-step) and serial exposure to half and full concentration of cryopreservation media (two-step). Viable PGCs were obtained from post-thaw embryos which were cryopreserved by DP and DE with both 1- and 2-step equilibrations. Despite DP showing the highest toxicity, it gave the highest survival rate of embryonic cells after cryopreservation. When PGCs recovered from vitrified embryos were transplanted into host embryos at the blastula stage, the transplanted PGCs were able to migrate to a host genital ridge similarly as endogenous PGCs. It suggests that our methods could be useful to create a germ-line chimera for the production of gametes from PGCs of cryopreserved embryos.

Response and function of cutaneous mucosal and serum antibodies in barramundi (Lates calcarifer) acclimated in seawater and freshwater

Mucosal and serum antibody responses were studied in sibling barramundi (Lates calcarifer) acclimated in either seawater or freshwater following vaccination by intraperitoneal injection or direct immersion in an inactivated Streptococcus iniae vaccine. As expected, route of vaccination had a marked effect on immune response, with direct immersion resulting in low serum antibody levels against S. iniae by ELISA detected 21 days post vaccination at 26 degrees C, whilst a significant response was detected in mucus. A strong specific antibody response was detected in both mucus and serum 21 days following intraperitoneal injection. Fish acclimated in seawater prior to vaccination showed a markedly higher specific mucosal antibody response than sibling fish acclimated in freshwater, regardless of the route of vaccination, whilst the serum antibody response was not affected by salinity. Both mucosal and serum antibodies from fish in seawater and freshwater were capable of binding antigen at salinities similar to full strength seawater in a modified ELISA assay. These results indicate that this euryhaline fish species is riot only able to mount significant specific antibody response in cutaneous mucus, but that these antibodies will function in the marine environment. (c) 2005 Elsevier Ltd. All rights reserved.

Operator, organizational, and direct support maintenance manual including repair parts and special tools lists : heaters, space, radiant type, portable (type I, model M1941, solid fuel) FSN 4520-257-4877, (type II, model M1941, liquid fuel) FSN 4520-927-4214, (Yukon model M1950, solid or liquid fuel) FSN 4520-287-3353 : heaters, immersion, liquid fuel fired, for corrugated cans ....

"December 1969."

Direct Growth of Gold Nanorods on Gold and Indium Tin Oxide Surfaces: Spectral, Electrochemical, and Electrocatalytic Studies

The surfactant-assisted seed-mediated growth method was used for the formation of gold nanorods (GNRs) directly on gold (Au) and indium tin oxide (ITO) surfaces. Citrate-stabilized similar to 2.6 nm spherical gold nanoparticles (AuNPs) were first self-assembled on ITO or Au surfaces modified with (3-mercaptopropyl)-trimethoxysilane (MPTS) sol-gel film and then immersed in a cationic surfactant growth solution to form GNRs. The growth of GNRs on the MPTS sol gel film modified ITO surface was monitored by UV-visible spectroscopy. The ITO surface with the attached spherical AuNPs shows a surface plasmon resonance band at 550 nm. The intensity of this absorption band increases while increasing the immersion time of the AuNP-modified ITO surface into the growth solution, and after 5 h, an additional shoulder band around 680 nm was observed. The intensity of this shoulder band increases, and it was shifted to longer wavelength as the immersion time of the AuNP-modified ITO surface into the growth solution increases. After 20 h, a predominant wave at 720 nm was observed along with a band at 550 nm. Further immersion of the modified ITO surface into the growth solution did not change the absorption characteristics. The bands observed at 550 and 720 nm were characteristics of GNRs, corresponding to transverse and longitudinal waves, respectively. The AFM images showed the presence of GNRs on the surface of the MPTS sol gel modified ITO surface with a typical length of similar to 100-120 nm and a width of similar to 20-22 nm in addition to a few spherical AuNPs, indicating that seeded spherical AuNPs were not completely involved in the GNRs' formation. Finally, the electrocatalytic activity of the surface-grown GNRs on the MPTS sol gel film modified Au electrode toward the oxidation of ascorbic acid (AA) was studied. Unlike a polycrystalline Au electrode, the surface-grown GNR-modified electrode shows two well-defined voltammetric peaks for AA at 0.01 and 0.35 V in alkaline, neutral, and acidic pHs. The cause for the observed two oxidation peaks for AA was due to the presence of both nanorods and spherical nanoparticles on the electrode surface. The presence of spherical AuNPs on the MPTS sol gel film oxidized AA at more positive potential, whereas the GNRs oxidized AA at less positive potential. The observed 340 mV less positive potential shift in the oxidation of AA suggested that GNRs are better electrocatalysts for the oxidation of AA than the spherical AuNPs.

Designing blended learning in higher education : the neomillenial learner and mediated immersion

Blended learning as a term and a learning approach is still being refined, at times debated as a legitimate area of research, at times seen as the answer to the conundrum and challenges of the digital learner. Is it the Emperor’s new clothes? As Morrison (2003) suggests, blended learning could be seen as an uncertain or unsure strategy, or alternatively a way to find a solution to promises given for e-learning. Three case studies within this paper explore the possibilities of e-learning within a work-based framework. Elements of ‘neomillenial learning styles’ (Dede in Educause Quarterly vol 28 No 1 2005) reflected by students in postgraduate coursework programs provided the challenge and stimulation of designing and facilitating e-learning components, incorporating experiential or action learning with ‘associational’ approaches rather than linear ones. The journey to virtual simulations such as the postgraduate Newlandia incorporates the learner perspective, or how to activate neomillenial learning styles; blended learning with online and face-to-face community activist groups working for solutions to a water problem; and a virtual scenario which can appeal to and engage an internationalised user group. Do Dede’s neomillenial learners synthesise and process experiences rather than (or as well as) information? Is this mediated immersion a part of Newlandia’s applicability to the modern learner? The student teams of community activists and project managers described in the case studies incorporate a potent mix of learning styles, nationalities and backgrounds, expectations, interpersonal and technical skills and indicate a trend in millennial learners towards a community of knowledge which is collaborative, mobile and group-focused.

Reliability of surface EMG measurements of the quadriceps during maximal isometric contractions following water immersion

Background: The influence of water immersion on neuromuscular function is of importance to a number of disciplines; however, the reliability of surface electromyography (SEMG) following water immersion is not known. This study examined the reliability of SEMG amplitude during maximal voluntary isometric contractions (MVICs) of the vastus lateralis following water immersion.

Methods: Using a Biodex isokinetic dynamometer and in a randomized order, 12 healthy male subjects performed four MVICs at 60° knee flexion on both the dominant and nondominant kicking legs, and the SEMG was recorded. Each subject's dominant and nondominant kicking leg was then randomly assigned to have SEMG electrodes removed or covered during 15 min of water immersion (20°C–25°C). Following water immersion, subjects performed a further four MVICs.

Results: Intraclass correlation coefficient (ICC) and the relative standard error of measurement (%SEM) of SEMG amplitude showed moderate to high trial-to-trial reliability when electrodes were covered (0.93% and 2.79%) and removed (0.95% and 2.10%, respectively).

Conclusions: The results of the this study indicate that SEMG amplitude of the vastus lateralis may be accurately determined during maximal voluntary contractions following water immersion if electrodes are either removed or covered with water-resistive tape during the immersion.

Hardness and compressive strength of indirect composite resins: effects of immersion in distilled water

The aim of this study was to evaluate the effect of ageing in distilled water on the hardness and compressive strength of a direct composite resin Z100, a feldspatic porcelain (Noritake) and three indirect composites (Artglass, Solidex and Targis). For the Vickers hardness tests, five disk-shaped specimens (2 x 4 mm) of each material were prepared according to the manufacturers' instructions. The hardness tests were conducted using a Vickers diamond indentor. Compressive strength measurements were recorded on cylindrical specimens with a diameter of 6 mm and a length of 12 mm. The compression tests were carried out with a constant cross-head speed of 0.5 mm min(-1) on a mechanical test machine. For each material, 10 specimens were tested after 7 days of dry storage at 37 +/- 1 degreesC and 10 specimens were tested after water storage at 37 +/- 1 degreesC for 180 days. Noritake porcelain specimens showed higher hardness values than the composites. Among the composite materials, Z100 promoted the highest VHN values, regardless of the ageing periods. The results showed that Solidex and Z100 had the highest compressive strength values. Ageing in water reduced the hardness for all composites, but had no long-term effect on the compressive strength.

Investigation of nano-scale precipitation phenomena in Al-Fe and Al-Cu-(Fe) alloys processed via direct strip casting

The use of rapid solidification processes such as direct strip casting (DSC) is a good way to refine the Fe-intermetallics and decrease their detrimental effects. DSC creates out-ofequilibrium supersaturated microstructures. In this work, we explore the precipitation phenomena in direct strip cast Al-Fe and Al-Cu-Fe alloys and related corrosion and mechanical properties. The precipitates are characterised with differential scanning calorimetry and transmission electron microscopy. The corrosion performances are evaluated with immersion tests and weight loss measurements and the yield strength and ductility are estimated with tensile tests. A strong correlation between the microstructure and the bulk properties is revealed with a significant improvement of properties of DSC alloys.

Corrosion behaviour of direct current and active screen plasma carburised AISI 316 stainless steel in boiling sulphuric acid solutions

Active screen plasma is a recently developed plasma surface alloying technique, which has shown potential for addressing some drawbacks associated with conventional direct current plasma processes. In this study, the corrosion performance of untreated, direct current and active screen plasma carburised AISI 316 was investigated by immersion in a boiling solution of sulphuric acid. The experimental results show that the corrosion behaviour of expanded austenite produced by low temperature plasma carburising is controlled by the type and density of surface defects; the corrosion properties of the active screen plasma carburised material are superior to that produced by direct current plasma because of the significantly reduced edge effect and surface defects; and the bias level used in the active screen carburising treatment has a profound effect on the corrosion performance of the material. Based on the experimental results, the corrosion mechanisms involved are discussed.