bluuebunny/crossref_metadata_2025 huggingface dataset:
Expanding Roles: A Survey of Public Health Genetic Counselors
Authors: Powell Karen Potter , Hasegawa Lianne , McWalter Kirsty
Published: August 2010

According to the 2008 National Society of Genetic Counselors (NSGC) Professional Status Survey (PSS), 31 genetic counselor respondents reported spending at least 50% of their time in the area of public health. The NSGC Public Health Special Interest Group (PHSIG) had 49 dues‐paying members in 2009. The purpose of this study was to identify the work settings and public health activities in which genetic counselors participate. A novel online survey was disseminated over the NSGC PHSIG Listserv. Forty‐one percent (n = 13) of public health genetic counselor respondents worked in a university medical system, while 53% (n = 17) were grant‐funded and held a non‐clinical appointment. The most common public health activities included educating healthcare professionals (82%) and community members (61%), research (55%), grant writing (55%) and grant administration (36%). Most respondents (82%) reported learning certain public health skills outside of their genetic counseling training programs. Differences in work settings were found, with a significantly greater percentage of public health genetic counselors working in government agencies. Genetic counselors have opportunities to become involved in public health activities as the scope of public health genetics grows. Furthermore, genetic counseling competencies are compatible with the Institute of Medicine's “10 Essential Public Health Services.” The NSGC and genetic counseling training programs are encouraged to offer more public health learning opportunities for genetic counselors and genetic counseling students interested in this specialty area.
Crayfish learning abilities: how does familiarization period affect the capture rate of a new prey item?
Authors: Ramalho Ricardo Oliveira , Anastácio Pedro Manuel
Published: August 2010

This study explores the effect of the length of learning period on capture rate of a previously unfamiliar prey by an invasive freshwater crayfish (Procambarus clarkii). Juvenile crayfish were subjected to different periods of contact (learning period) with a larvae prey (Chaoborus sp.). The length of the learning period significantly affected the number of prey consumed by the predator. Our results indicate that the naive crayfish require less than 12 h to learn to maximize capture rate of this prey. The learning coefficient, adopted in the present study, may be useful in exploring predation capabilities of alien species in newly invaded habitats.
Crab and Cockle Shells as Catalysts for the Preparation of Methyl Esters from Low Free Fatty Acid Chicken Fat
Authors: Boey Peng‐Lim , Maniam Gaanty Pragas , Hamid Shafida Abd , Ali Dafaalla Mohamed Hag
Published: August 2010

The use of waste oils/fats, as well as catalysts from waste materials, for producing biodiesel via transesterification have been of recent interest. As such, in the present work, the transesterification of chicken fat using crab and cockle shells as a catalyst was attempted. X‐ray diffraction (XRD) and electron dispersive X‐ray (EDX) results show that, upon thermal activation, both shells transformed into CaO, the active ingredient that catalyzes the reaction. In addition, the catalytic performance of individual shells as well as the combination of both shells in various ratios was similar. Under the optimal reaction conditions of 4.9 wt% catalyst amount and 0.55:1 methanol to oil mass ratio, methyl esters conversion above 98% was achieved in 3 h. The chicken fat methyl esters that were produced were found to meet several key specifications of biodiesel based on EN 14214 and ASTM D6751 test procedures.
Carotid Angioplasty and Stenting is Safe in Women
Authors: Shobha Nandavar , Almekhlafi Mohammed A. , Pandya Anjali , Couillard Philippe L. , Morrish William F. , Wong John H. , Hill Michael D.
Published: August 2010

Background

Results of randomized controlled trials have shown that carotid endarterectomy poses greater perioperative risks to women than to men. There are limited studies regarding sex differences in carotid angioplasty and stenting.

Objectives

To compare male and female patients undergoing carotid stenting with regard to their intraprocedural complications and 30-day outcome.

Methods

We reviewed patients who underwent carotid stenting between 1997 and 2007 at our tertiary centre. Distal protection devices were used in all patients after 1999. Demographics, risk factors, intraprocedural complications, and 30-day outcomes were compared between female and male patients.

Results

Among 243 patients who underwent 255 procedures, 67 were women (27.6%). The mean (SD) age of the female patients was 72.2 ± 8.4 years and that of the male patients was 72.0 ± 9.6 years ( P = .83). The majority of patients had symptomatic carotid artery disease; 11 women (16.4%) and 30 men (16.0%) were asymptomatic. The following intraprocedural complications were noticed in female vs male patients: asymptomatic carotid and/or iliac dissections 7.5% vs 0% ( P = .001), minor stroke 0% vs 1.1% ( P = 1.00), major stroke 0% vs 0.5% ( P = 1.00), and cardiac dysrhythmias 3% vs 2.7% ( P = 1.00). At 30 days, the outcomes in women vs men were as follows: mortality 3.0% vs 3.2% ( P = 1.00), major stroke 3.0% vs 2.1 % ( P = .66), and minor stroke 3.0% vs 3.2% ( P = 1.00).

Conclusion

Although minor asymptomatic intraprocedural dissections were more common in women, we did not find any impact of sex on the 30-day outcome. We concluded that carotid stenting can be performed as safely in women as in men.
Doing good better? The differential subsidization of charitable contributions
Authors: Carmichael Calum M
Published: August 2010

This article introduces the practice and theory of subsidizing at different rates the private financial contributions made to different categories of charitable or publicly beneficial civic activities. It describes and compares the practices by which eight governments apply differential subsidies, and then summarizes guidelines for their design that can be inferred from optimal tax and expenditure theory. It does this in the hope that differential subsidies will receive greater attention in the public policy literatures that deal with financing the third-sector.
Population genetic structure of the prairie dog flea and plague vector, Oropsylla hirsuta
Authors: BRINKERHOFF R. JORY , MARTIN ANDREW P. , JONES RYAN T. , COLLINGE SHARON K.
Published: August 2010

Oropsylla hirsuta is the primary flea of the black-tailed prairie dog and is a vector of the plague bacterium, Yersinia pestis. We examined the population genetic structure of O. hirsuta fleas collected from 11 prairie dog colonies, 7 of which had experienced a plague-associated die-off in 1994. In a sample of 332 O. hirsuta collected from 226 host individuals, we detected 24 unique haplotype sequences in a 480 nucleotide segment of the cytochrome oxidase II gene. We found significant overall population structure but we did not detect a signal of isolation by distance, suggesting that O. hirsuta may be able to disperse relatively quickly at the scale of this study. All 7 colonies that were recently decimated by plague showed signs of recent population expansion, whereas 3 of the 4 plague-negative colonies showed haplotype patterns consistent with stable populations. These results suggest that O. hirsuta populations are affected by plague-induced prairie dog die-offs and that flea dispersal among prairie dog colonies may not be dependent exclusively on dispersal of prairie dogs. Re-colonization following plague events from plague-free refugia may allow for rapid flea population expansion following plague epizootics.
HARISH-CHANDRA MODULES OVER THE ℚ HEISENBERG–VIRASORO ALGEBRA
Authors: GUO XIANGQIAN , LIU XUEWEN , ZHAO KAIMING
Published: August 2010

In this paper, it is proved that all irreducible Harish-Chandra modules over the ℚ Heisenberg–Virasoro algebra are of the intermediate series (all weight spaces are at most one-dimensional).
The Texas German Dialect Archive: A Multimedia Resource for Research, Teaching, and Outreach
Authors: Boas Hans C. , Pierce Marc , Weilbacher Hunter , Roesch Karen , Halder Guido
Published: August 2010

This paper describes the organization of the Texas German Dialect Project (TGDP), which aims to document and archive the remnants of Texas German. The mission of the TGDP is (a) to document Texas German as it reflects the rich cultural and linguistic traditions of its residents; (b) to gather basic research information about linguistic diversity; (c) to provide linguistic information for public and educational interests, and (d) to use the collected materials for the improvement of educational programs. The paper gives a brief histor-ical overview of the development of the Texas German community and then describes the workflow of the TGDP. We also discuss how the Texas German Dialect Archive (TGDA) is currently used for linguistic research on new dialect formation, language contact, and language death. Since the open-ended sociolinguistic interviews contain a wealth of information on the history and cultural practices of the Texas German community, the archive is also of interest to historians and anthropologists. Finally, we show how the archive has been used for community outreach programs throughout central Texas.*
Empirical versus time stepping with embedded error control for density‐driven flow in porous media
Authors: Younes Anis , Ackerer Philippe
Published: August 2010

Modeling density‐driven flow in porous media may require very long computational time due to the nonlinear coupling between flow and transport equations. Time stepping schemes are often used to adapt the time step size in order to reduce the computational cost of the simulation. In this work, the empirical time stepping scheme which adapts the time step size according to the performance of the iterative nonlinear solver is compared to an adaptive time stepping scheme where the time step length is controlled by the temporal truncation error. Results of the simulations of the Elder problem show that (1) the empirical time stepping scheme can lead to inaccurate results even with a small convergence criterion, (2) accurate results are obtained when the time step size selection is based on the truncation error control, (3) a non iterative scheme with proper time step management can be faster and leads to more accurate solution than the standard iterative procedure with the empirical time stepping and (4) the temporal truncation error can have a significant effect on the results and can be considered as one of the reasons for the differences observed in the Elder numerical results.
Along‐arc variation in seismic velocity structure related to variable growth of arc crust in northern Izu‐Bonin intraoceanic arc
Authors: Obana Koichiro , Kamiya Shin'ichiro , Kodaira Shuichi , Suetsugu Daisuke , Takahashi Narumi , Takahashi Tsutomu , Tamura Yoshihiko
Published: August 2010

The Izu‐Bonin arc is an intraoceanic island arc where the Pacific plate subducts beneath the Philippine Sea plate. Along‐arc variation in thickness of the arc crust has been observed by previous active seismic surveys beneath the Izu‐Bonin arc. We have imaged three‐dimensional (3‐D) seismic velocity structures in the northern Izu‐Bonin arc using arrival time data of the earthquakes during 80 days of observations by ocean bottom seismographs and three permanent island seismic stations. Our 3‐D velocity model indicates heterogeneous structure in the mantle wedge along the arc. Low‐velocity anomalies related to upwelling flow in the mantle wedge are not uniform beneath the volcanic front. Low‐velocity anomalies extending down to the subducting slab beneath the volcanic front coincide with thicker parts of the arc crust north of Aoga‐shima and south of Sumisu‐jima. This coincidence suggests that heterogeneous mantle upwelling flow fundamentally controls the growth of the arc crust. Along topographic highs in the forearc, low‐velocity anomalies in the crust and uppermost mantle coincide with positive magnetic anomalies suggesting the presence of a remnant arc, providing further evidence of this view of arc crust formation.
Numerical modeling of landquakes
Authors: Favreau P. , Mangeney A. , Lucas A. , Crosta G. , Bouchut F.
Published: August 2010

The Thurwieser landslide that occurred in Italy in 2004 and the seismic waves it generated have been simulated and compared to the seismic signal recorded a few tens of kilometers from the landslide source (i.e., landquake). The main features of the low frequency seismic signal are reproduced by the simulation. Topography effects on the flowing mass have a major impact on the generated seismic signal whereas they weakly affect low‐frequency wave propagation. Simulation of the seismic signal makes it possible to discriminate between possible alternative scenarios for flow dynamics and to provide first estimates of the rheological parameters during the flow. As landquakes are continuously recorded by seismic networks, our results provide a new way to collect data on the dynamics and rheology of natural flows.
Groove-gratings to optimize the electric field enhancement in a plasmonic nanoslit-cavity
Authors: Chen Chang , Verellen Niels , Lodewijks Kristof , Lagae Liesbet , Maes Guido , Borghs Gustaaf , Van Dorpe Pol
Published: August 2010

We study the spectral properties of a triangular plasmonic nanoslit-cavity with periodic triangular grooves to optimize the field enhancement inside the nanoslit. This work is mainly based on numerical calculations and also partly supported by experimental evidence. In the nanoslit-cavity, we can distinguish following three main contributions to the field enhancement: electrostatic interaction in the nanoslit, surface plasmon polariton standing waves in the cavity and excitation, and reflection of surface plasmon polaritons by the grating. The importance of phase matching between surface plasmons generated at the nanoslit and the gratings is also investigated in order to optimize the local field intensity in the nanoslit.
Microcantilever dynamics in liquid environment dynamic atomic force microscopy when using higher-order cantilever eigenmodes
Authors: Kiracofe Daniel , Raman Arvind
Published: August 2010

Dynamic atomic force microscopy is currently evolving from a single to a multifrequency instrument for nanoscale imaging often employing higher-order microcantilever eigenmodes for improved resolution and force spectroscopy. In this work the authors study the fundamentals of cantilever dynamics and energy dissipation when soft cantilevers are driven at their second flexural eigenmode and interact with samples in liquid environments. Contrary to the conventional first eigenmode operation, second eigenmode operation in liquids is often dominated by a subharmonic response (e.g., one tap every four drive cycles) and there is an energy transfer to the first eigenmode creating a new channel of energy dissipation and compositional contrast.
Why are para-hydrogen clusters superfluid? A quantum theorem of corresponding states study
Authors: Sevryuk Mikhail B. , Toennies J. Peter , Ceperley David M.
Published: August 2010

The quantum theorem of corresponding states is applied to N=13 and N=26 cold quantum fluid clusters to establish where para-hydrogen clusters lie in relation to more and less quantum delocalized systems. Path integral Monte Carlo calculations of the energies, densities, radial and pair distributions, and superfluid fractions are reported at T=0.5 K for a Lennard-Jones (LJ) (12,6) potential using six different de Boer parameters including the accepted value for hydrogen. The results indicate that the hydrogen clusters are on the borderline to being a nonsuperfluid solid but that the molecules are sufficiently delocalized to be superfluid. A general phase diagram for the total and kinetic energies of LJ (12,6) clusters encompassing all sizes from N=2 to N=∞ and for the entire range of de Boer parameters is presented. Finally the limiting de Boer parameters for quantum delocalization induced unbinding (“quantum unbinding”) are estimated and the new results are found to agree with previous calculations for the bulk and smaller clusters.
Effect of postdeposition anneals on the Fermi level response of HfO2/In0.53Ga0.47As gate stacks
Authors: Hwang Yoontae , Engel-Herbert Roman , Rudawski Nicholas G. , Stemmer Susanne
Published: August 2010

The electrical characteristics, in particular interface trap densities, oxide capacitance, and Fermi level movement, of metal oxide semiconductor capacitors with HfO2 gate dielectrics and In0.53Ga0.47As channels are investigated as a function of postdeposition annealing atmosphere. It is shown, using both conductance and Terman methods, that the Fermi level of nitrogen annealed stacks is effectively pinned at midgap. In contrast, samples annealed in forming gas show a large band bending in response to an applied gate voltage and a reduced midgap interface trap density compared to those annealed in nitrogen.
Ultrafast dynamics of antiferromagnetic order studied by femtosecond resonant soft x-ray diffraction
Authors: Holldack K. , Pontius N. , Schierle E. , Kachel T. , Soltwisch V. , Mitzner R. , Quast T. , Springholz G. , Weschke E.
Published: August 2010

Femtosecond (fs) soft x-ray diffraction at the Eu-M5 resonance was employed to study the dynamics of antiferromagnetic (AFM) order in a thin film of the magnetic semiconductor EuTe after fs laser excitation. The AFM Bragg peak intensity displays an ultrafast decay with an upper limit for the time constant of (700±200) fs followed by fast recovery with (47±10) ps. Reciprocal space scans across the diffraction peak could be recorded with picosecond and fs time resolution, demonstrating that even at synchrotron slicing sources ultrafast studies of spatial magnetic correlations are feasible. The results show that fs dynamics of materials with complex order parameters can be addressed.
Systematic study of different transitions in high operating temperature quantum dots in a well photodetectors
Authors: Barve Ajit V. , Rotter Thomas , Sharma Yagya , Lee Sang Jun , Noh Sam Kyu , Krishna Sanjay
Published: August 2010

We report a systematic study of different transitions in quantum dots-in-a-well infrared photodetectors in order to optimize the signal to noise ratio of the detector. Bound to continuum transitions offer very high extraction probability for photoexcited electrons but poor absorption coefficient, while the bound to bound transitions have higher absorption but poorer extraction probability. Bound to quasibound transitions are optimum for intermediate values of electric fields with superior signal to noise ratio. The bound to quasibound device has the detectivity of 4×1011 cm Hz1/2 W−1 (3V, f/2 system) at 77 K and 7.4×108 cm Hz1/2 W−1 at 200 K, which is highest reported detectivity at 200 K for detector with long wave cutoff wavelength.
Surface-plasmon enhancement of band gap emission from ZnCdO thin films by gold particles
Authors: Yang W. F. , Chen R. , Liu B. , Gurzadyan G. G. , Wong L. M. , Wang S. J. , Sun H. D.
Published: August 2010

We present our study of the dependence of surface plasmon (SP) coupled band gap emission and defect emission on the sputtering time of gold particles on ZnCdO films. Eightfold enhancement of the band gap emission from ZnCdO thin films coated with Au particles is observed, while the defect emission is completely suppressed. The remarkable enhancement of the band gap emission is mainly attributed to the coupling between excitons in ZnCdO films and the SP of Au particles. While the suppression of the defect emission may be ascribed to a combined effect of the reduction in surface defects and the charge transfer from defect level to the Au Fermi level.
Simulation of junctionless Si nanowire transistors with 3 nm gate length
Authors: Ansari Lida , Feldman Baruch , Fagas Giorgos , Colinge Jean-Pierre , Greer James C.
Published: August 2010

Inspired by recent experimental realizations and theoretical simulations of thin silicon nanowire-based devices, we perform proof-of-concept simulations of junctionless gated Si nanowire transistors. Based on first-principles, our primary predictions are that Si-based transistors are physically possible without major changes in design philosophy at scales of ∼1 nm wire diameter and ∼3 nm gate length, and that the junctionless transistor avoids potentially serious difficulties affecting junctioned channels at these length scales. We also present investigations into atomic-level design factors such as dopant positioning and concentration.
Ultraviolet radiation effects on paramagnetic defects in low-κ dielectrics for ultralarge scale integrated circuit interconnects
Authors: Bittel B. C. , Lenahan P. M. , King S. W.
Published: August 2010

The electronic properties of low-κ interlayer dielectric and etch stop layers are important issues in ultralarge scale integrated circuits development. Leakage currents are critical problems that are not well understood. A topic of current interest is ultraviolet curing of these films. We report on electron spin resonance and electrical measurements of low-κ films with and without ultraviolet exposure. This work provides fundamental understanding of the deep level defects likely involved in leakage currents.
Ultrafast and Reversible Multiblock Formation by the SET-Nitroxide Radical Coupling Reaction
Authors: Kulis Jakov , Bell Craig A. , Micallef Aaron S. , Monteiro Michael J.
Published: August 2010

The single electron transfer-nitroxide radical coupling (SET-NRC) reaction has been used to produce multiblock polymers with high molecular weights in under 3 min at 50°C by coupling a difunctional telechelic polystyrene (Br-PSTY-Br) with a dinitroxide. The well known combination of dimethyl sulfoxide as solvent and Me6TREN as ligand facilitated the in situ disproportionation of CuIBr to the highly active nascent Cu0 species. This SET reaction allowed polymeric radicals to be rapidly formed from their corresponding halide end-groups. Trapping of these carbon-centred radicals at close to diffusion controlled rates by dinitroxides resulted in high-molecular-weight multiblock polymers. Our results showed that the disproportionation of CuI was critical in obtaining these ultrafast reactions, and confirmed that activation was primarily through Cu0. We took advantage of the reversibility of the NRC reaction at elevated temperatures to decouple the multiblock back to the original PSTY building block through capping the chain-ends with mono-functional nitroxides. These alkoxyamine end-groups were further exchanged with an alkyne mono-functional nitroxide (TEMPO–≡) and ‘clicked’ by a CuI-catalyzed azide/alkyne cycloaddition (CuAAC) reaction with N3–PSTY–N3 to reform the multiblocks. This final ‘click’ reaction, even after the consecutive decoupling and nitroxide-exchange reactions, still produced high-molecular-weight multiblocks efficiently. These SET-NRC reactions would have ideal applications in re-usable plastics and possibly as self-healing materials.
SG1 Nitroxide Analogues: a Comparative Study
Authors: Marchand Jessica , Autissier Laurent , Guillaneuf Yohann , Couturier Jean-Luc , Gigmes Didier , Bertin Denis
Published: August 2010

Due to a specific balance between steric, polar, and stabilization effects, SG1 nitroxide and its corresponding alkoxyamine BlocBuilder MA are now well recognized as two of the most potent compounds in nitroxide-mediated polymerization (NMP). In this work, alternatives to SG1, based on various aldehydes, were targeted using structure–reactivity relationships already developed by our group. Compared with SG1, we show that the substitution of the tert-butyl group on the carbon α to the aminoxyl function by a 2-ethylhexyl group led to a new nitroxide (ETHEXNO), which exhibited an half-life time at 120°C similar to SG1 and a slightly slower kd for the alkoxyamine (2–3 times lower than the SG1). The styrene polymerization mediated by the ETHEXNO nitroxide has a similar behaviour to the one mediated by the SG1 in terms of livingness and control but the kinetics is affected (2–3 times lower). Concerning the n-butyl acrylate polymerization, an unexpected overheating occurred at 120°C, which led us to perform the polymerization in toluene at 100°C. The slow kinetics impedes the use of this nitroxide as a good alternative to SG1 and shows that the structure of the SG1 nitroxide is already delicately optimized and finding good alternatives is not straightforward.
Synthesis of Core - Shell Nanoparticles with Polystyrene Core and PEO Corona from Core-Crosslinked Micelles by the RAFT Process
Authors: Duong Hien T. T. , Nguyen T. L. Uyen , Kumpfmüller Josef , Stenzel Martina H.
Published: August 2010

Core–shell nanoparticles have been synthesized by core crosslinking of micelles. The underlying block copolymer, poly(oligo(ethylene glycol methyl ether methacrylate))-block-polystyrene (POEGMA-b-PS), was synthesized successfully by the reversible addition–fragmentation chain transfer (RAFT) process, using POEGMA as a macro-RAFT agent. The block copolymers were self-assembled into micelles in aqueous media and the resulting micelles and the RAFT endgroup, located in the core of the micelle, were used for the subsequent crosslinking step using a crosslinker, divinyl benzene (DVB). The rate of the crosslinking reaction was found to be slow with less than 20% conversion being achieved after 72 h. Nevertheless, crosslinked micelles were obtained and only a small fraction of free block copolymers remained. Cytotoxicity tests confirmed the biocompatibility of the prepared core-crosslinked micelles. In addition the crosslinked micelles were taken up by L929 cells without causing any signs of cell damage.
Convenient Access to Hydroquinone and Quinone Derivatives from Cyclobutenedione Units
Authors: Nguyen Thanh V.
Published: August 2010

An important synthetic method providing access to a variety of heterocyclic and polycyclic quinones and hydroquinones is described. The key transformation involves the thermal ring expansion of cyclobutenedione derivatives to quinone/hydroquinone units. The synthetic utility and recent applications of this method in natural product synthesis are also discussed.
New approaches to superovulation in the cow
Authors: Bó Gabriel A. , Guerrero Daniel Carballo , Tríbulo Andrés , Tríbulo Humberto , Tríbulo Ricardo , Rogan Dragan , Mapletoft Reuben J.
Published: August 2010

There is continuing need to simplify bovine superovulation protocols without compromising embryo production. The control of follicular wave emergence and ovulation has facilitated donor management, but the most commonly used treatment, oestradiol, cannot be used in many parts of the world and mechanical removal of the dominant follicle is difficult to apply in the field. Other alternatives include gonadotrophin-releasing hormone (GnRH) or LH, but efficacy in groups of randomly cycling animals is variable. Another alternative is to increase the response to GnRH by inducing a persistent follicle and initiating FSH treatments following GnRH-induced ovulation. The number of transferable embryos following superovulation during the first follicular wave did not differ from that achieved 4 days after oestradiol benzoate and progesterone. To further simplify superovulation, FSH has been administered as a single intramuscular injection. Superovulation of beef donors with a single intramuscular injection of Folltropin-V (Bioniche Animal Health, Belleville, ON, Canada) diluted in a slow-release formulation resulted in embryo production comparable to that obtained using the traditional twice-daily protocol. The single intramuscular injection has the potential to reduce labour and handling and may be useful when handling stress is an impediment to success. These alternatives provide ways of facilitating widespread application of embryo transfer technologies.
Delivery of cloned offspring: experience in Zebu cattle (Bos indicus)
Authors: Meirelles Flávio V. , Birgel Eduardo H. , Perecin Felipe , Bertolini Marcelo , Traldi Anneliese S. , Pimentel José Rodrigo V. , Komninou Eliza R. , Sangalli Juliano R. , Neto Paulo Fantinato , Nunes Mariana Tikuma , Pogliani Fábio Celidonio , Meirelles Flávia D. P. , Kubrusly Flávia S. , Vannucchi Camila I. , Silva Liege C. G.
Published: August 2010

The production of a healthy cloned calf is dependent on a multitude of successful steps, including reprogramming mediated by the oocyte, the development of a functional placenta, adequate maternal–fetal interaction, the establishment of a physiological metabolic setting and the formation of a complete set of well-differentiated cells that will eventually result in well-characterised and fully competent tissues and organs. Although the efficiency of nuclear transfer has improved significantly since the first report of a somatic cell nuclear transfer-derived animal, there are many descriptions of anomalies concerning cloned calves leading to high perinatal morbidity and mortality. The present article discusses some our experience regarding perinatal and neonatal procedures for cloned Zebu cattle (B. indicus) that has led to improved survival rates in Nellore cloned calves following the application of such ‘labour-intensive technology’.
104 SURVIVAL AND APOPTOSIS RATES AFTER VITRIFICATION OF EARLY, EXPANDED, AND HATCHED CALF AND COW BLASTOCYSTS IN VITRO-PRODUCED USING CRYOTOP AS A DEVICE
Authors: Morató R. , Izquierdo D. , Paramio M. T. , Mogas T.
Published: August 2010

Two experiments were designed to determine the ability of 7 and 8 day in vitro-produced blastocysts to survive to the vitrification procedure. Embryos were classified as early blastocysts, expanded, or hatching/hatched blastocysts. Vitrification was done using cryotop devices as described Du et al. (2007). After warming, blastocysts were incubated for 3 h in SOF medium. In the first experiment, we examined the developmental competence of early blastocysts, expanded blastocysts, and hatching/hatched blastocysts after vitrification using the Cryotop method. In the second experiment, warmed blastocysts that had been vitrified on cryotops were fixed in 4% formaldehyde and incubated with TUNEL staining for detecting DNA damaged nuclei. The percentage of TUNEL positive and negative blastomeres was assessed by confocal microscopy. In all experiments cow and calf blastocysts were compared. When the results according to the developmental stage were analyzed, no differences in the survival rates after vitrification of expanded and hatched blastocysts were observed at Day 8 from cow and calf blastocysts. After warming, survival rates of 52.4 and 50% were noted in the groups of expanded and hatched blastocysts respectively from Day 8 cow blastocysts. Similar results were observed in the groups of expanded (54.5%) and hatched (59.4%) blastocysts from Day 8 calf blastocysts. When embryos were vitrified at Day 7, survival rates of 78.4 and 66.7% were observed after warming expanded and hatched blastocysts from cows. In calves, a significant increase in the survival up to 83.3 and 80% was observed after warming expanded and hatched blastocysts. The lowest survival rates were observed in early blastocysts (from 26 to 51%), particularly in those vitrified at Day 8 (≤40%). Following vitrification, cell death was monitored in blastocysts 3 h after warming by TUNEL labelling of cells with damaged DNA. The TUNEL staining procedure was undertaken on Day 7 calf (n = 23) and cow (n = 25) blastocysts, as well as on Day 8 calf (n = 22) and cow (n = 30) blastocysts. When taking into account the stage of blastocyst development, there was a trend toward higher DNA integrity index after warming of expanded and hatched blastocysts compared with early blastocysts in calf and cow groups. So, cell damage was minimal in those blastocysts vitrified at expanded and hatched stage and rates were comparable with those from control fresh blastocysts. These findings suggest that the Cryotop technique seems to be particularly useful for blastocysts presenting a high degree of expansion (expanded and hatched blastocysts), mainly those blastocysts vitrified and warmed at Day 7.
110 THE USE OF FORSKOLIN AND ITS EFFECT ON IN VITRO-PRODUCED BRAHMAN-SIRED EMBRYOS SUBMITTED TO SLOW COOL FREEZING OR VITRIFICATION
Authors: Pryor J. H. , Trant J. A. , Ponchirolli-Schneider C. B. , Looney C. R. , Long C. R. , Forrest D. W.
Published: August 2010

The objective of this study was to further test the lipolytic effect of 10 μM forskolin on developmental differences between bovine in vitro produced (IVP) embryos submitted to slow cool (SC) freezing or vitrification (VT). Previously reported (phase I) IVP embryo hatching rates for control embryos (62%) were no different than 10 μM forskolin (67%; Pryoretal et al. 2009 Reprod. Fertil. Dev. 21, 163). For phase II: on Day 6 post-fertilization (IVF = Day 0), 207 Brahman-sired viable embryos were evenly divided and cultured for 24 h in G2.5 medium (Vitrolife, Englewood, CO, USA) with or devoid of 10 μL forskolin (Sigma, St. Louis, MO, USA). On Day 7, compact morula (CM, n = 31), blastocyst (BL, n = 76), and expanded BL (XBL, n = 100) were washed in Vigro Holding Plus medium (Bioniche, Pullman, WA, USA) and randomly allocated to 4 treatment groups; control SC (CSC; no treatment, n = 52), 10 μM forskolin SC (FSC; n = 55), control VT (CVT; n = 49), and 10 μM forskolin VT (FVT; n = 51). All embryos were packaged in sterile 0.25-mL plastic straws. The SC embryos were submitted to Vigro Ethylene Glycol Freeze Plus medium (Bioniche) for 5 min before freezing at 0.5°C/min from -6°C to -32°C and plunging in LN2. Embryos were vitrified using a bovine VT kit (Bioniche): VS1, 3 min; VS2, 45 s in 15 μL; diluent, in straw with VS2 separated by air columns, vitrified in LN2 vapor 1 cm from liquid for 1 to 15 min before plunging. The SC embryos were air thawed 5 s and placed in 30°C H2O bath for 10 s. The VT straws were air warmed 10 s and then in 35°C H2O for 20 s prior to shaking them down to mix columns. All embryos were cultured in G2.5 for 24-h survival and 48-h hatching rates. All percentage data were transformed using arcsin square root function prior to analysis, and means were compared for statistical significance using Student’s t. For mean survival rates, FSC was different than CSC but showed no difference between FVT and CVT (81.7 ± 0.09, 42.6 ± 0.09, 59.4 ± 0.09, 49.0 ± 0.10, respectively (P < 0.01). There were no statistical differences for hatching rates for combined embryo stages (58.2 ± 0.10, 37.8 ± 0.10, 34.4 ± 0.10, 28.1 ± 0.11 for FSC, FVT, CSC, and CVT, respectively; P > 0.07). However, when comparing hatching rates of only the blastocyst stage embryos (n = 176), FSC was superior to CSC and CVT but not different than FVT (74.8 ± 0.11, 29.5 ± 0.11, 29.1 ± 0.11, 48.5 ± 0.11, respectively; P < 0.01). In conclusion, FSC yielded significantly higher survival and blastocyst hatching rates than CSC, but there were no differences between CVT and FVT for survival and FVT for blastocyst hatching rates. These results indicate that the addition of 10 μM forskolin to culture 24 h prior to freezing 7 d IVP Brahman-sired embryos can increase survival and blastocyst hatching rates.

The authors acknowledge support from the American Brahman Breeders Association.
120 SUCCESSFUL LAMBING AFTER SUPER-COOLING ULTRARAPID VITRIFICATION SHEEP MORULAE
Authors: Toishibekov Y. M. , Blackburn H. D.
Published: August 2010

The aim of this work was to establish alternative methods for sheep morulae cryopreservation by using vitrification by open pulled straw (OPS) methods and super-cooling ultra-rapid vitrification (SCURV). Both treatments used a vitrification solution (VS) of 20% (3.6 mol L-1) ethylene glycol (EG), 20% (2.4 mol L-1) dimethylsulfoxide (DMSO), 0.5 mol L-1 sucrose in DPBS with 10% BSA in both methods. In our experiment we used the Vit-Master™ (MTG, Germany). The super-cooled LN facilitates heat transmission between LN and the cryosolution interface, and this is efficient for bovine semen and blastocyst cryoconservation (Arav et al. 2002). By surgical flushing of 24 super stimulated ewes 121 transferrable morulae were harvested; 30 morulae were transferred fresh to synchronised recipients and the others were cryopreserved by OPS (n = 49) or SCURV (n = 42), respectively thawed or warmed, and transferred to recipients. Embryos were vitrified using the OPS method. They were first incubated in 50% VS for 2 min and then transferred for 30 s into 100% VS. Each embryo was loaded by touching a 1-μL drop with the straw, which was immediately submerged into and stored in liquid nitrogen. Warming was done by placing the narrow end of the straw into DPBS + 0.25M sucrose for 5 min. Embryos were then transferred into DPBS + 0.125 M sucrose for 3 min and finally to DPBS until transfer. The SCURV morulae were then exposed to 50 and 100% VS at 37°C for 2 min and 30 s, respectively. Embryos after saturation VS have been transferred by on a surface of a nylon loop (volume 20 μL, diameter 0.5 mm) and using negative pressure temperature of liquid nitrogen in the chamber for freezing with the VIT-Master. Thawing vitrified embryos was accomplished by placing the vitrified embryos in solutions of sucrose 0.25 and 0.125 with expositions of 2 and 3 min, accordingly. After embryos were thawed, only good quality embryos were transferred. Importantly, our data suggest that by using the SCURV method, the toxic elements contained in the cryopreservation solution can be reduced while maintaining a similar ability to produce viable morulae for implantation as the OPS method. Although further work on the developmental competence of embryos cryopreserved with the SCURV method are needed, these data suggest that the faster freeze rate and lower levels of cryoprotectants of SCURV are able to minimize ice crystal formation and should be further evaluated as a routine mechanism for cryopreserving sheep morulae.

Table 1.Effect vitrification and ultra-rapid super-cooling vitrification on the viability and lambing of sheep morulae
132 INDUCTION OF FIRST POSTPARTUM OVULATION AFTER ADMINISTRATION OF GnRH, ESTRADIOL BENZOATE, OR LH ASSOCIATED OR NOT WITH CALF REMOVAL IN NELORE COWS
Authors: Pinheiro V. G. , Oliveira A. C. S. , Cury J. R. L. M. , Barros C. M.
Published: August 2010

There are reports in the literature indicating that the presence of calf, body condition score, energy balance, number of births (multiparous v. primiparous), and breed are factors that influence the duration of postpartum anoestrus in beef cows. The purpose of the present study was to evaluate, during early postpartum, the time necessary for reestablishment of pituitary LH stocks, determined by the hypothalamic-pituitary axis responsiveness to exogenous administration of GnRH and estradiol benzoate (EB). Multiparous lactating Nelore cows (n = 51) were kept in Brachiaria brizantha pasture. The animals were randomly allocated in 8 groups, according to the hormonal treatment: EB Group (1.0 mg of EB, i.m. Estrogin®, Farmavet, Sao Paulo, Brazil; n = 7), EB and calf removal (CR) group (EB/CR, calves were removed at the time of birth, n = 4), EB/SUP group (cows were supplemented with a balanced diet, based on cotton meal and ground corn, from the beginning of the experiment until ovulation), GnRH group (100 μg, licereline, i.m. Gestran Plus®, ARSA SLR, Buenos Aires, Argentina; n = 7), GnRH/CR group (n = 4), GnRH/SUP group (n = 8), LH group (12.5 mg, i.m. Lutropin® Bioniche, Ontario, Canada; n = 7), and control group (did not receive any hormone to induce ovulation or diet supplementation, n = 5).The hormones were administered weekly, from 7 days postpartum (±5 days) until the occurrence of the first ovulation, which was determined by the presence of CL during weekly ovarian ultrasonography (Aloka 900, Tokyo, Japan, 7.5 MHz probe). The data were analyzed by ANOVA. On average (±SEM) the first ovulation occurred 86.7 ± 0.5 (EB); 19.7 ± 0.6 (EB/CR); 57.8 ± 0.4 (EB/SUP); 44.7 ± 0.5 (GnRH); 25.9 ± 0.6 (GnRH/CR); 32.8 ± 0.4 (GnRB/SUP); 42.4 ± 0.5 (LH); and 59.3 ± 0.5 (control) days postpartum. There were significant differences between groups: EB v. EB/SUP (P < 0.01), EB v. EB/CR (P < 0.01), EB v. control (P < 0.04), EB v. GnRH (P = 0.01), and there was a tendency between groups: GnRH v. GnRH-SUP (P = 0.10) and LH v. control (P = 0.10). The first ovulations were detected from the second week postpartum (animals from Groups GnRH and EB/CR) until the last ultrasound examination on Day 120 postpartum (Group EB). The results indicate that from the second week postpartum there is sufficient LH in the pituitary to induce ovulation after GnRH or EB administration. However, the cows from EB group ovulated later than animals from the other groups, possibly due to the sensitivity of hypothalamus to negative feedback of estrogens, inhibiting the pre-ovulatory LH surge. Additionally, calf removal and food supplementation reduced in 2 to 4 weeks the time of the first postpartum ovulation induced by GnRH or EB.

Fellowship from FAPESP. Supported from FAPESP (Sao Paulo, Brazil).
139 STIMULATION OF BOVINE TROPHECTODERM MIGRATION BY FIBROBLAST GROWTH FACTORS
Authors: Giassetti M. I. , Yang Q. E. , Ealy A. D.
Published: August 2010

Following hatching, bovine and ovine blastocysts elongate into tubular and then filamentous conceptuses that remain free-floating for several days before attaching to the uterine lining. Elongation is marked by trophectoderm proliferation and changes in trophectoderm shape. The ultimate goal of this work is to identify uterine- and conceptus-derived factors that control peri-attachment conceptus development in cattle. Fibroblast growth factors (FGF) encompass a large family of mitogens, morphogens, and angiogenic factors produced by various tissues, including the bovine/ovine endometrium and conceptus. FGF2 and FGF10 are of particular interest because uterine production of FGF2 and conceptus production of FGF10 intensify as elongation takes place in cattle and sheep. The objective of this work was to determine if FGF2 and FGF10 stimulate bovine trophectoderm migration during culture. Migration assays were conducted with CT1 cells, a trophectoderm line established from a bovine in vitro-produced blastocyst outgrowth. Cells were seeded on 8-μm pore Transwell inserts (Corning Inc., Corning, NY, USA; 50,000 cells/insert) and submerged in serum-free DMEM containing treatments (0, 0.5, 5, 50, and 500 ng mL-1 of recombinant bovine FGF2 or human FGF10). After 12 h, cells that migrated onto the lower surface were fixed, stained, and processed for counting using epifluorescence microscopy. Migrated cells were counted in 5 non-overlapping locations on each of 4 replicate Transwell inserts for each treatment. Experiments were repeated on at least 3 different occasions. Analysis of variance was completed. Differences in individual means were partitioned further by completing pair-wise comparisons. Supplementation with 5 or 50 ng mL-1 of FGF2 increased (P = 0.06 and P = 0.002, respectively) migration of CT1 cells when compared with controls (327 ± 17 or 485 ± 40 cells, respectively, v. 162 ± 16 cells). Supplementation with 500 ng mL-1 of FGF2 further increased (P < 0.02) migration when compared with controls and cells exposed to lower levels of FGF2 (548 ± 116 cells). FGF10 also stimulated CT1 migration. Supplementation with 0.5 ng mL-1 of FGF10 increased (P = 0.06) cell migration v. controls (254 ± 48 v. 184 ± 24 cells). Supplementation with 5 ng mL-1 further increased (P < 0.007) cell migration (373 ± 29 cells). Exposure to greater FGF10 concentrations did not further enhance cell migration. To summarize, both FGF2 and FGF10 promoted CT1 migration, suggestive of a potential function in regulating trophectoderm development, differentiation, and/or morphogenesis during peri-attachment conceptus development. FGF10 appeared to be more potent than FGF2 at mediating CT1 migration. The reason for this disparity has not been resolved but likely involves differences in ligand affinities to certain receptor subtypes.

This project was supported by NRI Competitive Grant No. 2008-35203-19106 from the USDA-CSREES.
147 QUALITY OF PORCINE EMBRYOS CULTURED WITH HYALURONAN
Authors: Gajda B. , Grad I. , van der Tuin E. , Smorag Z.
Published: August 2010

Hyaluronan (HA) is a high molecular weight polysaccharide found in the mammalian follicular, oviduct, and uterine fluids. When HA is added in maturation and culture media, it improves the developmental potential of bovine (Stojkovic M et al. 2002 Reproduction 124, 141-153; Palasz AT et al. 2008 Zygote 16, 39-47), and porcine oocytes (Sato E et al. 1990 Mol. Reprod. Dev. 26, 391-397) and embryos (Miyano T et al. 1994 Theriogenology 41, 1299-1305). Physiological concentration of HA in follicular, oviductal, and uterine fluids of pigs range from 0.04 to 1.83 mg mL-1 (Kano K et al. 1998 Biol. Reprod. 58, 1226-1232). The aim of the present study was to investigate the effect of different concentrations of HA on the development and quality of cultured porcine embryos. Zygotes from superovulated pigs were cultured in vitro in NCSU-23 medium supplemented with BSA and 0 mg mL-1 (control group), 0.25 mg mL-1 (Exp. Group 1), and 0.5 mg mL-1 (Exp. Group 2) of HA (Animal Pharma BV). Experiments were replicated 3 times with 30 to 40 embryos per each treatment group. Embryos were cultured up to the blastocyst stage at 39°C in an atmosphere of 5% CO2 in air, in 4-well plastic dishes, which contained approximately 0.8 mL of the NCSU-23 medium. Embryo quality criteria were cleavage (on Day 2 after in vitro culture), morula (on Day 4) and blastocyst (on Days 6 to 8) rates, total cell number per blastocyst, and degree of apoptosis (on Day 7) assessed by TUNEL method. Results were analyzed by ANOVA test. There was no difference in percentage of cleaved embryos between control and treated Group 1 and 2.The proportion of embryos developed to the morula and blastocyst stage was 80.0 and 60.0% for Group 1 (0.25 mg of HA), 73.7 and 44.7% for Group 2 (0.5 mg of HA), and 73.4 and 46.7% for control, respectively (difference NS). Supplementation with HA did not increase the cell number of the blastocysts but significantly reduced number of apoptotic nuclei from 2.0 for control to 0.7 (P < 0.01) and 0.6 (P < 0.01) for Group 1 and 2, respectively, and apoptotic index from 9.70 for control to 3.01 (P < 0.05) and 1.95 (P < 0.05) for Group 1 and 2, respectively. These results indicate that supplementation of culture medium NCSU-23 with HA improves the quality (assessed by apoptotic index) of pig embryos but does not increase the total cell number in pig blastocysts as reported by Kim HS et al. 2005 (Theriogenology 63, 1167-1180). However, further research to test the HA’s effect on cryopreservation of in vitro and in vivo produced pig embryos are needed.