bluuebunny/crossref_metadata_2025 huggingface dataset:
State of the art in radiation belt research
Authors: Summers Danny , Mann Ian R. , Baker Daniel N.
Published: December 2011

AGU Chapman Conference on Dynamics of the Earth's Radiation Belts and Inner Magnetosphere; St. John's, Newfoundland and Labrador, Canada, 17–22 July 2011 Earth's radiation belts were discovered by James Van Allen and colleagues in 1958 using data from the Explorer I satellite. Since then, the Van Allen belts have been under extensive theoretical and experimental investigation. Because highly energetic (relativistic) electrons generated in the outer radiation zone during geomagnetically disturbed times can damage orbiting satellites, Earth's radiation belts are regarded as a serious space weather hazard. The emerging science of space weather has fueled a resurgence of interest in radiation belt physics in the past 10 years. This will culminate in 2012 with the launch of NASA's Radiation Belt Storm Probes (RBSP) twin satellite mission, which will make in situ measurements of the radiation belts. Shortly after 2012 are also planned launches of the Japanese Energization and Radiation in Geospace (ERG) satellite and the Russian mission RESONANCE, both designed to probe Earth's radiation belts. Thus, 2012–2013 promises to be an exciting and pivotal period in radiation belt science.
Detrital remanent magnetization in the solar nebula
Authors: Fu Roger R. , Weiss Benjamin P.
Published: December 2011

We introduce the theoretical basis of a new form of remanent magnetization that likely formed on primitive bodies in the solar system. Accretional detrital remanent magnetization (ADRM) operates via “compass needle”‐type alignment of ferromagnetic solids with locally uniform background fields in the solar nebula. Accretion of coherently aligned magnetic particles should have formed aggregates up to centimeters in size with significant net magnetic moment. We quantify several processes that constrain the likelihood of ADRM formation, finding that rotational gas damping and background field intensities expected for the solar nebula are sufficient to mutually align magnetic particles with diameters between ∼30 μm and several cm. The lower bound is dictated by Brownian motion or radiative torque while the upper bound is set by aerodynamic torque on non‐spherical particles. Processes important for interstellar dust dynamics such as Larmor‐type precession and Purcell torque are less significant in the solar nebula. ADRM can be potentially observed as zones of coherent magnetization in primitive chondrites and may be detected by spacecraft magnetic field observations on the surfaces of small bodies. Observational identification and characterization of ADRM would constrain the strength and geometry of magnetic fields in the early solar system, the accretion process of sub‐meter sized objects, the formation regions of chondrite parent bodies, and the alteration history of chondritic components.
The effect of crystallite size and stress condition on the equation of state of nanocrystalline MgO
Authors: Marquardt H. , Speziale S. , Marquardt K. , Reichmann H. J. , Konôpková Z. , Morgenroth W. , Liermann H.-P.
Published: December 2011

We performed high-pressure synchrotron x-ray diffraction experiments on nanocrystalline (nc-) MgO compressed both under quasi-hydrostatic and non-hydrostatic conditions in a diamond-anvil cell. Data obtained under hydrostatic conditions show that nc-MgO (average crystallite size of 20 nm) is 8-9% more compressible than “bulk” MgO. Analysis of our results collected under non-hydrostatic conditions yields a bulk modulus that is about 27% larger than the one derived from the quasi-hydrostatic compression experiments. Thus, the apparent bulk modulus strongly depends on the experimental stress conditions.
Symbiotic performance of Mediterranean Trifolium spp. with naturalised soil rhizobia
Authors: Drew E. A. , Charman N. , Dingemanse R. , Hall E. , Ballard R. A.
Published: December 2011

Naturalised soil rhizobia that nodulate clover occur in high number and are known to vary in their symbiotic performance (SP) with subterranean clover (Trifolium subterraneum L.). However, the extent of suboptimal fixation across a range of other clover species is not well understood. T. subterraneum and nine other annual clover species of Mediterranean origin were evaluated for their SP in combination with the naturalised clover rhizobia in 71 Australian soils and five strains of Rhizobium leguminosarum bv. trifolii that have been used in the inoculants produced for clovers. The most probable number method, using subterranean clover as the trap plant was used to estimate the number of clover rhizobia in the soils. Ninety-two percent of soils tested contained more than 1000 rhizobia/g. An extract of each soil, or strain of rhizobia was used to inoculate plants growing in N-deficient media in the greenhouse. Plants were grown for 4 weeks after inoculation and shoot dry matter determined and expressed as a percentage of the ‘best’ soil rhizobia treatment, to provide a proportional measure of SP for each clover species. SP (mean of clover species) ranged from 96% with the current inoculant strain for annual clovers (WSM1325) down to 48% with former inoculant strain WU95. When inoculated with soils predominantly from mainland Australia, SP (mean of soil treatments) of the different Trifolium spp. was 55% (resupinatum), 53–47% (subterraneum), 50% (nigrescens), 49% (michelianum), 48% (isthmocarpum), 38% (hirtum), 35% (purpureum), 32% (vesiculosum), 25% (spumosum) and 21% (glanduliferum). Within each of the clover species, SP resulting from individual soil treatments ranged from 100% (by definition for the best soil treatment) down to close to zero. Trifolium glanduliferum formed nodules readily with the inoculant strains but nodulation was erratic with the rhizobia in many soils. It is therefore proposed that the naturalised rhizobia in many soils are unlikely to be inoculant strains. This research demonstrates symbiotic efficiency across annual clover species is compromised where diverse populations of clover rhizobia have naturalised in soils.
Radiation-use efficiency of irrigated biomass sorghum in a Mediterranean environment
Authors: Rinaldi Michele , Garofalo Pasquale
Published: December 2011

Mathematical crop simulation models are useful tools in predicting the potential yield of field crops in a specific environment. The main driving parameter used to estimate biomass accumulation in most of these models is radiation-use efficiency (RUE). Biomass sorghum (Sorghum bicolor L. Moench) is a crop that can be used for energy production (thermal and bioethanol chains) and a knowledge of its RUE in different water supply conditions can help to improve model simulations and evaluate crop diffusion.
A 3-year field experiment was carried out in Southern Italy where sorghum was submitted to four irrigated regimes based on actual crop evapotranspiration (ETc). In the first year ETc was measured with weighted lysimeters, while in the other 2 years it was estimated by means of estimated crop coefficient (Kc) and the reference evapotranspiration ET0.
The RUE, calculated as the slope of the first-order equation between dry biomass and intercepted photosynthetically active radiation along a crop cycle, showed an average of 2.91 ± 0.54 g MJ–1, even if the RUE proved to be closely correlated with crop water consumption. The latter ranged between 891 and 454 mm and the RUE increased 4.2 mg MJ–1 per mm of water used. A high crop interception of solar radiation was observed in sorghum, reaching its maximum efficiency 40 days after sowing.
To obtain high yielding yield biomass sorghum requires a large supply of water, as confirmed by the Kc calculated during the crop cycle, which resulted higher (especially in the development and middle stages) when compared with those reported in the FAO 56 Paper. The obtained RUE values also confirmed a high efficiency in biomass production of this crop, allowing for the introduction of biomass sorghum in the cropping systems of Mediterranean environments as an alternative crop for energy purposes, but with adequate irrigation water supply.
The impact of obesity on oocytes: evidence for lipotoxicity mechanisms
Authors: Wu Linda L.-Y. , Norman Robert J. , Robker Rebecca L.
Published: December 2011

Obesity can have detrimental effects on pregnancy rates in natural conceptions and also in women undergoing IVF or intracytoplasmic sperm injection (ICSI). This review summarises the most recent clinical literature investigating whether obesity impacts oocyte quality and early embryo growth. In other tissues, obesity leads to lipotoxicity responses including endoplasmic reticulum stress, mitochondrial dysfunction and apoptosis. Recent reports indicate that lipotoxicity is a mechanism by which obesity may impact oocyte quality.
The role of fatty acids in oocyte and early embryo development
Authors: McKeegan Paul J. , Sturmey Roger G.
Published: December 2011

Growing evidence suggests that endogenous and exogenous fatty acids play diverse roles in developing mammalian oocytes and early embryos. In this review, we describe some of the regulatory roles of fatty acids in early development, in addition to their metabolic functions. We focus initially on the provision of individual fatty acids, and then discuss how these might affect metabolism, oxidative stress, membrane composition, cell signalling events and gene expression. We propose that ongoing research should focus on physiologically relevant ratios and combinations of fatty acids, rather than isolated individual fatty acids, as their combined roles are both subtle and complex. Changing the ratio of specific fatty acids in the diet of animal models, and in vitro culture medium can cause significant dysregulation of cellular processes and development, an issue that extends to human fertility.
Improving fertility to timed artificial insemination by manipulation of circulating progesterone concentrations in lactating dairy cattle
Authors: Wiltbank Milo C. , Souza Alexandre H. , Carvalho Paulo D. , Bender Robb W. , Nascimento Anibal B.
Published: December 2011

This manuscript reviews the effect of progesterone (P4) during timed AI protocols in lactating dairy cows. Circulating P4 is determined by a balance between P4 production, primarily by the corpus luteum (CL), and P4 metabolism, primarily by the liver. In dairy cattle, the volume of luteal tissue is a primary determinant of P4 production; however, inadequate circulating P4 is generally due to high P4 metabolism resulting from extremely elevated liver blood flow. Three sections in this manuscript summarise the role of P4 concentrations before breeding, near the time of breeding and after breeding. During timed AI protocols, elevations in P4 are generally achieved by ovulation, resulting in an accessory CL, or by supplementation with exogenous P4. Elevating P4 before timed AI has been found to decrease double ovulation and increase fertility to the timed AI. Slight elevations in circulating P4 can dramatically reduce fertility, with inadequate luteolysis to the prostaglandin F2α treatment before timed AI being the underlying cause of this problem. After AI, circulating P4 is critical for embryo growth, and for establishment and maintenance of pregnancy. Many studies have attempted to improve fertility by elevating P4 after timed AI with marginal elevations in fertility. Thus, previous research has provided substantial insights into mechanisms regulating circulating P4 concentrations and actions. Understanding this prior research can focus future research on P4 manipulation to improve timed AI protocols.
Embryo death in cattle: an update
Authors: Diskin M. G. , Parr M. H. , Morris D. G.
Published: December 2011

For heifers, beef and moderate-yielding dairy cows, fertilisation generally exceeds 90%. In high-producing dairy cows, it may be lower and possibly more variable. The major component of embryo loss occurs before Day 16 following breeding, with emerging evidence of greater losses before Day 8 in high-producing dairy cows. Late embryo loss causes serious economic losses because it is often recognised too late to rebreed females. Systemic concentrations of progesterone during the cycles both preceding and following insemination affect embryo survival; too-high or too-low a concentration has been shown to be negatively associated with survival rate. Energy balance and dry matter intake during the 4 weeks after calving are critically important in determining conception rate when cows are inseminated 70 to 100 days after calving. More balanced breeding strategies with greater emphasis on fertility, feed intake and energy must be developed. Genetic variability for fertility traits can be exploited; genomic technology will not only provide scientists with an improved understanding of the underlying biological processes involved in fertilisation and the establishment of pregnancy, but could identify genes responsible for improved embryo survival. Their incorporation into breeding objectives would increase the rate of genetic progress for embryo survival. There is a range of easily adoptable management factors, under producer control, that can either directly increase embryo survival or ameliorate the consequences of low embryo survival rates. The correction of minor deficits in several areas can have a substantial overall effect on herd reproductive performance.
138 THE EFFECT OF FOLLICLE SUPERSTIMULATION ON mRNA LEVELS IN BOVINE OOCYTES COLLECTED BY OVUM PICKUP
Authors: Somfai T. , Imai K. , Kaneda M. , Akagi S. , Haraguchi S. , Watanabe S. , Inaba Y. , Geshi M. , Nagai T.
Published: December 2011

A previous study revealed that follicle superstimulation significantly improved the developmental competence of immature bovine oocytes collected by ovum pickup (OPU; Imai et al. 2008 Reprod. Fertil. Dev. 20, 182). The aim of the present study was to investigate the effect of follicle superstimulation on the expression of developmentally important genes in bovine oocytes collected by OPU. Follicular oocytes were collected by OPU without (OPU group) or after follicle superstimulation by FSH (FSH/OPU group) by using a 7.5-MHz linear transducer with needle connected to an ultrasound scanner according to Imai et al. (2008). In the FSH/OPU group, after dominant follicle removal from Holstein dry cows by OPU, a CIDR was inserted on Day 5 (dominant follicle removal = Day 0). Cows then received 30 mg of FSH twice a day from Days 7 to 10 in decreasing doses (6, 6, 4, 4, 3, 3, 2, 2 mg) by IM injection. Cloprostenol (PGF; Clopromate C; Sumitomo Pharmaceuticals Co., Tokyo, Japan; 0.75 mg) was administered in the morning of Day 9 (third day of superstimulation). Oocyte collection by OPU was performed 48 h after PGF administration (Day 11) by the aspiration of follicles larger than 5 mm in diameter. In the OPU group, 3-to-6-mm follicles were aspirated without any previous hormone treatment. In vitro oocyte maturation (IVM) was performed according to Imai et al. (2006 J. Reprod. Dev. 52(Suppl), 19–29). Gene expression was assessed before (0 h IVM) and after IVM (22 h IVM) by RT quantitative PCR. The following genes were investigated: GAPDH, G6PDH, ACTB, H2A, CCNB1, MnSOD, OCT4, SOX2, CX43, HSP70, GLUT8, PAP, GDF9, COX1, ATP1A1, CDH1, CTNNB1, AQP3, DYNLL1, DYNC 1/1 and PMSB1. In brief, mRNA was extracted from 20 oocytes per sample using Qiagen RNeasy Micro kit (Qiagen, Valencia, CA, USA). Gene expression was analysed by a Roche Light Cycler 480 device. The relative expression of each gene was normalized to ACTB. Three replications were performed. Data were analysed by ANOVA. At 0 h IVM, PAP and DYNC 1/1 were found to be down-regulated (P < 0.05) in the FSH/OPU group compared with the OPU group, whereas the rest of the studied genes showed similar expression in the FSH/OPU and OPU groups. At 22 h IVM, PAP and DYNC 1/1 remained down-regulated in FSH/OPU oocytes. However, at this time the expression of GDF9 appeared significantly higher (P < 0.05) in FSH/OPU oocytes than in OPU oocytes. The expression of GDF9 was found to decrease during IVM in both groups; however, this decrease was less drastic in FSH/OPU oocytes. The results suggest that follicle superstimulation caused reduced expression of mRNA levels of PAP and DYNC 1/1 irrespective of maturation status and it also moderated the reduction of mRNA levels of GDF9 during IVM.
14 EQUINE CLONING AND EMBRYO AGGREGATION: EFFECT OF BOVINE, PORCINE, FELINE AND EQUINE OOPLAST
Authors: Gambini A. , Jarazo J. , De Stefano A. , Karlanian F. , Salamone D.
Published: December 2011

The low number of horse slaughterhouses is one of the reasons for the limited availability of horse oocytes for research in cloning. The aim of our study was to assess the capability of equine, bovine, porcine, or feline ooplast to produce cloned embryos when equine cells are used as donor nuclei and to evaluate if embryo aggregation improves their development. Oocytes from mentioned species were collected from ovaries derived from slaughterhouses, except for cat ovaries that were obtained from ovariectomized queens. Oocytes were matured in TCM199 supplemented following standard protocols for each species. After maturation, cumulus and zona pellucida were removed. Enucleation was performed by aspiration of the metaphase plate under ultraviolet light. Donor cell and ooplast were attached by phytohemagglutinin treatment and then electrofused. Activation protocols were ionomycin for 4 min, except for porcine, which were electrically activated, followed by culture in 1.9 mM 6-DMAP for bovine, feline and porcine, except for equine: 1 mM 6-DMAP with 5 mg mL–1 of cycloheximide. Reconstructed embryos (RE) were cultured in SOF in the well of well system in 2 different groups: only one RE per well (1X) and three RE per well (3X, aggregated embryos, AE). Blastocysts derived from homospecific clones were transferred to synchronized mares. Cleavage and maximum development stage achieved of all experimental groups were assessed. In vitro development was compared using the chi-square test. In group 1X, a total of 64, 49, 38 and 145 RE were performed for porcine, bovine, feline and equine, respectively and in group 3X, 88, 48, 48 and 195 RE. Cleavage of cloned embryos ranged from 67 to 87%. Aggregated of homospecific equine clones showed the highest blastocyst rates (1X: 5.5%, 3X: 34%) and after embryo transfer (4 recipients for each group), an ongoing pregnancy (day 300, at the time of submission) was only achieved with aggregated embryo confirming the positive effect of embryo aggregation in these clones. The stages with higher developmental arrest of heterospecific nonaggregated embryos were 2 to 4 cells for porcine ooplast (23/64, 36%) and 4 to 8 cells for bovine and feline ooplast (37/49, 75% and 18/38, 47%, respectively). Blastocyst stage was only reached using feline ooplast (group I: 2/38, 5.26% and group II: 2/16, 12.5%). Heterospecific aggregated clones were able to achieve 16-cell stage, showing statistic differences compared with group 1X. As we reported previously, embryo aggregation shows benefits for homospecific equine clones, although more studies are needed to clarify if aggregation of heterospecific clones has the same effect. All heterospecific ooplasm was able to support embryo development. The stage of major developmental arrests was similar to embryonic genomic activation stage. Our results suggest that cat oocyte seems to be the best receptor to support equine cloned embryo development.
148 DIFFERENTIAL REGULATION OF CALCIUM TRANSPORT GENES, I.E., Na+/Ca2+ EXCHANGERS, TRANSIENT RECEPTOR POTENTIAL CATION CHANNEL 6 AND CALBINDINS, IN THE DIVERSE PLACENTAL TISSUES OF CALBINDIN-D9k AND -28k KNOCKOUT MICE VIA PUTATIVE STEROIDS
Authors: Koo T. H. , Jeung E. B.
Published: December 2011

During pregnancy, the placenta represents the establishment of an intimate connection between mother and fetus that is specific to mammals. Calbindins [Calbindin-D9k (CaBP-9k) and -D28k (CaBP-28k)] are proteins possessing EF-hand motifs that have a high affinity for Ca2+ ions and play an important role in the regulation and buffering of Ca2+ in the various tissues. Many types of calcium channels, intracellular calcium binding proteins, Na+/Ca2+ exchangers (NCX) and transient receptor potential cation channels (TRPV) have been found in the placenta. In this study, the calcium channel in maternal-fetal Ca2+ transport was investigated using the phenotypes of wild-type, CaBP-9k, CaBP-28k and CaBP-9k/28k knockout (KO) mouse models. Expressions of calcium transport genes in 3 dissected sections of placenta (MP: maternal, CP: central, FP: fetal) were examined by real-time RT-PCR (RT-qPCR) and Western blot analysis at gestational Day 19 in these mice. The level of TRPV6 mRNA and protein was highest in the MP and CP of CaBP-28k KO mice and the FP of CaBP-9k KO mice compared with other sections of KO mice. The level of CaBP-9k was significantly induced in CaBP-28k KO mice in MP, CP and FP compared with in WT mice, which levels were elevated from maternal to fetal sections. The expression of CaBP-28k mRNA and protein was reduced in CaBP-9k KO mice compared with WT in the 3 sections of placenta. The expression of NCX1 mRNA and protein was higher in all KO mice than in WT in MP and NCX1 was highest in CaBP-28k KO mice in CP, but strong in CaBP-9k KO mice in FP compared with other strains. These results indicate that TRPV6 and NCX1 participate in transferring calcium ions between maternal and fetal compartments and alteration of CaBP-9k/28k is involved in the intracellular Ca2+ buffering system among WT and KO mice. These results taken together indicate that TRPV6 and CaBP-9k genes may play a role as a key element in controlling placental calcium transport during pregnancy.
187 EFFECTS OF OVARY STORAGE TIME ON THE QUALITY AND MEIOTIC COMPETENCE OF CAT OOCYTES
Authors: Luu V. V. , Namula Z. , Kaedei Y. , Tanihara F. , Otoi T.
Published: December 2011

Unlike the oocytes of other species, cat oocytes have a unique characteristic in that they can mature in vitro after temporary storage at 5°C. Temporal storage of ovaries can aid in preserving oocytes from the ovaries of endangered felids that sometimes die suddenly in the field. The present study was conducted to evaluate the effects of the duration of cold storage of cat ovaries on the quality and meiotic competence of their oocytes. Domestic cat ovaries were collected from sexually mature queens (40 ovary pairs) at various stages of the reproductive cycle, after routine ovariohysterectomy performed at local veterinary clinics. After excision, the ovaries were stored at 5°C in physiological saline for 0, 1, 2, 3, 4 and 5 days until oocyte recovery. The cumulus–oocyte complexes with uniform and dark-pigmented ooplasm and more than 2 layers of cumulus cells were collected (n = 526) and then cultured for 24 h in maturation medium. This maturation medium consisted of tissue culture medium 199 supplemented with 4 mg mL–1 of bovine serum albumin, 0.1 IU mL–1 of human menopausal gonadotropin, 10 IU mL–1 of hCG, 1 μg mL–1 of 17 β-oestradiol and 50 μg mL–1 of gentamicin. The status of meiosis and fragmented chromatin in the oocytes after the 24-h maturation culture was assessed by terminal deoxynucleotidyl transferase dUTP nick end labelling and Hoechst 33342 staining. Data were analyzed using analysis of variance. The percentage of oocytes that reached metaphase II was greater for ovaries kept without cold storage (control group; 60.5%) than for ovaries kept for 1, 2, 3, 4 and 5 days in cold storage (maturation of 28.6, 38.3, 23.2, 1.6 and 2.2%, respectively; P < 0.05). In the cold storage group, the maturation rates (1.6–2.2%) of oocytes from ovaries stored for more than 4 days were significantly lower (P < 0.05) than those (23.2–38.3%) of oocytes from ovaries stored for less than 3 days. Moreover, oocytes with fragmented chromosomes after the maturation culture were not observed in the case of the control group, whereas 24.4 to 51.8% of the oocytes in the cold storage group had fragmented chromosomes, irrespective of the storage period. These results indicate that cold storage of cat ovaries decreases the meiotic competence of oocytes and influences the quality of oocytes matured in vitro.
47 ROLE OF INSULIN-LIKE GROWTH FACTOR-I ON THE FUNCTIONAL PARAMETERS AND FERTILITY OF OVINE FROZEN–THAWED SEMEN
Authors: Padilha R. , Magalhães-Padilha D. , Cavalcante M. , Almeida A. , Gastal M. , Nunes J. , Rodrigues A. P. , Figueiredo J. R. , Oliveira M.
Published: December 2011

The objective of the present experiment was to evaluate the effects of insulin-like growth factor-I (IGF-I) on the viability and fertility of ovine frozen/thawed semen. For evaluating the semen parameters, 5 rams were used. Before cryopreservation, semen samples from each ejaculate were divided into 4 aliquots and extended with Tris+ alone or supplemented with 1 of 3 different concentrations of IGF-I (50, 100 and 250 ng mL–1). Semen was evaluated immediately after thawing (T0), after 1 (T1) and 2 (T2) post-incubation at 37°C. The percentage of morphologically normal spermatozoa and live cells (fluorescence analysis-calcein and ethidium), acrosome integrity (NAR) and motility were analysed and hypoosmotic swelling tests (HOST) were performed to evaluate in vitro sperm survival. This experiment was replicated 5 times. In addition, AI was performed using 121 ewes to compare the optimal concentration of IGF-I versus Tris+ alone on fertility. Data for sperm parameters were analysed by 1-way ANOVA and the differences among groups were examined by Duncan's multiple range test. Pregnancy rates were analysed by the chi-square test of independence. After 1 and 2 h post-incubation, a decrease was observed in all groups in the percentage of motility, NAR and HOST when compared to the semen at T0. The motility rate was higher (P < 0.05) in the IGF-I 100 and IGF-I 250 groups when compared to the IGF-I 50 and Tris+ alone groups (76.2 and 75% vs 66.2 and 64.4%, respectively) at T0, after 1 h (67 and 63.6% vs 57.4 and 56.2%) and 2 h post-incubation (58.2 and 55.4% vs 48 and 47.2%). Furthermore, viability was higher (P < 0.05) in the IGF-I 100 and IGF-I 250 groups than in the IGF-I 50 and Tris+ alone groups (88.7 and 88.3% vs 76.6 and 77.6%, respectively) at T0. There was no difference (P > 0.05) in NAR or HOST among groups. No significant differences (P > 0.05) in fertility were observed between IGF-I 100 and Tris+ groups. In conclusion, the supplementation of Tris extender with IGF-I (100 and 250 ng mL–1) appears to be a successful way to preserve functional parameters of ovine sperm during cryopreservation.
49 USE OF DILUTION OF CRYOPRESERVED SEMEN IN FIXED-TIME ARTIFICIAL INSEMINATION OF MANGALARGA MARCHADOR MARES
Authors: Nogueira M. B. R. , Farinasso A. C. F. , Rezende A. C. , Pinto T. L. C. , Souza J. C.
Published: December 2011

Equine AI with frozen semen has become more frequent in reproduction centers, but osmotic shock during thawing is still a major problem as it impairs gamete viability and fertility. To overcome this, multi ultrasonographic (US) exams must be performed to ensure AI at the closest time to ovulation possible. The objective was to evaluate, in vivo, the effects of dilution of the cryoprotectant dimethylphormamide on the success of a fixed timed (20 h post-ovulation) AI protocol, in an attempt to reduce osmotic shock and the intense labour usually required during equine AI with frozen semen. Thirty-five Mangalarga Marchador mares were used in this trial. When dominant follicles reached at least 35 mm in diameter, ovulation was induced with 6 mg of equine gonadotrophin extract (EGE) intravenously. Artificial insemination was performed 20 h after ovulation according to 1 of the following protocols: no dilution (n = 14): three 0.5-mL straws were thawed and the semen deposited by a flexible rod at the uterine tip in the ipsilateral horn where the pre-ovulatory follicle was detected; or dilution (n = 21): three 0.5-mL straws were thawed as described and centrifuged after addition of 1.5 mL of BotuSêmen® extender (1:1 dilution). Pregnancy rates were evaluated between treatments, age and presence of intrauterine liquid (IUL) classes and period between ovulation and AI. Data were analysed as a binomial distribution with the GENMOD procedure (SAS, Cary, NC, USA). Pregnancy rate was higher (P < 0.05) for mares inseminated with diluted semen (42.9%) compared to those inseminated with no semen dilution (4.8%). Age and IUL class did not influence pregnancy rates. It can be concluded that reduction of osmotic stress through the dilution of cryopreserved equine semen increased pregnancy rates after AI. Semen dilution, as tested in this trial, yielded good pregnancy rates in a fixed-time AI protocol in mares, simplified mare management greatly and allowed the use of a fixed-time protocol successfully.
Supported by CNPQ, CAPES.
7 COMPARISON OF TIMED ARTIFICIAL INSEMINATION PROTOCOLS USING PROSTAGLANDIN F2α+ESTRADIOL OR PROSTAGLANDIN F2α+ESTRADIOL+GONADOTROPIN-RELEASING HORMONE IN DAIRY COWS
Authors: Jeong J. K. , Kang H. G. , Kim I. H.
Published: December 2011

This study compared pregnancy rates following 2 timed artificial insemination (TAI) protocols using PGF2α + oestradiol or PGF2α + oestradiol + GnRH in dairy cows. Four hundred fifty-five Holstein dairy cows, 2.2 ± 0.1 in parity, 148.3 ± 3.6 days in milk, with corpus luteum of greater than 20 mm diameter confirmed by ultrasonography (Tringa Linear with 5.0 MHz array transducer; Esaote Pie Medical, Maastricht, the Netherlands) were randomly divided into two treatments: an injection of 500 μg of cloprostenol, PGF2α analogue (Iliren cycle BP®, Intervet International GmbH, Unterschleissheim, Germany) and an injection of 2 mg of oestradiol benzoate (EB, SY Esrone, Samyang, Seoul, Korea) 36 h later (PGF2α + EB group, n = 257), or an injection of 500 μg of cloprostenol, an injection of 2 mg of EB 36 h later and an additional injection of 100 μg of gonadorelin, GnRH analogue (Godorel, Uni-Biotech Co., Ltd., Korea) 24 h later (PGF2α + EB + GnRH group, n = 198). All cows in the two groups received TAI 24 h after the EB injection. Pregnancy was determined at 40 to 50 days after TAI by using both ultrasonography and rectal palpation. Pregnancy rates between the PGF2α + EB and PGF2α + EB + GnRH groups were compared by the chi-square test using the SAS program (version 9.1: SAS Institute Inc., Cary, NC, USA). Pregnancy rate following TAI did not differ between the PGF2α + EB (32.7%) and PGF2α + EB + GnRH groups (34.9%; P > 0.05). In conclusion, addition of GnRH for TAI protocol using PGF2α + oestradiol did not improve pregnancy rate in dairy cows.
78 INTERFERON-τ SECRETION OF CRYOPRESERVED BOVINE TROPHOBLASTIC VESICLES DERIVED FROM IN VIVO
Authors: Hashiyada Y. , Takahashi H. , Imai K. , Geshi M.
Published: December 2011

The co-transfer of bovine trophoblastic vesicles (bTVs) prepared from in vivo recovered conceptuses is known to promote the successful implantation of embryos, which expected lower viability, through the effects of interferon-τ (IFN-τ) secreted by bTVs. We have reported that the pregnancy rate was improved for co-transferred embryos with frozen-thawed bTVs using the direct-transfer technique (Hashiyada et al. 2008, 41st SSR). However, the IFN-τ secretion level from cryopreserved bTVs is not well known. The objective of the present study was to measure concentration of IFN-τ released from frozen-thawed bTVs individually cultured in vitro. bTVs were prepared from elongating blastocysts 3 to 20 mm in length, following superstimulatory treatment and recovered on Day 16 post-AI, by dissection using a surgical blade. Each trophoblastic fragment, 1 to 1.5 mm in width, was cultured in a well of a 96-well plate using TCM-199 supplemented with 20% (v/v) fetal bovine serum and 0.1 mM β-mercaptoethanol. Formed vesicles after 24 or 48 h of culture were cryopreserved using D-PBS supplemented with 20% calf serum, 1.5 M ethylene glycol (EG) and 0.1 M sucrose or 1.8 M EG. After thawing, each bTVs was cultured for 2 days to compare IFN-τ secretion between the 2 cryoprotectants. Furthermore, transition of IFN-τ level was assessed in continuous culture until Day 10 (the day of thawing was defined as Day 0). The volume of culture medium was 100 μL well–1 day–1 until Day 2 and thereafter changed to 200 μL well–1 day–1 until termination. Exchange and collection of culture media were performed on Day 1, 2, 4, 6, 8 and 10. Collected culture media were stored at –30°C until use. IFN-τ was measured by RIA (Takahashi et al. 2005 Theriogenology 63, 1050–1060). Data were analysed by Student's t-test. Initial IFN-τ secretion from bTVs before cryopreservation did not differ between 24 and 48 h of culture period to form vesicles, 44.0 ± 2.9 (mean ± standard error of the mean, n = 64) and 52.8 ± 6.4 ng mL–1 (n = 27), respectively. IFN-τ secretion was no difference between the 1.5 M EG group and the 1.8 M EG group on Day 1 (41.2 ± 4.9 ng mL–1, n = 42 and 30.4 ± 2.2 ng mL–1, n = 31) and on Day 2 (38.0 ± 5.4 and 38.2 ± 4.5 ng mL–1), respectively. In the continuous culture group (n = 28), IFN-τ secretion tended to increase from Day 2 (25.2 ± 3.4 ng mL–1) to Day 4 (51.8 ± 12.3 ng mL–1) and 6 (55.4 ± 13.3 ng mL–1) (P < 0.05). However, this amount of IFN-τ on Day 6 significantly decreased on Day 8 (25.6 ± 2.7 ng mL–1; P < 0.05) and Day 10 (15.5 ± 2.2 ng mL–1; P < 0.01), gradually. These results indicate that cryopreserved bTVs could secrete IFN-τ at the same level as fresh bTVs on Day 4 to 6 after thawing and then these amounts of IFN-τ significantly decrease in vitro.
93 STRESS INDICATOR GENES EXPRESSION PATTERN IN BOVINE BLASTOCYSTS PRODUCED BY IN VITRO FERTILIZATION AND SOMATIC CELL NUCLEAR TRANSFER
Authors: Canepa M. J. , Mucci N. , Kaiser G. , Mutto A.
Published: December 2011

Reproductive biotechnologies, such as IVF and somatic cell nuclear transfer (SCNT) enable improved reproductive efficiency of animals. However, the birth rate from in vitro derived embryos still lags behind their in vivo counterparts. It is critical to develop an accurate evaluation and prediction system of embryo competence, for commercial purposes and for scientific research. Previous works have demonstrated that in vitro culture systems induce alterations in the relative abundance (RA) of diverse transcripts compromising embryo quality. The aim of this work was to analyse the RA of a set of genes involved in cellular stress (HSP70), endoplasmic reticulum (ER) stress (BiP and PSMB5) and apoptosis (Bax and Caspase-3), in bovine blastocysts produced by IVF, SCNT and their in vivo counterparts. Poly(A) RNA was isolated from 3 pools of 10 blastocysts per treatment and analysed by real-time PCR (RT–PCR). The results were normalized to the expression of the endogenous control (GAPDH). Data of mRNA expression was analysed using the InfoStat software (Universidad Nacional de Córdoba, Córdoba, Argentina). ANOVA, followed by Tukey multiple comparison test, was used for the analysis of differences in mRNA expression assayed by quantitative RT–PCR. Differences of P < 0.05 were considered significant. The RA of 3 stress indicators shown to be significantly increased in SCNT embryos compared with in vivo-derived blastocysts: by 23.9-fold for Bax, 12.1-fold for PSMB5 and 7.9-fold for Bip. No significant differences in RA of HSP70 and Caspase-3 gene transcripts were found. The increased expression of PSMB5 and BiP suggest that the SCNT embryos were under conditions of ER stress. When ER stress conditions persist, initiation of apoptotic processes is promoted. Furthermore, the significantly elevated transcript level of Bax could imply an initial activation of the apoptotic mechanisms, but the low levels of Caspase-3 revealed that the apoptotic caspase-cascade signalling system was not activated, hence not eliciting apoptosis, so far. With regard to IVF-derived embryos, no significant differences were detected in the RA of investigated genes compared with in vivo-produced blastocysts. Even though the embryos were morphologically comparable, mRNA expression pattern was dissimilar. Differential mRNA expression in bovine blastocysts obtained by different reproductive techniques produces blastocysts of divergent quality. We propose a new set of stress-indicator genes that give a widespread idea of bovine blastocyst quality. This study could complement morphological analysis to help develop an effective and accurate technique to diagnose embryo quality, towards improving the efficiency of artificial reproductive techniques.
Native Americans experienced a strong population bottleneck coincident with European contact
Authors: O'Fallon Brendan D. , Fehren-Schmitz Lars
Published: December 2011

The genetic and demographic impact of European contact with Native Americans has remained unclear despite recent interest. Whereas archeological and historical records indicate that European contact resulted in widespread mortality from various sources, genetic studies have found little evidence of a recent contraction in Native American population size. In this study we use a large dataset including both ancient and contemporary mitochondrial DNA to construct a high-resolution portrait of the Holocene and late Pleistocene population size of indigenous Americans. Our reconstruction suggests that Native Americans suffered a significant, although transient, contraction in population size some 500 y before the present, during which female effective size was reduced by ∼50%. These results support analyses of historical records indicating that European colonization induced widespread mortality among indigenous Americans.
Computational design of a symmetric homodimer using β-strand assembly
Authors: Stranges P. Benjamin , Machius Mischa , Miley Michael J. , Tripathy Ashutosh , Kuhlman Brian
Published: December 2011

Computational design of novel protein–protein interfaces is a test of our understanding of protein interactions and has the potential to allow modification of cellular physiology. Methods for designing high-affinity interactions that adopt a predetermined binding mode have proved elusive, suggesting the need for new strategies that simplify the design process. A solvent-exposed backbone on a β-strand is thought of as “sticky” and β-strand pairing stabilizes many naturally occurring protein complexes. Here, we computationally redesign a monomeric protein to form a symmetric homodimer by pairing exposed β-strands to form an intermolecular β-sheet. A crystal structure of the designed complex closely matches the computational model (rmsd = 1.0 Å). This work demonstrates that β-strand pairing can be used to computationally design new interactions with high accuracy.
Infliximab salvage therapy after failure of ciclosporin in corticosteroid‐refractory ulcerative colitis: a multicentre study
Authors: Chaparro M. , Burgueño P. , Iglesias E. , Panés J. , Muñoz F. , Bastida G. , Castro L. , Jiménez C. , Mendoza J. L. , Barreiro‐de Acosta M. , Gómez Senent S. , Gomollón F. , Calvet X. , García‐Planella E. , Gómez M. , Hernández V. , Hinojosa J. , Mañosa M. , Pérez Nyssen O. , Gisbert J. P.
Published: December 2011

Aliment Pharmacol Ther 2012; 35: 275–283

Background  Ciclosporin has proven to be effective in patients with corticosteroid‐refractory ulcerative colitis (UC). When therapy with this drug fails, infliximab can be considered to avoid colectomy. The efficacy and safety of this sequential approach remain unknown.

Aim  To assess the efficacy and safety profile of treatment with infliximab after failure of ciclosporin in patients with a corticosteroid‐refractory flare of UC.

Methods  Retrospective review of medical records of patients with a corticosteroid‐refractory flare of UC who did not respond to ciclosporin and received salvage therapy with infliximab within a month of discontinuing ciclosporin. The severity of the flare and response to the treatment were graded using the Lichtiger index. Cumulative rates of colectomy were calculated using Kaplan–Meier analysis. Cox regression analysis was performed to identify predictors of colectomy. To evaluate the safety profile of this treatment strategy, any adverse event occurring after the first infusion of infliximab was considered.

Results  The study population comprised 47 patients with corticosteroid‐refractory UC treated with infliximab after failure of ciclosporin. The median baseline Lichtiger index was 13. The mean time from the last ciclosporin dose to the first infliximab infusion was 6 days. After the first infliximab infusion, 13% of patients achieved remission, and 74% partial response. Of the 35 patients who received the third infliximab infusion, 60% achieved remission, and 37% partial response. Fourteen patients (30%) underwent colectomy. The rate of adverse events was 23%. One death occurred in a 40‐year‐old man who failed ciclosporin and infliximab and underwent surgery 10 days after the first infliximab infusion; he died of nosocomial pneumonia.

Conclusions  Treatment with infliximab makes it possible to avoid colectomy in two‐thirds of corticosteroid‐refractory UC patients in whom ciclosporin fails. However, the rates of adverse events and mortality mean that the decision to administer sequential therapy (ciclosporin–infliximab) should be taken on an individual basis.
The response of human ectomesenchymal dental pulp stem cells to cisplatin treatment
Authors: Seifrtová M. , Havelek R. , Ćmielová J. , Jiroutová A. , Soukup T. , Brůčková L. , Mokrý J. , English D. , Řezáčová M.
Published: December 2011

Seifrtová M, Havelek R, Ćmielová J, Jiroutová A, Soukup T, Brůčková L, Mokrý J, English D, Řezáčová M. The response of human ectomesenchymal dental pulp stem cells to cisplatin treatment. International Endodontic Journal, 45, 401–412, 2012.

Aim  To determine the response of dental pulp stem cells (DPSCs) to DNA‐damaging cytostatic cisplatin and compare it with the response of normal human dermal fibroblasts (HDFs).

Methodology  Dental pulp stem cells were exposed to 5, 10, 20 or 40 μmol L−1 of cisplatin. The proliferation of affected cells was assessed by a Z2 Counter and viability was assessed by means of a Vi‐Cell XR using Trypan blue exclusion staining. Cell cycle analysis and induction of apoptosis were performed by flow cytometry. Induction of apoptosis was determined by monitoring the activities of caspases. The expression of proteins was detected by electrophoresis and Western blotting. The descriptive statistics of the results was analyzed by Student’s t‐test.

Results  Dental pulp stem cells had a greater genotoxic stress response to cisplatin compared to HDFs. All three main Mitogen‐activated protein kinases (MAPK) families – extracellular signal‐regulated kinases (ERK), c‐Jun‐N‐terminal kinase (JNK) and p38 were activated after treatment of DPSCs with cisplatin. The activation of MAPK pathways was not observed in HDFs exposed to cisplatin. The exposure of DPSCs and HDFs to cisplatin provoked an increase in p53 and p21 expression and p53 phosphorylation of serine 15. Higher concentrations of cisplatin reduced the viability of DPSCs and HDFs and induced the activation of caspases 3/7 and 9.

Conclusion  Dental pulp stem cells had a greater genotoxic stress response to cisplatin compared to HDFs. Cisplatin in higher concentrations triggered activation of MAPK and apoptosis in DPSCs but not in HDFs.
Genetic variation and phenotypic plasticity of nutrient re‐allocation and increased fine root production as putative tolerance mechanisms inducible by methyl jasmonate in pine trees
Authors: Moreira Xoaquín , Zas Rafael , Sampedro Luis
Published: December 2011

1. Plant plastic responses to herbivore damage may include rapid, active reallocation of plant resources to reduce the impact of herbivory on future plant fitness. However, whether these inducible tolerance responses can be extended to pine trees and how these responses could be modulated by genetic and environmental factors remains unclear.

2. Biomass allocation and phosphorus (P) and nitrogen (N) concentrations in above‐ and below‐ground tissues were measured in Pinus pinaster juveniles belonging to 33 open‐pollinated families grown under two P availabilities (P‐deficient and complete fertilization). Measurements were taken 15 days after half of the plants received a foliar spray treatment of 22 mmol L−1 methyl jasmonate (MJ) to simulate above‐ground herbivore attack.

3. Simulated above‐ground herbivory promoted a strong preferential allocation of biomass below ground in the form of fine roots, leading to an almost two‐fold increase in fine root biomass in MJ‐treated plants and a significant reduction in above‐ground tissues and coarse roots. In addition, MJ signalling increased P and N concentrations in the shoots while reducing (P) or maintaining (N) concentrations in the roots. These results suggest that induced resource sequestration is not a generalized strategy in this pine species. Fine root biomass and concentration of N and P in plant tissues showed additive genetic variation, but responses to MJ signalling did not vary among families. Allocation of biomass to fine roots was not affected by P availability, whereas allocation of P to the shoot was more intense under complete fertilization.

4. Synthesis: Two new putative tolerance mechanisms inducible by MJ signalling may help to minimize the impact of above‐ground herbivore damage on the future fitness of young pine trees by (i) allocation of carbon to fine roots, this appeared to be a generalized strategy with weak environmental modulation and (ii) reallocation of P and N from roots to shoots, which was largely affected by P availability, and thus susceptible to greater phenotypic variation in heterogeneous environments. We provide evidence that changes in tolerance‐related traits are rapidly inducible by herbivory cues in this pine species. These results should be integrated with induced resistance responses to fully understand the costs and benefits associated with induced responses to herbivory.
Being reliable: issues in determining the reliability and making sense of observations of adults with congenital deafblindness?
Authors: Prain M. I. , McVilly K. R. , Ramcharan P.
Published: December 2011

Background  Most research into interactions with people who are congenitally deafblind involves observational data. In order for practitioners and researchers to have confidence in the findings of observational studies, researchers need to demonstrate that the processes employed are replicable and trustworthy. This paper draws on data from an observational study of adults with congenital deafblindness to illustrate issues in determining inter‐rater reliability, and interpreting observational data.

Method  Data from 34 10‐min observations of adults with congenital deafblindness and their interactions with support staff were assessed for inter‐rater reliability using percentage agreement calculated in three different ways and Cohen's κ.

Results  Large variation resulted from the different ways in which inter‐rater reliability was calculated, largely due to high levels of non‐occurrence of many behaviours in the coding tool used.

Conclusion  This study highlights the need to exercise caution when ascertaining the reliability of observational studies and demonstrates the value in using multiple methods for calculating inter‐rater reliability. The paper concludes with an examination of the potential merits of using consensus coding in observational studies of interactions with people with congenital deafblindness or profound intellectual and multiple disabilities.