bluuebunny/crossref_metadata_2025 huggingface dataset:
73EFFECT OF CALF RECLONING ON EMBRYO AND FETAL SURVIVAL
Authors: Salamone D.F. , Santos C.B. , Barañao J.L. , Bussmann J.L. , Artuso J. , Mujica I. , Munar C.J. , Berra G. , Melo C.
Published: February 2004

In a large-scale cloning program destined to produce transgenic animals, it is very important to incorporate well-characterized transgene integration and gene expression. However, after non-homologous transfection, a wide variety of transgene copies are introduced, and these occur in different chromosome locations. Recloning a selected first-generation transgenic calf offers the opportunity to increase the homogeneity among transgenic animals. Calf recloning was performed in an experiment in which the survival rate was evaluated after a second round of cloning from transgenic umbilical cord and ear calf fibroblasts. The original genetically modified fetal cell line that produced the clones was used as control. Oocytes were aspirated from slaughterhouse ovaries and matured in TCM-199+5% FCS at 39°C for 24h. Matured oocytes were denuded by vortexing for 3min in TL HEPES with 1mgmL−1 bovine testis hyaluronidase. Metaphases were assessed and oocytes were enucleated by visualization with Hoechst 33342 (5μgmL−1) under UV light (<6s). A fetal fibroblast cell line was initially established from a 75-day old Jersey female fetus. Genetically modified cells were isolated after selection with geneticin for 10–15 days following liposome transfection with a DNA construct containing a selectable neomycin resistance gene. Following nuclear transfer with these transgenic cells, new cell lines were isolated from umbilical cord and ear fibroblasts obtained from one of the cloned-transgenic calves so-produced. Donor cells from all three sources were used for nuclear transfer at G0/G1 cell cycle stages and were fused to enucleated oocytes by an electrical pulse. After 3h, activation was induced by incubation in TL-HEPES with 5μM ionomycin for 4min and then 2mM 6-DMAP for 3h. The oocytes were then washed with TL- HEPES and cultured in SOF medium with an atmosphere of 5% CO2+5% O2+90% N2. Development to blastocyst stage (Days 7 to 9) was recorded. One or two blastocysts were transferred non-surgically per recipient cow, and pregnancies at 30 days or 60 days were determined by ultrasonography. All data were analyzed by chi-square test. Seven births were obtained from the original fetal cell line, one birth was obtained from recloned umbilical cord and four pregnancies are in the last third of gestation from recloned ear fibroblasts. Development to blastocyst stage was significantly different between transfected fetal fibroblast and both recloned treatment groups. Differences were observed in pregnancy rates between blastocysts generated by the different sources of donor cells. In spite of the lower blastocyst production, our results suggest that recloning provides an additional method to obtain transgenic animals, and that fibroblasts from umbilical cord could give better results for recloning than those obtained from young calf ear.

Effect of different sources of donor cells for calf recloning on embryo and fetal survival
79RELATIONSHIPS BETWEEN SURVIVAL RATE AND BIRTH WEIGHT IN CLONED KOREAN
NATIVE CALVES
Authors: Yang B.C. , Im G.S. , Kim D.H. , Lee S.K. , Park H.S. , Seong H.H. , Jung J.K. , Chang W.K. , Kim K.N.
Published: February 2004

Cloning of somatic cells has been investigated actively in cattle, but the cloned calves have been characterized by high birth weight and low survival rate. The present study was conducted to investigate the relationships between survival rate and birth weight in cloned and AI calves. The ear skin fibroblasts were obtained from 2- to 3-year-old Korean native cows (Hanwoo) and the cells were cultured in Dulbeccos Modified Eagles medium (DMEM) supplemented with 10% fetal bovine serum (FBS) at 38.5°C, 5% CO2 in air. Bovine oocytes collected from ovaries obtained from a nearby slaughterhouse were cultured in vitro and then enucleated, injected with donor cells and fused, and cultured to produce cloned embryos at the blastocyst stage. Somatic cell cloning and in vitro culture of embryos were performed by the procedures described previously (Im et al., 2001 AJAS 14, 759–764, and Im et al., 2001 AJAS 14, 1260–1266). A total of 580 cloned embryos at blastocyst stage were transferred to 293 recipient cows; 32 female calves (5.5%) were born (2 of them were born dead). Thirty-four (15 female and 19 male ) calves (57.6%) were born from 59 artificially inseminated Korean native cows as control. Fifteen of the 32 cloned calves were delivered by caesarean section. However, all the artificially inseminated cows delivered naturally. Birth weights of 30 live cloned calves averaged 31.08kg (>15kg:3, 20kg:2, 25kg:2, 30kg:5, 35kg:9, 40kg:6, <45kg:3), while those of female AI calves averaged 23.67kg (>15kg:0, 20kg:3, 25kg:6, 30kg:6, 35kg:0, 40kg:0, <45kg:0). After calving, 11 of 30 cloned calves survived for more than 365 days (birth weight of these calves averaged 28.25kg), but 19 of 30 calves died within 175 days and their average birth weight was 32.80kg (650kg). Gestation length of cows that received cloned embryos was 287 (279–295) days on average (excluding the data of calves delivered by caesarean section) and that of cows artificially inseminated was 287 (255–293) days. In conclusion, the birth weight was significantly correlated (P<0.05) with survival rate of cloned calves, and survival rates of calves with extremely high or low birth weights were significantly low. However, there was no relationship between gestation length and survival rate.
82COMPARISON OF THE SURVIVAL OF IN VITRO-DERIVED PORCINE OOCYTES AND
EMBRYOS VITRIFIED BY OPEN PULLED STRAW, ELECTRON MICROSCOPE GRID, AND NYLON
LOOP SYSTEM
Authors: Ahn M.-H. , Seok H.-B , Kim I.-D. , Son D.-S
Published: February 2004

Various sample containers have been developed for ultra-rapid vitrification of oocytes and embryos to minimize chilling and other injuries. In this study, the survival rates of in vitro-derived porcine oocytes were compared after cryopreservation using open pulled straw (OPS), electron microscope grid (EMG), and nylon loop system (NLS). In addition, the
post-thaw survival of porcine morulae and blastocysts was assessed after vitrification by the OPS method. In vitro maturation and fertilization were performed according to the procedures of Funahashi et al., 1994 Theriogenology 41, 1425–1433). Fertilized oocytes were cultured in glucose-free NCSU 23
supplemented with 5mM sodium pyruvate, 0.5mM sodium lactate and 4mgmL−1 bovine serum albumin for 2 days at 39°C; 10% fetal bovine serum was added to the culture medium thereafter. Oocytes and embryos were treated with 7.5μgmL−1 cytochalasin B for 30min, centrifuged at 13,000g for 13min and then exposed sequentially to an ethylene glycol (EG) vitrification solution (0M for 1min, 2M for 5min and 8M plus 7% polyvinylpyrrolidone for 1min).
Oocytes (n=100per treatment group) were placed in or on sample containers and plunged into liquid nitrogen. Porcine morulae and blastocysts (n=137) were similarly treated, aspirated into OPSs, and plunged into liquid nitrogen. Oocytes and embryos were thawed rapidly by transferring the sample container into 1M EG for 2min, and then the embryos were serially diluted by transfer into 0.5M for 2min, and medium for 5min. Post-thaw survival of vitrified oocytes was assessed by development after IVF and culture to morulae or blastocysts. Post-thaw survival of vitrified morulae and blastocysts was assessed by their ability to continue development to, respectively, blastocysts and expanded blastocysts. After oocytes were thawed, fertilized and cultured in vitro, the rates of development to the morula- or blastocyst-stage were 8%, 0% and 6% for, respectively, the OPS, EMG and NLS groups. The rate of development of non-cryopreserved control oocytes was 38% (38/100). Although significantly fewer oocytes developed after vitrification compared to the control (P<0.05), OPS and NLS containers were superior to EMG containers (P<0.05). Morula- or blastocyst-stage embryos vitrified using OPS yielded a significantly higher rate of survival than did oocytes (48%, 66/137; P<0.05). This study indicates that very few in vitro-matured porcine oocytes survive vitrification using OPS, EMG and NLS methods. Considerably higher rates of survival were obtained by in vitro-produced porcine morulae and blastocysts following vitrification by the OPS method. Additional research is needed to identify and develop methods to overcome the factors limiting the cryopreservation of porcine oocytes for practical uses. Supported by KOSEF (R05-2002-000-00388-0) grant.
84METHANOL AS A CRYOPROTECTANT FOR EQUINE EMBRYOS
Authors: Bass L.D. , Denniston D.J. , Maclellan L.J. , McCue P.M. , Squires E.L.
Published: February 2004

Equine embryos with diameters >300μm have low survival rates post-thaw, possibly due to low permeability of the cryoprotectant glycerol. Methanol has been used successfully for freezing ovine and murine embryos. The objectives of this study were: (1) examine the effect of methanol as a cryoprotectant for large equine embryos; (2) determine the diameter change of embryos exposed to methanol compared to glycerol; and (3) compare pregnancy rates of embryos cultured in vitro prior to transfer. Equine embryos (n=43) were recovered nonsurgically 7 to 8 days after ovulation and randomly assigned to be cryopreserved in one of two cryoprotectants: 4.8% v/v methanol (n=22) or 10% v/v glycerol (n=21). Embryos (300μm to 1000μm) were measured at 5 time points after exposure to glycerol (0, 2, 5, 10, and 15min) or methanol (0, 1.5, 3.5, 7.5 and 10min) to determine changes in diameter over time (%±SD). Embryos were loaded into 0.25-mL plastic straws, sealed, placed in a programmable cell freezer and cooled from room temperature (22°C) to −6°C. Straws were then seeded, held at −6°C for 10min, and cooled at 0.3°C/min to −30°C and then at 0.1°C/min to −33°C before being plunged into liquid nitrogen. Sets of three straws within a treatment group were thawed in air for 10s and then immersed in a 38°C water bath for 20s. Each set of three embryos was further assigned to be either cultured for 12h prior to transfer or transferred nonsurgically to a single mare immediately. Embryo diameter decreased in all embryos upon initial exposure to cryoprotectant. Embryos in methanol shrank and then recovered slightly to 76±8% of their original diameter; however, embryos in glycerol continued to shrink, reaching 57±6% of their original diameter prior to cryopreservation. Survival rates of embryos through Day 16 of pregnancy were 38% and 23%, respectively, P>0.05) for embryos cryopreserved in the presence of glycerol or methanol. There was no difference in pregnancy rates of mares receiving embryos that were cultured prior to transfer or not cultured (P>0.05). Methanol provided no advantage over glycerol as a cryoprotectant for equine blastocysts. Neither cryoprotectant provided satisfactory pregnancy rates of frozen/thawed large equine embryos. Further studies are needed to develop procedures for freezing large equine embryos.
88ESTABLISHMENT OF PREGNANCIES AFTER VITRIFICATION OF EQUINE EMBRYOS
Authors: Caracciolo di Brienza V. , Squires E.L. , Carnevale E.M.
Published: February 2004

Vitrification of equine embryos has been limited, with only one study reporting transfer of vitrified embryos into recipients (1994 Theriogenology 42, 483–488). The objective of this study was to vitrify equine embryos in different stages of development based on a protocol that had been successful in sheep (Naitanas et al., 1996 Theriogenology 46, 813–824) and buffalo (2001 Theriogenology 55, 307). Embryos, Days 6.5 to 7.5, were assigned to a 3 (stage)×2 (media) factorial design (n=3 per group) based on diameter and developmental stage [(1) morulae+very early blastocysts; (2) blastocysts <300μm; (3) blastocysts >300μm] and base media [(1) PBS supplemented with 0.3mM pyruvate, 3.3mM glucose and 10% FCS or (2) HCDM (Olson SE and Seidel GE Jr. 2000 J. Anim. Sci. 78, 152–157) with Eagle’s essential and nonessential amino acids, 2mM glucose, 3mgmL−1 BSA and 20% FCS]. Embryos were placed sequentially in 200μL of 1.4M glycerol for 5min, 200μL of 1.4M glycerol+3.6M ethylene glycol for 5min, and 30μL of 3.4M glycerol+4.6 M ethylene glycol. Within 30s, the 30-μL drop containing the embryo was loaded into the center of a 0.25-mL straw separated by air from columns (30μL) of the same solution. Straw ends were loaded with columns (60μL) of 0.5M galactose in base medium. The straw was heat-sealed and exposed to liquid-nitrogen vapor for 1min before being plunged into liquid nitrogen. To warm embryos, straws were held in air for 10s and then immersed in 20°C water for 10s. Embryos were transferred into 200μL of 0.25M galactose solution for 5min, and then placed in PBS or HCDM. Within 10min, embryos (n=3 per recipient), grouped for stage and media, were transferred nonsurgically into the uteri of 6 recipients that had ovulated 6 days earlier. Ultrasound exams were done at 4, 6, 8 and 10 days after transfer. Three morulae or very early blastocysts and one blastocyst <300μm, all vitrified in PBS, formed embryonic vesicles. Two of 3 vesicles, in the same recipient, were manually removed on Day 16. The remaining vesicle and the single vesicle, from a blastocyst <300μm, had normal development until Day 38 when pregnancies were terminated. No pregnancies were observed on Day 16 after use of HCDM. Because numbers of embryos were low, it is not clear if HCDM had a detrimental effect (P>0.1). Embryos were transferred in October, at the end of the breeding season. Therefore, quality of available recipients could have affected pregnancy rates. No pregnancies were observed from expanded blastocysts. Potentially, the embryonic capsule, present at this stage, impeded diffusion of cryoprotectants. These preliminary results demonstrate the potential for vitrification of small equine embryos.
91IMPACT OF PROPYLENE GLYCOL V. ETHYLENE GLYCOL ON OOCYTE
MATURATION, SPINDLE INTEGRITY, FERTILIZATION AND EMBRYO DEVELOPMENT IN VITRO
IN THE DOMESTIC CAT
Authors: Comizzoli P. , Wildt D.E. , Pukazhenthi B.S.
Published: February 2004

A thorough characterization of cryoprotectant (CPA) sensitivity is required to formulate a successful cryopreservation protocol for any biomaterial. The aim of this study was to characterize the toxic impact of various CPA types, concentrations, and exposure temperatures on the immature domestic cat oocyte. In Experiment 1, grade I immature oocytes (n=561) were exposed (30min; 25°C or 0°C) to 0M, 0.75M, 1.5M, or 3M of propylene glycol (PrOH) or ethylene glycol (EG) in PBS+20% fetal calf serum (v/v). After exposure, CPA was removed step-wise by subjecting oocytes to decreased CPA concentrations. Oocytes were cultured (30h; 38.5°C, 5% CO2) in IVM medium as reported previously (Wolfe and Wildt 1996 J. Reprod. Fertil. 106, 135–141). Oocytes were then fixed and stained to examine nuclear status (Hoechst 33342) and spindle integrity (FITC-labeled anti-α-tubulin antibodies; Sigma Chemical Co., St. Louis, MO). Experiment 2 was designed on the basis of Experiment 1 results to assess the impact of the spindle abnormalities on subsequent embryo development. Oocytes (n=776) were exposed to CPA conditions yielding optimal nuclear maturation with either high (0.75M or 3.0M PrOH or 1.5M EG at 25°C) or low (1.5M PrOH at 25°C) proportions of abnormal spindle. After IVM, oocytes were inseminated with thawed semen (5×105 motile sperm mL−1 ) in Ham’s F-10 (Irvine Scientific, St-Anna, CA). At 16h post-insemination, oocytes were fixed and stained (Hoechst 33342) to assess IVF success (pronuclear formation) or cultured in vitro for 7 days to assess embryo development. Data were analyzed by ANOVA and Tukey’s multiple comparison test. In Experiment 1, CPA treatment had no effect (NS) on meiotic progression to metaphase I. However, percentage of oocytes reaching metaphase II (MII) was reduced (P<0.05) in 3.0M PrOH at 0°C (29.3±8.3%; mean±SD), 3.0M EG at 25°C (33.7±8.9%), and 0°C (29.4±11.0%) compared to all other conditions examined (range, 52.0% to 62.0%). All CPA treatments also increased (P<0.05) spindle abnormalities at MII (range, 40.3% to 75.9%) compared to control (13.8±8.6%), except 1.5M PrOH at 25°C (20.7±10.1%). None of the CPA treatments in Experiment 2 influenced IVF success (range, 55% to 63%; NS). However, percentage of cleaved embryos was reduced (P<0.05) in 0.75M PrOH (32.1±4.1%), 1.5M EG (33.4±4.0%), and 3.0M PrOH (29.3±3.8%) compared to control (50.1±4.0%) or 1.5M PrOH (50.6±4.9%). Developmental competence (number of blastocysts relative to number of cleaved embryos) also was impaired (P<0.05) in 1.5M EG (16.5±7.4%) and 3.0M PrOH (14.9±7.8%) compared to the other conditions (range, 32.5% to 38.5%), including 1.5 PrOH at 25°C (32.5±7.8%). In conclusion, exposure of immature oocytes to 1.5M PrOH at 25°C does not adversely impact oocyte maturation, MII spindle, fertilization, or embryo development in vitro in the domestic cat.
MCALIGN: Stochastic Alignment of Noncoding DNA Sequences Based on an Evolutionary Model of Sequence Evolution
Authors: Keightley Peter D. , Johnson Toby
Published: March 2004

A method is described for performing global alignment of noncoding DNA sequences based on an evolutionary model parameterized by the frequency distribution of lengths of insertion/deletion events (indels) and their rate relative to nucleotide substitutions. A stochastic hill-climbing algorithm is used to search for the most probable alignment between a pair of sequences or three sequences of known phylogenetic relationship. The performance of the procedure, parameterized according to the empirical distribution of indel lengths in noncoding DNA of Drosophila species, is investigated by simulation. We show that there is excellent agreement between true and estimated alignments over a wide range of sequence divergences, and that the method outperforms other available alignment methods.
Exploring the micro‐ and nanoworld with cubic centimetre‐sized autonomous microrobots
Authors: Estaña R. , Seyfried J. , Schmoeckel F. , Thiel M. , Buerkle A. , Woern H.
Published: February 2004

In order to bridge the increasing gap between the micro‐ and nanotechnologies, a European consortium is currently developing and investigating a cluster of mobile, wireless cubic centimetre‐sized microrobots. The control and sensor issues which are to be solved for such a robot system are demanding. This paper describes the work carried out by one of the project partners. An interferometrical principle employing the so‐called “mechanical” interferometer based on the Moiré‐effect is used for the position sensor system. Further sensor systems involve “local” microscope cameras, for which the extraction of depth information is crucial.
The user interface system for the Robovolc exploration robot
Authors: Sim Patrick , Sacco Vincenzo , Singh Virk Gurvinder
Published: February 2004

This paper presents the development of the user interface for the Robovolc volcano exploration robot. The discussion examines the important issues, concepts that need to be considered and the lessons learnt during the overall development phase. The process by which the final user interface was developed is also described, examining the key stages and decisions that were made. Lastly, results of the final tests carried out on Mount Etna are also discussed.
The role of emotional intelligence and personality variables on attitudes toward organisational change
Authors: Vakola Maria , Tsaousis Ioannis , Nikolaou Ioannis
Published: February 2004

Although the role of organisational characteristics in the change process has been extensively analysed and discussed in the literature, individual characteristics, which are equally crucial for the success of change, have been neglected. Therefore, the purpose of the present study is to add a different way of looking and working with organisational change by focusing on individuals’ emotions and personality traits. This paper explores how emotional intelligence and the “big five” dimensions of personality can facilitate organisational change at an individual level by exploring the relationship between these attributes and attitudes toward organisational change. The sample consisted of 137 professionals who completed self‐report inventories assessing emotional intelligence, personality traits and attitudes towards organisational change. The results confirmed that there is a relationship between personality traits and employees’ attitudes toward change. Similarly, the contribution of emotional intelligence to the attitudes to change was found to be significant, indicating the added value of using an emotional intelligence measure above and beyond the effect of personality. The practical implications of these findings are discussed in relation to the phases of a change project.
Diffusion process models and strategic performance theory for new B2B electronic ventures
Authors: Woodside Arch , Gupta Samir , Cadeaux Jack
Published: February 2004

The Internet and its commercial applications in electronic commerce, particularly new ventures like B2B e‐markets, are experiencing a volatile introduction to the business environment. Businesses are restructuring and forming networks in an effort to accommodate and use this new phenomenon to their advantage. From this perspective, this article offers a conceptual framework on the process of creating these new ventures, the impact of network champions in the creation process and the strategic significance of the competency‐destroying innovation (Internet) for buyers and sellers who join the B2B e‐market. Several working propositions are developed from the extant literature that should be useful for empirical work on how new B2B e‐markets are implemented. The paper presents a refined proposition based on a field study of a B2B e‐market case.
Understanding sales quotas: an exploratory investigation of consequences of failure
Authors: Schwepker Charles H. , Good David J.
Published: February 2004

Sales quotas typically “drive” sales organizations. As such, the ability of the sales organization, both individually (the salesperson) and the group (the total collection of the sales professionals), to accomplish its quota has a significant impact on the performance of the sales and marketing organization, as well as the entire firm. Within the context of this use, quotas represent a critical sales goal, although very little is actually known about their strategic or operational use within marketing organizations. The purpose of this paper is to investigate quotas from a strategic and operational perspective to provide additional insight into understanding sales quotas. Specifically, this manuscript investigates the consequences of failing to achieve quota and the relationship between these consequences and salesperson performance, salesperson income, and the firm’s annual sales revenue. In addition, the relationship between these variables and quota difficulty, and quota performance are explored.
Accuracy of the Justy II Apex locator in determining working length in simulated horizontal and vertical fractures
Authors: Azabal M. , Garcia‐Otero D. , De La Macorra J. C.
Published: March 2004

Aim  To study the effectiveness of an electronic apex locator (EAL; Justy II; Yoshida Dentcraft, Tokyo, Japan) in locating simulated horizontal and vertical fractures in single roots.

Methodology  An EAL was used to measure the distance within the canal of horizontal (n = 31) and vertical (n = 31) fractures, created with a disk in single‐rooted teeth. Accuracy of the EAL was evaluated by comparing the measurements with those made using a size 10 file. Data were analysed with the non‐parametric Passing and Bablok method.

Results  For simulated horizontal fractures, the EAL measured exactly the same length as a size 10 file, without constant or proportional errors. In vertical simulated fractures, the EAL measured (on average) with a constant error of 7.5 mm shorter than the size 10 file; the difference had a wide confidence interval (−72.3 to 2.6 mm).

Conclusions  In this laboratory study, the Justy II EAL was able to determine accurately the position of simulated horizontal fractures, but was unreliable when measuring simulated vertical fractures.
Quantification of Restoration Success Using Complex Systems Concepts and Models
Authors: Anand Madhur , Desrochers Rachelle E.
Published: February 2004

Concepts and models from complex systems theory are introduced to help expand the approaches to quantify restoration success in ecology. Main points are illustrated using case studies. These include (1) recovery and restoration trajectories may be complex (nonlinear, unpredictable, and leading to multiple attractors), and thus knowledge of well‐known model trajectories from complex systems theory may be useful; (2) modeling may be inevitable, as complete and long‐term observation of recovery pathways are rarely possible; (3) holistic views (e.g., community level as opposed to population‐level) may be necessary to understand governing processes in restoration and recovery.
Ecosystem Level Impacts of Invasive Acacia saligna in the South African Fynbos
Authors: Yelenik S. G. , Stock W. D. , Richardson D. M.
Published: February 2004

Recent efforts to clear invasive plants from the fynbos of South Africa forces managers to think about how N2‐fixing invasives have altered ecosystem processes and the implications of these changes for community development. This study investigated the changes in nitrogen (N) cycling regimes in fynbos with the invasion of Acacia saligna, the effects of clear‐cutting acacia stands on soil microclimate and N cycling, and how altered N resources affected the growth of a weedy grass species. Litterfall, litter quality, soil nutrient pools, and ion exchange resin (IER)‐available soil N were measured in uninvaded fynbos, intact acacia, and cleared acacia stands. In addition, a bioassay experiment was used to ascertain whether the changes in soil nutrient availability associated with acacia would enhance the success of a weedy grass species. Acacia plots had greater amounts of litterfall, which had higher concentrations of N. This led to larger quantities of organic matter, total N, and IER‐available N in the soil. Clearing acacia stands caused changes in soil moisture and temperature, but did not result in differences in IER‐available N. The alteration of N availability by acacias was shown to increase growth rates of the weedy grass Ehrharta calycina, suggesting that secondary invasions by nitrophilous weedy species may occur after clearing N2‐fixing alien species in the fynbos. It is suggested that managers use controlled burns, the addition of mulch, and the addition of fynbos seed after clearing to lower the levels of available N in the soil and initiate the return of native vegetation.
Incidence of and socio‐demographic risk factors for stillbirth, preterm birth and low birthweight among Zimbabwean women
Authors: Feresu Shingairai A. , Harlow Siobán D. , Welch Kathy , Gillespie Brenda W.
Published: March 2004

Data on birth outcomes are important for planning maternal and child health care services in developing countries. Only a few studies have examined frequency of birth outcomes in Zimbabwe, none of which has jointly examined the spectrum of poor birth outcomes across important demographic subgroups. We assessed delivery patterns and birth outcomes in 17 174 births over a one‐year period from October 1997 to September 1998 at Harare Hospital, Zimbabwe. The annual rate of stillbirth was 61 per 1000 live births, rate of preterm birth (<37 weeks) was 168 per 1000, and low birthweight (LBW) (<2500 g) was 199 per 1000. Not attending antenatal care (prenatal care) was associated with increased risks of stillbirth [relative risk (RR) = 2.54, 95% CI 2.21, 2.92], preterm delivery [RR = 2.43, 95% CI 2.26, 2.61] and LBW births [RR = 2.16, 95% CI 2.02, 2.31]. Preterm births and LBW births were more likely to be stillborn [RR = 7.26, 95% CI 6.28, 8.39 and RR = 6.85, 95% CI 5.94, 7.91]. In conclusion, the rate of stillbirth is high and is predominantly associated with preterm births and to a lesser extent LBW. Reducing the frequency of stillbirth will require a better understanding of the determinants of preterm births and strategies for addressing this particular subset of high‐risk births.
A collection of 11 800 single‐copy Ds transposon insertion lines in Arabidopsis
Authors: Kuromori Takashi , Hirayama Takashi , Kiyosue Yuki , Takabe Hiroko , Mizukado Saho , Sakurai Tetsuya , Akiyama Kenji , Kamiya Asako , Ito Takuya , Shinozaki Kazuo
Published: March 2004

More than 10 000 transposon‐tagged lines were constructed by using the Activator (Ac)/Dissociation (Ds) system in order to collect insertional mutants as a useful resource for functional genomics of Arabidopsis. The flanking sequences of the Ds element in the 11 800 independent lines were determined by high‐throughput analysis using a semi‐automated method. The sequence data allowed us to map the unique insertion site on the Arabidopsis genome in each line. The Ds element of 7566 lines is inserted in or close to coding regions, potentially affecting the function of 5031 of 25 000 Arabidopsis genes. Half of the lines have Ds insertions on chromosome 1 (Chr. 1), in which donor lines have a donor site. In the other half, the Ds insertions are distributed throughout the other four chromosomes. The intrachromosomal distribution of Ds insertions varies with the donor lines. We found that there are hot spots for Ds transposition near the ends of every chromosome, and we found some statistical preference for Ds insertion targets at the nucleotide level. On the basis of systematic analysis of the Ds insertion sites in the 11 800 lines, we propose the use of Ds‐tagged lines with a single insertion in annotated genes for systematic analysis of phenotypes (phenome analysis) in functional genomics. We have opened a searchable database of the insertion‐site sequences and mutated genes (http://rarge.gsc.riken.go.jp/) and are depositing these lines in the RIKEN BioResource Center as available resources (http://www.brc.riken.go.jp/Eng/).
Resuscitation beyond 10 minutes of term babies born without signs of life
Authors: Patel H , Beeby PJ
Published: February 2004

Objective:  To obtain population‐based data on babies who were admitted to a neonatal intensive care unit despite having Apgar scores of 0 up to and including 10 min, and to document their outcomes. We aimed also to review other studies where outcomes following a 10‐min Apgar score of 0 were described, and to combine them with own results. Current recommendations regarding the discontinuation of resuscitation will be reconsidered in light of these results.

Methods:  In order to obtain population‐based data for babies born in New South Wales (NSW), a request was made to the NSW Neonatal Intensive Care Unit Study (NICUS) directors to allow identification of babies in the NICUS database with Apgar scores of 0 at both 1 and 5 minutes. Individual directors were then asked to determine from their hospital records, which of these babies had a 10‐minute Apgar of 0, and to provide the results of follow‐up assessments of any survivors in this subgroup

Results:  Twenty‐nine full‐term newborns with a 10‐minute Apgar score of 0 were identified. Twenty of the 29 babies died before leaving hospital. Of the 9 who were discharged alive, eight had severe disability and one had moderate disability. Thus death or severe disability occurred in 28/29 (97%), and death or any disability in 100%. Combining with other published studies, death or severe disability occurred in 63/64 (98%).

Conclusion:  The above findings strongly support the discontinuation of resuscitation if a baby remains asystolic at 10 minutes.
Infrequent Shocks, Output Persistence and Economic Growth
Authors: Caruso Massimo
Published: February 2004

The robustness of the relationship between the persistence of output fluctuations and trend growth is evaluated. The analysis introduces discontinuities in output processes and examines the role of convergence across countries. Breaking trends influence the world distribution of permanent shocks and evidence is presented on persistent differences in output patterns associated with both the catching‐up process and technological progress. Overall, a positive correlation between output persistence and growth is confirmed. These results indicate that documenting and interpreting how the characteristics of the business cycle are related to long‐run growth is an important topic that deserves further attention in the profession.
A Cautionary Note on the Order of Integration of Post‐war Aggregate Wage, Price and Productivity Measures
Authors: Sollis Robert , Wohar Mark E.
Published: February 2004

We investigate the order of integration of aggregate wage, price and productivity measures for the USA. Our investigation differs from previous studies as we employ recently developed tests that allow, under the alternative hypothesis, for structural change between periods in which the data are integrated of order zero, I(0), and integrated of order one, I(1). The tests reveal that some of the time series examined are neither exclusively I(0) or I(1) and that in fact breaks in the order of integration have occurred, suggesting the need for caution when undertaking Granger‐causality tests involving these variables.
The Empirical Spectator and Gallery Education
Authors: Fulkova Marie , Straker Alison , Jaros Milan
Published: February 2004

This paper examines the onto‐epistemic status and understanding of contemporary material culture and of visual art, particularly in the context of gallery education. It does so through a case study of the response of 15 year‐old school students in the Czech Republic and in England to a recent photographic exhibition, I.N.R.I., created by artists Bettina Rheims and Serge Bramly. It supports and develops further the proposition that the tradition grounded in the concept of a single ‘objective’ interpretation of a work of art has been significantly undermined by the paradigmatic change that has taken place in the last decades. In the course of this process the vocabulary of signification (e.g. doves, the royal blue, temptations of Christ, class struggle) inherited from the age of ideologies and grand narratives has been significantly weakened. In its place there emerged the vocabulary of signs born out of the language of high tech media. It takes the form of dynamically constituted units identifiable via daily exposure to techno processes, e.g. familiar from advertising and networking, at best mere fragments of traditional narratives. The recognition of reality is couched in terms of consumer units originating in objects (e.g. gadgetry) and object‐based practices filling (indeed constituting) the living place of today. This shift is particularly apparent among English young people, brought up in a more consumer‐oriented society, and to a lesser degree among Czechs. This is well in keeping with the concept of the post‐modern ‘empirical spectator’ developed in recent literature on art and material culture education.
The Role of Art and Craft Collections in Teacher Training Institutions in Australia
Authors: Collet Penelope J.
Published: February 2004

In postwar Australia, rapid population growth increased the demand for teachers. The colleges at Ballarat and Bendigo were revived and expanded by the Victorian Government. At Bendigo in 1955 F. M. Courtis, Head of Art Education, acquired art works initiating a valuable and significant teaching resource at the College. The study of the Courtis Collection raised obvious questions about the role of collections in the early teaching colleges and what events or factors led to their beginnings. This case study will be situated within a broader picture of art and craft collections in institutions across three states. My discussions in this paper are framed by some of Raymond Williams' notions about country and city and the ‘contrast between country and city, as fundamental ways of life’. I hope to demonstrate the important role art and craft collections have played in visual arts education in country institutions.
“Solvering” the Physical Pendulum
Authors: Hart Francis X.
Published: February 2004

In this paper I describe an experiment in which the maximum speed and damping of a physical pendulum are measured as the position of its center of mass is varied. The measured speeds are fit to an exponential decay model using the Solver function of Excel. Energy conservation provides calculated values for the dependence of velocity on center-of- mass (c.m.) position.
Estimating the Speed of Light from a Satellite Echo
Authors: Keeports David
Published: February 2004

A few years ago I heard a clear and consistent telephone echo during a series of phone calls to Russia. I will explain in this paper how, by making a few assumptions about the source of the echo and by applying some introductory-level physics, I was able to obtain a rough lower limit for the speed of light.
User-Defined Scroll Bars in Spreadsheets
Authors: Hatten Daniel L. , Moloney Michael J.
Published: February 2004

Microsoft Excel allows the easy creation of user-defined scroll bars that can be used to control parameter values in a spreadsheet. These scroll bars make it convenient to use a spreadsheet for in-class demonstrations, animations, and curve fitting, and offer significant instructional value to the student.
Microvascular pressure and functional capillary density in extreme hemodilution with low- and high-viscosity dextran and a low-viscosity Hb-based O2 carrier
Authors: Cabrales Pedro , Tsai Amy G. , Intaglietta Marcos
Published: February 2004

Blood losses are usually corrected initially by the restitution of volume with plasma expanders and subsequently by the restoration of oxygen-carrying capacity using either a blood transfusion or possibly, in the near future, oxygen-carrying plasma expanders. The present study was carried out to test the hypothesis that high-plasma viscosity hemodilution maintains perfused functional capillary density (FCD) by preserving capillary pressure. Microvascular pressure responses to extreme hemodilution with low- (LV) and high-viscosity (HV) plasma expanders and an exchange transfusion with a polymerized bovine cell-free Hb (PBH) solution were analyzed in the awake hamster window chamber model ( n = 26). Systemic hematocrit was reduced from 50% to 11%. PBH produced a greater mean arterial blood pressure than the nonoxygen carriers. FCD was higher after a HV plasma expander (70 ± 15%) vs. PBH (47 ± 12%). Microvascular pressure spanning the capillary network was higher after a HV plasma expander (16–19 mmHg) compared with PBH (12–16 mmHg) and a LV plasma expander (11–14 mmHg) but lower than control (22–26 mmHg). FCD was found to be directly proportional to capillary pressure. The use of a HV plasma expander in extreme hemodilution maintained the number of perfused capillaries and tissue perfusion by comparison with a LV plasma expander due to increased mean arterial blood pressure and capillary pressure. The use of PBH increased mean arterial pressure but reduced capillary pressure due to vasoconstriction and did not maintain FCD.
Puberty: A Finishing School for Male Social Behavior
Authors: SISK CHERYL L. , SCHULZ KALYNN M. , ZEHR JULIA L.
Published: March 2004

Abstract: The classical view of steroid‐dependent organization of brain and behavior holds that gonadal steroid hormones, acting during an early critical period of development, cause permanent structural changes in neural circuits that determine behavioral responses to hormones in adulthood. This classical view has been modified to incorporate evidence that organizational effects of steroids can occur outside of the established perinatal critical period and that multiple critical periods may exist during development. Experiments in this laboratory indicate that steroid‐dependent organization of neural circuits underlying male social behaviors occurs during puberty. This work shows that adult‐typical reproductive and flank marking behaviors cannot be activated by gonadal steroids in male Syrian hamsters prior to puberty, suggesting that developmentally timed processes during puberty render the nervous system responsive to activating effects of gonadal steroids in adulthood. Additional experiments demonstrate that the presence or absence of gonadal hormones during puberty is a major factor in the ability of steroids to activate reproductive and flank marking behavior in adult male hamsters and in androgen receptor expression within the neural circuit underlying these behaviors. Thus, gonadal hormones during puberty appear to exert long‐lasting changes in neural circuits that are responsible for the programming of activational responses to steroids later in adulthood. A two‐stage model for maturation of male social behaviors is proposed: a perinatal critical period for sexual differentiation of neural circuits, followed by the pubertal period, during which gonadal steroids further organize the circuits to enhance behavioral responsiveness to hormones in adulthood. Whether puberty is a critical period for the proposed second wave of steroid‐dependent organization of behavioral circuits remains to be determined.
Aromatase (Estrogen Synthase) Activity in the Dorsal Horn of the Spinal Cord: Functional Implications
Authors: EVRARD HENRY C. , BALTHAZART JACQUES
Published: March 2004

Abstract: The presence of aromatase (estrogen synthase) in neurons in the dorsal horn of the spinal cord in Japanese quail suggests that estrogens produced locally from androgens could control spinal sensory processes including nociception. We used the hot water nociceptive test (54°C) to appraise the long‐term effect of an inhibition of aromatization on the foot withdrawal latency in male quail. Four weeks after the ablation of their main source of testosterone (testes), castrated males displayed a significantly higher foot withdrawal latency than gonadally intact males. A prolonged treatment with subcutaneous capsules filled with testosterone or 17 beta‐estradiol restored the baseline latency within 2 weeks. The effect of testosterone in castrated quail was almost completely blocked by systemic injections of Vorozole™, a nonsteroidal aromatase inhibitor or tamoxifen, an estrogen receptor antagonist (one injection per day for 10 days). Taken together, these data demonstrate for the first time to our knowledge an effect of estrogens formed by aromatization of androgens on nociception. Because aromatase‐immunoreactive neurons and aromatase activity are present in the dorsal horns of the spinal cord, this control of pain thresholds is presumably mediated, at least in part, by estrogens produced at the spinal level that act locally via slow, presumably genomic, mechanisms mediated by the activation of spinal nuclear estrogen receptors.
Neurogenesis in the Subependymal Layer of the Adult Rat
Authors: GIACHINO CLAUDIO , GALBIATI MARIARITA , FASOLO ALDO , PERETTO PAOLO , MELCANGI ROBERTO
Published: March 2004

Abstract: The subependymal layer (SEL) of the adult mammalian brain provides a continuous supply of newborn cells that migrate to the olfactory bulb (OB) where they differentiate into interneurons. These newly generated cells migrate tangentially to the OB within a dense meshwork of astrocytic cells, organized to form tangentially oriented channels (glial tubes). The central nervous system is able to synthesize a variety of steroids. Among these, we analyzed the effects of progesterone (P) and its neuroactive metabolites dihydroprogesterone (DHP) and tetrahydroprogesterone (THP), administered by intraventricular injection, on the SEL of the adult rat. We found that THP and DHP, but not their precursor P, modify glial tubes organization and decrease immunoreactivity for glial associated proteins in SEL astrocytes. Moreover P metabolites reduce the proliferative activity within the SEL.
Ndrg2, a Novel Gene Regulated by Adrenal Steroids and Antidepressants, Is Highly Expressed in Astrocytes
Authors: NICHOLS NANCY R.
Published: March 2004

Abstract: Previously, we cloned a gene from rat hippocampus that now shows homology to Ndrg2, a member of the N‐myc downregulated gene (NDRG) family with putative roles in neural differentiation, synapse formation, and axon survival. Following adrenalectomy, hippocampal Ndrg2 mRNA increased in response to glucocorticoids. Ndrg2 mRNA was also upregulated by corticosterone in cerebral cortex and heart. Since Ndrg2 mRNA increased in response to glucocorticoid treatment of cultured astrocytes, we examined its cellular localization in adult brain by in situ hybridization. Ndrg2 mRNA is a prevalent message that is widely expressed throughout the brain, but is more abundant in gray matter than in white matter. Predominant mRNA expression was found in neurogenic regions of the adult brain. Furthermore, Ndrg2 mRNA in these regions was localized to GFAP‐positive astrocytes or radial glia. In one of these regions, the subgranular zone of the dentate gyrus, Ndrg2 expression was decreased after adrenalectomy, and was restored to sham‐operated levels by corticosterone, indicating that it is under positive regulation by glucocorticoids in vivo. Recently, another group reported that Ndr2/Ndrg2 transcripts in rat frontal cortex were decreased by chronic antidepressant treatment. Because antidepressants may alleviate symptoms of depression by reversing the effects of glucocorticoids, these data suggest that further study of Ndrg2 regulation and function in glia could contribute to understanding the pathogenesis and treatment of depression.
Corticosteroid Receptor Transgenic Mice
Authors: URANI ALEXANDRE , GASS PETER
Published: March 2004

Abstract: Dysregulations and dysfunctions of corticosteroids and their receptors have been implicated in the pathogenesis of stress‐related disorders, in particular in depression. It is currently under debate, however, whether corticosteroid imbalances are a cause or rather a consequence of affective disorders. Corticosteroids exert their effects mainly by two receptors: glucocorticoid receptors (GRs) and mineralocorticoid receptors (MRs). We present here analyses made on several strains of mice with targeted mutations of corticosteroid receptors. The results help to understand how corticosteroid receptors regulate the hypothalamic‐pituitary‐adrenal (HPA) system. Furthermore, first behavioral analyses have indicated that corticosteroid receptor mutant mice show alterations in their emotional behavior. Certain mouse strains with specific alterations of GR or MR expression may represent genetic models of depression or at least have a predisposition to develop a depressive or a depression‐resistant state upon exposure to stress. The corticosteroid receptor‐regulated target genes to be identified in these models may code for proteins that could represent new drug‐targets for the treatment of affective disorders.
Selective Tail-to-Tail Dimerization of Ethyl Acrylate Catalyzed by Dirhodium Complexes
Authors: Kaneko Yuichi , Kanke Tsuyoshi , Kiyooka Syun-ichi , Isobe Kiyoshi
Published: March 2004

A catalytic selective tail-to-tail dimerization of ethyl acrylate was achieved by using dinuclear rhodium complexes, [(RhCp*)2(μ-CH2)2(CH3CN)2](BF4)2(Cp*=C5Me5) (1a) and [(RhCp*)2(μ-CH2)2(CO)2](BF4)2 (2). The corresponding dimethyl complex, [(RhCp*)2(μ-CH2)2(CH3)2] (3), showed catalytic ability only in the presence of HBF4·OEt2.
Ytterbium(II)-Aromatic Imine Dianion Complexes-Catalyzed Isomerization of Terminal Alkynes
Authors: Makioka Yoshikazu , Saiki Akira , Takaki Ken , Taniguchi Yuki , Kitamura Tsugio , Fujiwara Yuzo
Published: March 2004

Ytterbium-aromatic imine dianion complexes, easily prepared from ytterbium metal and aromatic imines, can act as effective catalysts for the isomerization of terminal alkynes to afford internal alkynes in good to high yields.