bluuebunny/crossref_metadata_2025_split huggingface dataset:
Frequency of recombinant and nonrecombinant products of pericentric inversion of chromosome 1 in sperm nuclei of carrier: By FISH technique
Authors: Yakut Tahsin , Acar Hasan , Egeli Ünal , Kimya Yalçin 
Published: July 2003

AbstractMeiotic segregation products of carriers with pericentric inversion are very important for assessing the risk of unbalanced forms and appropriate genetic counseling. We investigated the incidence of recombinant and nonrecombinant products of chromosome 1 with pericentric inversion, in the sperm nuclei of the carrier by using triple color fluorescence in situ hybridization (FISH). The centromere specific and telomere specific probes for chromosome 1 were used. In the segregation analysis, 1,636 sperm nuclei were analyzed; 82.5% of the sperms were including normal or inverted chromosome 1, and the dup(p)/del(q) and del(p)/dup(q) recombinant products in sperm nuclei of our carrier were 8.7 and 7.3%, respectively. The number of recombinant products may be dependent on the formation of an inversion loop, which the number of the formation of chiasmata results in the different number of normal/balanced and recombinant products. The use of FISH, using different probe combination, in sperm nuclei has proved to be an accurate approach to determine the meiotic segregation patterns and could help to better establish a reproductive prognosis and genetic counseling. Mol. Reprod. Dev. 66: 67–71, 2003. © 2003 Wiley‐Liss, Inc.
Glutamine and the maintenance of meiotic arrest in mouse oocytes: Influence of culture medium, glucose, and cumulus cells
Authors: Downs Stephen M. , Verhoeven Amelia 
Published: July 2003

AbstractThe selection of culture media and supplements therein has a tremendous impact on the regulation of oocyte maturation in vitro. In the present study, we have evaluated how altering the levels of glutamine in the presence or absence of glucose affects meiotic arrest in cumulus cell‐enclosed oocytes (CEO) and denuded oocytes (DO) when cultured in either the simple medium M16 or the more complex Eagle's minimum essential medium (MEM). We have also tested the effectiveness of follicle‐stimulating hormone (FSH) in triggering germinal vesicle breakdown (GVB) and purine de novo synthesis in differing MEM culture conditions. When DO were cultured 17–18 hr in hypoxanthine (HX)‐ or dbcAMP‐supplemented M16 medium, neither glucose nor glutamine had any effect on oocyte maturation, with dbcAMP the more effective inhibitor. In the absence of glutamine, cumulus cells promoted meiotic resumption, since significantly lower levels of meiotic arrest were maintained in CEO than in DO by either HX or dbcAMP, but addition of the amino acid dose‐dependently decreased the maturation percentage in CEO below that observed in DO. In MEM, glutamine and glucose again had little effect on the maturation of DO, although the percentage of maturing DO in HX‐supplemented medium was about 20% lower than that in M16 medium. In the absence of glucose, high levels of maturation were observed in CEO in glutamine‐free medium that were dose‐dependently lowered by the amino acid. However, when glucose was present, CEO were as effectively arrested as DO when glutamine was absent, with no further effect of the amino acid. This inhibitory action of glucose was dependent on the essential amino acids present in MEM. The effects of glutamine were not due to changes in metabolic coupling between the oocyte and cumulus cells. Measurement of purine de novo synthesis indicated that the maintenance of meiotic arrest as well as FSH induction of meiotic resumption were associated with increases in purine synthesis. We conclude that glucose and glutamine act cooperatively to promote the synthesis of new purine compounds within the somatic compartment and that the timing and duration of such synthesis determines whether meiotic resumption will be suppressed or promoted. Mol. Reprod. Dev. 66: 90–97, 2003. © 2003 Wiley‐Liss, Inc.
Cytochrome c oxidase of mammals contains a testes‐specific isoform of subunit VIb—the counterpart to testes‐specific cytochrome c?
Authors: Hüttemann Maik , Jaradat Saied , Grossman Lawrence I. 
Published: July 2003

AbstractSperm motility is highly dependent on aerobic energy metabolism, of which the apparent rate‐limiting step of the mitochondrial respiratory chain is catalyzed by cytochrome c oxidase (COX). COX is the only electron transport chain complex to display isoforms, consistent with its suggested rate‐limiting role. Isoforms were previously described for four of the 13 subunits. We now report the discovery that COX subunit VIb displays a testes‐specific isoform in human, bull, rat, and mouse (COX VIb‐2). Analysis of a variety of rat and mouse tissues, including ovaries, demonstrates exclusive expression of VIb‐2 in testes, whereas VIb‐1 transcripts are absent in rodent testes, even at early developmental stages. In contrast, both isoforms are transcribed in human testes. In situ hybridizations with human, rat, and mouse testes sections reveal VIb‐2 transcripts in all testicular cell types. Within the seminiferous tubules, VIb‐1 shows stronger signals in the periphery than in the lumen. Previously, cytochrome c was the only component of the mitochondrial respiratory chain known to express a testes‐specific isoform in mammals. COX subunit VIb connects the two COX monomers into the physiological dimeric form, and is the only COX subunit that, like cytochrome c, is solely located in the inter‐membrane space. Significant differences between the isoform sequences, in particular changes in charged amino acids, suggest interactions with cytochrome c and sperm‐specific energy requirements. Mol. Reprod. Dev. 66: 8–16, 2003. © 2003 Wiley‐Liss, Inc.
Improved developmental competence of cloned porcine embryos with different energy supplements and chemical activation
Authors: Lee Gab‐Sang , Kim Hye‐Soo , Hyun Sang‐Hwan , Kim Dae‐Young , Lee So‐Hyun , Nam Dong‐Hyun , Jeong Yeon‐Woo , Kim Sue , Kang Sung‐Keun , Lee Byeong‐Chun , Hwang Woo‐Suk 
Published: July 2003

AbstractThe present study investigated the effect of lactate/pyruvate supplement in culture medium and of chemical activation after electric stimulus on in vitro development of porcine somatic cell nuclear transfer (SCNT) embryos. In vitro matured gilt oocytes were enucleated, reconstructed with fetal fibroblasts, and simultaneously fused/activated using a single pulse of 2.0 kV/cm for 30 μsec. In Experiment 1, reconstructed embryos were cultured in North Carolina State University (NCSU)‐23 medium supplemented with either 5.5 mM glucose (Group A) or lactate (5.0 mM)/pyruvate (0.5 mM) (Group B). Compared to Group A, cleavage rate (64% vs. 47%) was higher and more blastocysts developed in Group B (17% vs. 6% at Day 6, 21% vs.11% at Day 7). Experiment 2, embryos reconstructed by electric stimulus (2.0 kV/cm for 30 μsec) were subjected to three activation protocols: (1) no chemical activation (Group C), (2) 7.5 μg/ml cytochalasin B treatment at 2 hr after electric stimulus (Group D), and (3) 5 μg/ml 6‐dimethylaminopurine (Group E) treatment at 2 hr after electric stimulus. The reconstructed embryos were cultured for 7 days in NCSU‐23 medium supplemented with lactate (5.0 mM)/pyruvate (0.5 mM). The rates of blastocyst formation on Day 6 and Day 7 in Group C (17 and 20%, respectively) or Group D (15, 20%, respectively) were higher than in Group E (9 and 12%, respectively). The percentage of two pseudo‐pronucleus (PPN) formations in Group D (88%) was significantly higher than in Group C (71%) and Group E (72%). Mean cell numbers of blastocysts in Group D (63.4 ± 15.8) were higher than in Group C (43.9 ± 16.5) and Group E (32.9 ± 17.9), due to increased trophectoderm (TE) cell numbers. Our results indicate that supplementing NCSU‐23 medium with lactate/pyruvate and exposure of cytochalasin B after electrical stimulus can improve in vitro developmental competence of porcine SCNT embryos. Mol. Reprod. Dev. 66: 17–23, 2003. © 2003 Wiley‐Liss, Inc.
Precise recapitulation of methylation change in early cloned embryos
Authors: Kang Yong‐Kook , Yeo Seungeun , Kim Seok‐Ho , Koo Deog‐Bon , Park Jung Sun , Wee Gabbine , Han Jee‐Soo , Oh Keon Bong , Lee Kyung‐Kwang , Han Yong‐Mahn 
Published: July 2003

AbstractChange of DNA methylation during preimplantation development is very dynamic, which brings this term to the most attractive experimental target for measuring the capability of cloned embryo to reprogram its somatic genome. However, one weak point is that the preimplantation stage carries little information on genomic sequences showing a site‐specific re‐methylation after global demethylation; these sequences, if any, may serve as an advanced subject to test how exactly the reprogramming/programming process is recapitulated in early cloned embryos. Here, we report a unique DNA methylation change occurring at bovine neuropeptide galanin gene sequence. The galanin gene sequence in early bovine embryos derived by in vitro fertilization (IVF) maintained a undermethylated status till the morula stage. By the blastocyst, certain CpG sites became methylated specifically, which may be an epigenetic sign for the galanin gene to start a differentiation programme. The same sequence was moderately methylated in somatic donor cell and, after transplanted into an enucleated oocyte by nuclear transfer (NT), came rapidly demethylated to a completion, and then, at the blastocyst stage, re‐methylated at exactly the same CpG sites, as observed so in normal blastocysts. The precise recapitulation of normal methylation reprogramming and programming at the galanin gene sequence in bovine cloned embryos gives a cue for the potential of cloned embryo to superintend the epigenetic states of foreign genome, even after global demethylation. Mol. Reprod. Dev. 66: 32–37, 2003. © 2003 Wiley‐Liss, Inc.
Expression of angiogenesis‐ and apoptosis‐related genes in chorionic villi derived from recurrent pregnancy loss patients
Authors: Choi Hee‐Kyung , Choi Bum Chae , Lee Sook‐Hwan , Kim Jeong Wook , Cha Kwang Yul , Baek Kwang‐Hyun 
Published: July 2003

AbstractAngiogenesis takes place during embryogenesis, characterized by the formation of new blood vessels from pre‐existing ones. This biological process is also found in the female reproductive system, wound healing, and cancer development. Apoptosis, programmed cell death, is a physiological process in development, tissue homeostasis, and disease. Apoptosis is a normal event in several reproductive tissues including human placenta. In these studies, we investigated whether aberrant angiogenesis and apoptosis are associated with recurrent pregnancy loss (RPL). We compared the gene expression level for angiogenesis‐ and apoptosis‐related genes in chorionic villi from RPL patients and those from normal controls. Semi‐quantitative reverse transcriptase‐polymerase chain reaction (RT‐PCR) analysis revealed that 7 angiogenesis‐ and 12 apoptosis‐related genes were abnormally expressed in chorionic villi from RPL patients. Angiogenesis‐related genes that showed aberrant expression level are matrix metalloproteinase‐2 (MMP‐2), plasminogen activator inhibitor (PAI), integrin, transforming growth factor‐β (TGF‐β), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and leptin receptor. Expression levels for these genes, except for leptin receptor, showed less in chorionic villi from RPL patients than those from normal controls. In contrast, higher expression levels of 12 apoptosis‐related genes (caspase 3, 6, 7, 8, 9, 10, 12, BAD, BAX, BID, Fas, and FasL) were shown in chorionic villi from RPL patients than those from normal controls. Taken all together, it is likely that the lower expression of angiogenesis‐related genes and the excessive expression of apoptosis‐related genes are associated with RPL. Mol. Reprod. Dev. 66: 24–31, 2003. © 2003 Wiley‐Liss, Inc.
Mouse ICSI with frozen–thawed sperm: The impact of sperm freezing procedure and sperm donor strain
Authors: Moreira Pedro N. , Jimenéz Adela , Fernández Raul , Bury‐Madrid Ninoska , De La Fuente Julio , Pintado Belen , Gutiérrez‐Adán Alfonso 
Published: July 2003

AbstractNormal mouse offspring can be obtained from oocytes injected with frozen–thawed spermatozoa without cryoprotection, however, embryo development can be affected by sperm freezing procedure and sperm donor strain. In this study we observed that direct contact of mouse spermatozoa with liquid nitrogen did not affect their ability to activate injected oocytes but severely restricted subsequent in vitro embryo development to blastocyst stage. Tris‐EDTA buffer and M2 were also shown to be better sperm freezing extenders than DPBS, allowing higher developmental potential. In addition, differences in embryo development obtained by intracytoplasmic sperm injection (ICSI) with frozen–thawed spermatozoa were observed between hybrid sperm donor strains. Frozen–thawed B6D2F1 spermatozoa provided higher embryo development than sperm cells from C57CBAF1. Mol. Reprod. Dev. 66: 98–103, 2003. © 2003 Wiley‐Liss, Inc.
Sensitivity curves for effective project management
Authors: Bowman R. Alan 
Published: July 2003

AbstractA key problem in project management is to decide which activities are the most important to manage and how best to manage them. A considerable amount of literature has been devoted to assigning “importance” measures to activities to help with this important task. When activity times are modeled as random variables, these activity importance measures are more complex and difficult to use. A key problem with all existing measures is that they summarize the importance in a single number. The result is that it is difficult for managers to determine a range of times for an activity that might be acceptable or unacceptable. In this paper, we develop sensitivity curves that display the most useful measures of project performance (in terms of schedule) as a function of an activity's time. The structure of the networks allows us to efficiently estimate these curves for all desired activities, all desired time ranges, and all desired measures in a single set of simulation runs. The resulting curves provide insights that are not available when considering summarized measures alone. Chief among these insights is the ability to identify an acceptable range of times for an activity that will not lead to negative scheduling consequences. © 2003 Wiley Periodicals, Inc. Naval Research Logistics 50: 481–497, 2003
The cost impact of using simple forecasting techniques in a supply chain
Authors: Kim Heung‐Kyu , Ryan Jennifer K. 
Published: July 2003

AbstractIn this paper we consider an inventory model in which the retailer does not know the exact distribution of demand and thus must use some observed demand data to forecast demand. We present an extension of the basic newsvendor model that allows us to quantify the value of the observed demand data and the impact of suboptimal forecasting on the expected costs at the retailer. We demonstrate the approach through an example in which the retailer employs a commonly used forecasting technique, exponential smoothing. The model is also used to quantify the value of information and information sharing for a decoupled supply chain in which both the retailer and the manufacturer must forecast demand. © 2003 Wiley Periodicals, Inc. Naval Research Logistics 50: 388–411, 2003
Discretization of the continuous ambush game
Authors: Woodward I.D. 
Published: July 2003

AbstractThis article further considers the two‐person continuous ambush game introduced by Ruckle. This article extends the work of Ruckle, Baston and Bostock, and Lee by considering the game for a general number of barriers. By supplanting optimal strategies from a discretized version of the game, we show that there always exists a value for the game, which, furthermore, can be found using linear programming techniques. Further to this, we show that the discrete ambush game considered by Garnaev has the same value as a continuous game, allowing many new results to be obtained in both games. © 2003 Wiley Periodicals, Inc. Naval Research Logistics 50: 515–529, 2003
Analysis of a machine repair problem with an unreliable server and phase type repairs and services
Authors: Chakravarthy Srinivas R. , Agarwal Atul 
Published: July 2003

AbstractIn this paper we study a machine repair problem in which a single unreliable server maintains N identical machines. The breakdown times of the machines are assumed to follow an exponential distribution. The server is subject to failure and the failure times are exponentially distributed. The repair times of the machine and the service times of the repairman are assumed to be of phase type. Using matrix‐analytic methods, we perform steady state analysis of this model. The time spent by a failed machine in service and the total time in the repair facility are shown to be of phase type. Several performance measures are evaluated. An optimization problem to determine the number of machines to be assigned to the server that will maximize the expected total profit per unit time is discussed. An illustrative numerical example is presented. © 2003 Wiley Periodicals, Inc. Naval Research Logistics 50: 462–480, 2003
Simultaneous production of market‐specific and global products: A two‐stage stochastic program with additional demand after recourse
Authors: Cattani Kyle , Ferrer Geraldo , Gilland Wendell 
Published: July 2003

AbstractThis paper analyzes the simultaneous production of market‐specific products tailored to the needs of individual regions and a global product that could be sold in many regions. We assume that the global product costs more to manufacture, but allows the decision concerning the allocation of products to regions to be delayed until after the manufacturing process has been completed. We further assume that there is additional demand after the region allocation but prior to delivery, extending the two‐stage stochastic program with recourse to include additional stochastic demand after the recourse. This scenario arises, for example, when there is additional uncertainty during a delivery delay which might occur with transoceanic shipments. We develop conditions for optimality assuming a single build‐allocate‐deliver cycle and stochastic demand during both the build and deliver periods. The optimal policy calls for the simultaneous production of market‐specific and global products, even when the global product is substantially more costly than the market‐specific product. In addition, we develop bounds on the performance of the optimal policy for the multicycle problem. © 2003 Wiley Periodicals, Inc. Naval Research Logistics 50: 438–461, 2003
Heuristic algorithms for routing yard‐side equipment for minimizing loading times in container terminals
Authors: Kim Ki Young , Kim Kap Hwan 
Published: July 2003

AbstractThis paper discusses a method of routing yard‐side equipment during loading operations in container terminals. Both the route of yard‐side equipment (such as transfer cranes or straddle carriers) and the number of containers picked up at each yard‐bay is determined simultaneously. The objective of the problem in this paper is to minimize the total container‐handling time in a yard. The size of the search space can be greatly reduced by utilizing inherent properties of the optimal solution. An encoding method is introduced to represent solutions in the search space. A genetic algorithm and a beam search algorithm are suggested to solve the above problem. Numerical experiments have been conducted to compare the performances of the proposed heuristic algorithms against each other and against that of the optimal solution. © 2003 Wiley Periodicals, Inc. Naval Research Logistics 50: 498–514, 2003
Algorithms for source‐to‐all maximum cost‐to‐time ratio problem in acyclic networks
Authors: Makri Alexandra , Klabjan Diego 
Published: July 2003

AbstractThe source‐to‐all maximum cost‐to‐time ratio problem is the problem of finding the maximum cost‐to‐time ratio path from a source node to every other node. The motivation comes from an application in large‐scale linear programming. We present three algorithms for solving the problem. We give proofs of correctness and we analyze the running times. One of the algorithms is polynomial and the remaining two are pseudopolynomial. We present extensive computational results on several networks. © 2003 Wiley Periodicals, Inc.
A general construction for nonblocking crosstalk‐free photonic switching networks
Authors: Hwang Frank K. , Lin Wen‐Dar 
Published: July 2003

AbstractThe graph representation G(M) of a multistage switching network M is well known. Lea IEEE Trans Commun 38 (1990), 529–538 observed that link‐disjoint paths in M correspond to node‐disjoint paths in G(M). He proposed G(M) as a network by treating nodes as crossbars to transfer the node‐disjoint property to the crosstalk‐free property essential for photonic networks using directional couplers as components. However, such a network has its peculiarities and is not commonly used. In this paper, we will show how to take advantage of this correspondence to construct nonblocking crosstalk‐free networks using the vertical stacking method. Our construction simplifies the proofs of many existing results, as well as establishing some new results. © 2003 Wiley Periodicals, Inc.
An exact algorithm for the Traveling Salesman Problem with Deliveries and Collections
Authors: Baldacci R. , Hadjiconstantinou E. , Mingozzi A. 
Published: July 2003

AbstractIn this paper, we describe a new integer programming formulation for the Traveling Salesman Problem with mixed Deliveries and Collections (TSPDC) based on a two‐commodity network flow approach. We present new lower bounds that are derived from the linear relaxation of the new formulation by adding valid inequalities, in a cutting‐plane fashion. The resulting lower bounds are embedded in a branch‐and‐cut algorithm for the optimal solution of the TSPDC. Computational results on different classes of test problems taken from the literature indicate the effectiveness of the proposed method. © 2003 Wiley Periodicals, Inc.
The spectra of wrapped butterfly digraphs
Authors: Comellas Francesc , Fiol Miquel Angel , Gimbert Joan , Mitjana Margarida 
Published: July 2003

AbstractThe knowledge of the spectrum of a (di)graph is relevant for estimating some of its structural properties, which provide information on the topological and communication properties of the corresponding networks. Among these properties, we have, for instance, edge‐expansion and node‐expansion, bisection width, diameter, maximum cut, connectivity, and partitions. In this paper, we determine the complete spectra (eigenvalues and multiplicities) of wrapped butterfly digraphs. © 2003 Wiley Periodicals, Inc.