bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of intracerebral insulin in the effect of nutrition on gonadotrophin secretion in mature male sheep
Authors: Miller D W , Blache D , Martin G B
Published: December 2008

The effect of nutrition on gonadotrophin secretion may be exerted through a central metabolic signal that reflects nutritional status. We have previously found that glucose and insulin concentrations are elevated in the cerebrospinal fluid (CSF) of rams in which the secretion of gonadotrophins has been stimulated by a nutritional supplement of lupin grain (Lupinus angustifolius). In the present study, we tested the hypothesis that insulin and/or glucose is a metabolic modulator of GnRH secretion and mediates the effects of nutrition on gonadotrophin secretion. Six mature rams were fed a diet that maintained live weight and then given a series of infusions, each for 12 h/day for 4 days, in a cross-over design. The treatments were: artificial CSF (aCSF), glucose (50 μmol/h) in aCSF, insulin (0·6 ng/h) in aCSF, and glucose (50 μmol/h) plus insulin (0·6 ng/h) in aCSF; all infused at a rate of 5 μl/min. At the same time as the infusion treatments, two other groups of four rams without cerebral cannulae were fed either the maintenance diet or the same diet supplemented with 750 g lupin grain per head per day for 4 days, again in a cross-over design. Rams fed the lupin supplement showed an increase in both LH pulse frequency and mean FSH on day 4 (P<0·05). Infusion of aCSF or glucose did not affect gonadotrophin secretion. Rams infused with insulin or insulin plus glucose showed an increase (P<0·05) in LH pulse frequency but no increase in FSH concentrations on day 4 of infusion. The magnitude of the LH response to insulin was similar to the nutritional response of feeding lupin supplements. There was no effect of any of the infusion treatments on plasma prolactin or insulin secretion. These data show that changes in insulin concentrations in the CSF lead to changes in LH secretion and support the hypothesis that insulin is a metabolic modulator of GnRH secretion and mediates the effects of nutrition on gonadotrophin secretion.

Journal of Endocrinology (1995) 147, 321–329
Anti-progesterone effects on maternal recognition and behaviour imprinted during first pregnancy in mice
Authors: Crombie D L , Hayes J S , Heap R B , Wang M-W
Published: December 2008

Anti-progesterone treatment using specific anti-progesterone antibodies or a progesterone receptor (PR) antagonist during first pregnancy impairs postpartum maternal behaviour in mice. This effect is demonstrable only if the treatment is given during pregnancy but not immediately after parturition. The purpose of the present studies was to investigate if maternal behaviour is also impaired by anti-progesterone treatment in subsequent pregnancies.

Studies with a monoclonal antibody to progesterone (DB3; 4·5 nmol/mouse) showed that injection of females on day 17 of second pregnancy did not cause maternal rejection but the latency of pup retrieval was prolonged especially during the first 3 days of lactation. This phenomenon was not observed in animals that had previous experience of full length lactation. Experiments were carried out with mifepristone (RU486; 10 μg/mouse) injected at day 17 of first, second or third pregnancies. Pup rejection (22·5% vs 12·3%) and prolongation of the retrieval latency (62·3 ± 13·3 vs 19·7 ± 6·5 s; P<0·02) were observed following the first pregnancy. No abnormal behavioural effects were found in mothers treated in second or third pregnancy who had prior full length lactation experience. Control females subjected to only one pup retrieval test after first delivery rejected their pups if treated in their second pregnancy (27.3% vs 4·4%; P<0·001) and displayed a marginal prolongation of the retrieval latency period (20·9 ± 7·0 vs 7·4 ± 2·6 s). Anti-progesterone treatment had no negative influence when administered during third pregnancy.

To determine whether treatment with RU486 (50 μg/mouse, day 17) during first pregnancy has any residual effects, maternal response was monitored after completion of second pregnancy where no treatment was given. Females who exhibited both maternal rejection and prolonged retrieval latency following first pregnancy did not demonstrate any carryover effects during second lactation, indicating that there is no long-term consequence of RU486 treatment. These results suggest that: (i) anti-progesterone treatment of pregnant mice prevents maternal recognition and disrupts postpartum behaviour in females who had no, or very limited, nursing experience; (ii) there is a progesterone-dependent imprinting mechanism during the first pregnancy that is disrupted by anti-progesterone antibody or PR antagonist; and (iii) this imprinting mechanism and first lactation are important components of the consolidation of neural pathways that are associated with the establishment of normal maternal behaviour.

Journal of Endocrinology (1995) 147, 331–337
The relative importance of the oligosaccharide units in human chorionic gonadotropin (CG) for LH/CG receptor activation in rat Leydig cells and mouse Leydig tumor cells
Authors: van Loenen H J , van Gelderen-Boele S , Flinterman J F , Merz W E , Rommerts F F G
Published: December 2008

The biological properties of deglycosylated human chorionic gonadotropin (DhCG), obtained by hydrogen fluoride treatment (HF-DhCG) of intact hCG or by oligonucleotide-directed mutagenesis (CHO-DhCG), and that of their fully glycosylated counterparts, were tested in terms of cAMP and steroid production in rat Leydig cells and in mouse Leydig tumor cells (MA-10 cells). In both cell types, HF-DhCG and CHO-DhCG possessed comparable biological activities. The maximum for DhCG-induced cAMP production was approximately 12% of that of intact hCG when tested in rat Leydig cells, and only 2% when tested in MA-10 cells. DhCG possessed significant steroidogenic activity in both cell types. In MA-10 cells the maximum for DhCG-induced steroidogenesis was 30–50% of that of intact hCG, while in rat Leydig cells DhCG and hCG induced similar steroidogenic maxima. Based on its ED50, DhCG possessed 10–17% of the steroidogenic potency of intact hCG in rat Leydig cells, while in MA-10 cells DhCG was only 2-fold less potent than hCG. When accurate hormone-receptor binding data are absent, the intrinsic receptor-stimulating activity of a ligand can still be estimated at full receptor occupancy, provided that over the whole dose range the biological response is proportional to receptor stimulation. The present data show that in transfected MA-10(P+29) cells which over-express rat phosphodiesterase, the hormone-induced stimulation of cAMP and steroid production is directly coupled to receptor activation up to maximal occupation of the LH/CG receptor. The intrinsic receptor-stimulating activity of DhCG, measured in MA-10(P+29) cells in terms of DhCG-induced steroidogenesis, appeared to be 7- to 10-fold lower than that of intact hCG. As it is known from the literature that DhCG possesses 2- to 3-fold higher affinity to the LH/CG receptor than intact hCG, this increased binding affinity of DhCG may partly compensate for the 7- to 10-fold reduction in the intrinsic receptor-stimulating activity, resulting in only a 2-fold reduction in steroidogenic potency of DhCG. In terms of adenylyl cyclase stimulation in MA-10(P+29) cells, DhCG possessed approximately 50-fold lower receptor-stimulating activity than intact hCG, being similar to that observed in wild-type MA-10 cells. This study clearly shows that the oligosaccharide units in hCG are not essential for LH/CG receptor activation, and that the relative receptor-stimulating activity of DhCG to that of hCG is highly dependent on whether cAMP or steroid production is measured as an index for bioactivity, and whether bioactivity is tested in rat Leydig cells or MA-10 cells.

Journal of Endocrinology (1995) 147, 367–375
1,25-Dihydroxyvitamin D3-induced upregulation of the thyrotropin-releasing hormone receptor in clonal rat pituitary GH3 cells
Authors: Atley L M , Lefroy N , Wark J D
Published: December 2008

1,25-Dihydroxyvitamin D3 (1,25-(OH)2D3) is active in primary dispersed and clonal pituitary cells where it stimulates pituitary hormone production and agonist-induced hormone release. We have studied the effect of 1,25-(OH)2D3 on thyrotropin-releasing hormone (TRH) binding in clonal rat pituitary tumour (GH3) cells. Compared with vehicle-treated cells, 1,25-(OH)2D3 (10 nmol/l) increased specific [3H]MeTRH binding by 26% at 8 h, 38% at 16 h, 35% at 24 h and reached a maximum at 48 h (90%). In dose–response experiments, specific [3H]MeTRH binding increased with 1,25-(OH)2D3 concentration and reached a maximum at 10 nmol/l. Half-maximal binding occurred at 0·5 nmol 1,25-(OH)2D3/l. The vitamin D metabolite, 25-OH D3, increased [3H]MeTRH binding but was 1000-fold less potent than 1,25-(OH)2D3. In equilibrium binding assays, treatment with 10 nmol 1,25-(OH)2D3/l for 48 h increased the maximum binding from 67·4 ± 8·8 fmol/mg protein in vehicle-treated cells to 96·7 ± 12·4 fmol/mg protein in treated cells. There was no difference in apparent Kd (1·08 ± 0·10 nmol/l for 1,25-(OH)2D3-treated and 0·97 ± 0·11 nmol/l for vehicle-treated cells). Molecular investigations revealed that 10 nmol 1,25-(OH)2D3/l for 24 h caused an 8-fold increase in TRH receptor-specific mRNA. Actinomycin D (2 μg/ml, 6 h) abrogated the 1,25-(OH)2D3-induced increase in [3H]MeTRH binding. Cortisol also increased [3H]MeTRH binding but showed no additivity or synergism with 1,25-(OH)2D3. TRH-stimulated prolactin release was not enhanced by 1,25-(OH)2D3. We conclude that the active vitamin D metabolite, 1,25-(OH)2D3, caused a time- and dose-dependent increase in [3H]MeTRH binding. The effect was vitamin D metabolite-specific and resulted from an upregulation of the TRH receptor. Further studies are needed to determine the functional significance of this novel finding.

Journal of Endocrinology (1995) 147, 397–404
Neural expression of the pituitary GH gene
Authors: Render C L , Hull K L , Harvey S
Published: December 2008

It is well established that GH-like proteins and mRNA are present in extrapituitary tissues, but it is not known whether this reflects ectopic transcription of the pituitary GH gene or the expression of a closely related gene. This possibility was, therefore, further investigated.

Immunoreactive (IR) GH-like proteins were readily measured by RIA and immunoblotting in hypothalamic and extrahypothalamic brain tissues of the domestic fowl, in which GH-IR was similar in size and antigenicity to pituitary GH. RT-PCR of mRNA from these brain tissues, with oligonucleotide primers spanning the coding region of pituitary GH cDNA, also generated cDNA fragments identical in size (689 bp) to pituitary GH cDNA. The amplified brain cDNA sequences contained BamH1 and Rsa1 cleavage sites similar to those located in pituitary GH cDNA. These cDNA sequences also hybridized with a cDNA probe for chicken GH cDNA, producing moieties of expected size that were identical to the hybridizing moieties in pituitary tissue. The nucleotide sequences of the PCR products generated from hypothalamic and extrahypothalamic brain tissues, determined by a modified cycle dideoxy chain termination method, were also identical to pituitary GH cDNA. This homology extended over 594 bp of the hypothalamic cDNA fragment (spanning nucleotides 65 to 659 of the pituitary GH cDNA and its coding region for amino acids 4 to 201) and 550 bp of the extrahypothalamic cDNA fragment (spanning nucleotides 76 to 626 of pituitary GH cDNA and its coding region for amino acids 8 to 190).

These results clearly establish that pituitary GH mRNA sequences are transcribed in hypothalamic and extrahypothalamic tissues of the chicken brain, in which GH-IR proteins are abundantly located. However, as GH mRNA could not be detected in the chicken brain by Northern blotting, its turnover may be more rapid than in pituitary tissue. The local production of GH within the brain nevertheless suggests that it has paracrine roles in modulating neural or neuroendocrine function.

Journal of Endocrinology (1995) 147, 413–422
Differential regulation of plasma levels of insulin-like growth factors-I and -II by nutrition, age and growth hormone treatment in sheep
Authors: Hua K M , Hodgkinson S C , Bass J J
Published: December 2008

Plasma levels of IGFs-I and -II were measured in 4-month-old ewe lambs (n=20) and 2-year-old ewes (n=16), which were well fed (n=18) or fasted (n=18) for 3 days. Half of each nutrition group was given daily (0900 h) injections of bovine GH (bGH, 0·1 mg/kg body weight per day) for 3 days. Blood samples were collected immediately before the GH injection every morning.

Plasma IGFs were extracted by acid gel permeation chromatography using a Waters Protein Pak 125 column, fitted to a Pharmacia fast protein liquid chromatography system, then freeze-dried, reconstituted (at pH 7·4) and estimated by RIA.

At the end of the experiment, IGF-I levels in plasma were increased (P<0·01) by exogenous bGH in both fed ewes and lambs but not in the fasted animals; plasma IGF-I levels were depressed by fasting (P<0·01) at all ages. IGF-I levels were also found to be significantly higher (P<0·01) in ewes than lambs.

In contrast, plasma IGF-II concentrations were depressed (P=0·02) by administration of bGH in all groups and elevated in the ewes (P<0·05) by fasting. However, the lambs showed no significant changes in IGF-II with fasting. The IGF-II levels were significantly higher (P<0·001) in lambs than ewes.

Results from the present study demonstrate that GH administration stimulated an increase in plasma IGF-I and induced a decrease in plasma IGF-II. On the other hand, fasting depressed plasma IGF-I and elevated plasma IGF-II in the sheep. A significant GH/nutrition interaction for IGF-I (P<0·01), but not for IGF-II, and a significant nutrition/age interaction for IGF-II (P<0·01), but not for IGF-I, in the present study suggest that GH has a greater stimulating effect on plasma levels of IGF-I in the fed rather than fasted sheep and that nutrition has a greater influence on plasma levels of IGF-II in the older rather than younger animals, indicating that plasma IGFs-I and -II are differentially regulated by nutrition, GH and developmental stage in postnatal sheep.

Journal of Endocrinology (1995) 147, 507–516
Could abnormalities in insulin-like growth factors and their binding proteins during pregnancy result in gestational diabetes?
Authors: Cwyfan Hughes S C , Johnson M R , Heinrich G , Holly J M P
Published: December 2008

A number of dramatic changes have been documented in the insulin-like growth factors (IGFs-I and -II) and their binding proteins (IGFBPs) during pregnancy. In this study we have tested the hypothesis that a failure of the normal proteolytic modification of IGFBP-3 is responsible for gestational diabetes by examining serum samples taken in the third trimester from 29 women with uncomplicated pregnancies, 21 women with established Type 1 diabetes and 20 women with gestational diabetes. Analysis of IGFBP-3 by Western immunoblotting revealed that it was present in a modified form, migrating at around 29 kDa, in the circulation of all of the women investigated. Semiquantification of the activity of the protease which modifies the IGFBP-3 demonstrated considerable variation between individuals in their ability to fragment radiolabelled IGFBP-3 following a 45-min co-incubation. Surprisingly, in one individual (with gestational diabetes) there was no detectable protease activity even though her endogenous IGFBP-3 had been modified. However, overall there was no clear-cut difference in protease activity between the different groups.

Radioimmunometric analysis of IGF-I revealed significantly higher levels in women with gestational diabetes than either of the other two groups (P<0·05). Similarly IGFBP-3 levels were also increased in these same women (P<0·05). In contrast, IGF-II levels did not alter between the three groups.

In conclusion, our hypothesis was not supported by these data and gestational diabetes was found not to be associated with any reduction in the activity of the circulating IGFBP-3 protease which could have decreased the availability of the IGF nor with any alteration in IGFs which could explain the onset of diabetes in these women.

Journal of Endocrinology (1995) 147, 517–524
Stimulation of hepatic insulin-like growth factor-binding protein-1 and -3 gene expression by octreotide in rats
Authors: Flyvbjerg A , Schuller A G P , van Neck J W , Groffen C , Ørskov H , Drop S L S
Published: December 2008

It has recently been demonstrated in various clinical experiments that native somatostatin and its long-acting analogues increase circulating levels of insulin-like growth factor-binding protein-1 (IGFBP-1) within 1–2 h, independent of effects on circulating insulin or glucose levels. Using human hepatoma cells in vitro the somatostatin analogue, octreotide, has been shown to increase IGFBP-1 mRNA within 24 h indicative of a direct stimulatory effect of octreotide on IGFBP-1 synthesis. In order to ascertain whether octreotide acutely stimulates IGFBP-1 mRNA in vivo, placebo or two doses of octreotide were injected subcutaneously into three groups of rats. One hour after saline or octreotide administration, liver, kidney and serum were obtained for the measurement of IGFBPs-1 to -6 mRNA in tissue and IGFBPs and IGF-I in serum. Octreotide increased liver IGFBP-1 (562%) and IGFBP-3 (23%) mRNA expression with a concomitant rise in the circulating 30 kDa (106%) and 38–42 kDa (23%) IGFBPs. No detectable changes were seen in other liver IGFBP transcripts, other circulating IGFBPs or in any of the kidney IGFBP transcripts. Serum IGF-I increased by 37% in the animals receiving the high octreotide dose. No concomitant changes were observed in glucose or insulin levels.

These data show that octreotide acutely stimulates hepatic IGFBP-1 and -3 mRNA in vivo in rats. The stimulating effect on IGFBP-3 presents a possible hitherto unknown form of regulation of IGFBP-3 whilst the effect on IGFBP-1 indicates that the stimulatory effect of octreotide on circulating IGFBP-1 described in clinical trials may be due to increased hepatic production. The present findings may be of importance in the clinical use of octreotide.

Journal of Endocrinology (1995) 147, 545–551
Menstrual cycle specific expression of epidermal growth factor receptors in human fallopian tube epithelium
Authors: Adachi K , Kurachi H , Adachi H , Imai T , Sakata M , Homma H , Higashiguchi O , Yamamoto T , Miyake A
Published: December 2008

We studied the expression of epidermal growth factor (EGF) receptor protein and messenger RNA (mRNA) in human fallopian tubes at three stages of the menstrual cycle: early follicular (n=3), late follicular (n=3) and luteal (n=3). Immunohistochemical studies in the ampullary portion of the tubes showed that specific staining was localized to the epithelium and the vascular endothelium. Staining of the epithelium was intense at the late follicular and luteal stages, while it was weak at the early follicular stage. 125I-EGF binding study in the tubal plasma membranes revealed a class of high-affinity EGF receptors. Although dissociation constants were similar between the stages, numbers of binding sites at the late follicular and luteal stages were significantly (P<0·01) greater than those at the early follicular stage. Western blotting showed that tubal plasma membranes contain Mr 170 000 EGF receptor protein. The amounts were significantly (P<0·01, n=3) greater at the late follicular and luteal stages than those at the early follicular stage. Reverse transcription and polymerase chain reaction (RT-PCR) revealed that EGF receptor mRNA was expressed in all the 9 RNA samples (n=3 for each stage) from the tubal ampullary portion. The amounts were significantly (P<0·01, n=3) greater at the late follicular and luteal stages than those at the early follicular stage (by a competitive PCR). Increase in the amounts of EGF receptor protein and mRNA occurred in association with an increase in serum oestradiol but not progesterone levels. Next we examined whether EGF receptor and its ligands (EGF and transforming growth factor a) are directly induced by oestrogen. We found that specific staining for EGF receptor and its ligands in the tubal epithelium was detected (by immunohistochemistry) in postmenopausal women with oestrogen replacement (n = 3), but not in subjects without oestrogen replacement (n=3). These results suggested that EGF receptors in the human tubal epithelium are expressed in relation to specific stages of the menstrual cycle and that the expression may be induced by oestrogen.

Journal of Endocrinology (1995) 147, 553–563
AGOUTI PROTEIN CAN ACT INDEPENDENTLY OF MELANOCYTE-STIMULATING HORMONE TO INHIBIT MELANOGENESIS
Authors: HUNT G , THODY A J
Published: December 2008

In animals, the coat-darkening effects of α-melanocyte stimulating hormone (α-MSH) are opposed by agouti protein. Although agouti protein has been shown to be a competitive antagonist of the melanocyte-associated MC-1 melanocortin receptor, the possibility that agouti protein can affect melanogenesis independently of its ability to antagonise melanocortin activity cannot be excluded. This study demonstrates that murine agouti protein causes both a time- and concentration-dependent suppression of melanogenesis in B16 F1 murine melanoma cells. In addition, human agouti protein decreases melanogenesis in cultured human epidermal melanocytes. However, agouti protein has little effect on the ability of α-MSH to stimulate melanogenesis. These observations raise fundamental questions about the mode of action of agouti protein in regulating melanogenesis.
IL-6sR: RELEASE FROM MCF-7 BREAST CANCER CELLS AND ROLE IN REGULATING PERIPHERAL OESTROGEN SYNTHESIS
Authors: Singh A. , Purohit A. , Wang D.Y. , Duncan L.J. , Ghilchik M.W. , Reed M.J.
Published: December 2008

The interleukin-6 soluble receptor (IL-6sR) may regulate the ability of IL-6 to stimulate oestrogen synthesis in breast cancer cells and breast tumours. Significant aromatase activity was detectable in IL-6 stimulated fibroblasts derived from subcutaneous adipose tissue, but the combination of IL-6sR plus IL-6 resulted in a marked 21-fold stimulation of aromatase activity. To examine the control of IL-6sR release, the effects of oestradiol, 4-hydroxytamoxifen (4-OHT), dexamethasone, TPA, TNFα or IL-6 on this process was examined using MCF-7 breast cancer cells. Oestradiol, TNFα and dexamethasone all markedly increased IL-6sR release. While 4-OHT had a small stimulatory effect on IL-6sR release, it blocked the ability of oestradiol to increase IL-6sR release. Significant concentrations of IL-6sR were also detected in conditioned medium collected from lymphocytes and macrophages and in cytosols prepared from normal and malignant breast tissues. These results indicate that IL-6sR may have an important role in potentiating the effect of IL-6 on oestrogen synthesis in breast cancer cells. The abilities of oestradiol or tamoxifen to potentiate or inhibit the IL-6 stimulation of oestrogen synthesis in breast cancer cells may result from their effects on IL-6sR release.
Briefing: Alternative dispute resolution techniques
Authors: Tait J. N.
Published: December 2008

The title of this briefing, ‘Alternative dispute resolution techniques’, rather begs the question ‘alternative to what?’ For the purposes of this paper the answer is ‘litigation and arbitration’. The aim of the paper is to provide an overview of the many alternatives on offer and the terminology used to describe them. Although not all of the alternatives described are directly relevant to the construction process all are relevant to the commercial activities in which all organisations and individuals connected with the construction process become involved in their day-to-day work.
Employer perspective of the new Irish public works contract
Authors: Masterson J.
Published: December 2008

The objective of this paper is to set out the headline issues to be considered when preparing the new Irish public works contracts for tender. The first section provides a general introduction, which is followed by an explanation of when the new contracts should be used and a description of the different forms of the new contract that are available. The next section describes the new mindset for drafting the drawings and specification, in particular in relation to preserving the lump sum and selecting sub-contractors. Risk allocation, in particular the use of the optional compensation events, is explained in the fifth section and the sixth considers the administrative requirements of the new contract that will need to be taken into account when preparing the tender. The untypical items in the schedule to the new contract that needs to be completed by the public authority are then listed and the final section contains a short conclusion. Two useful tables are also included: one sets out certain of the employer’s risks in the public works contract previously used in Ireland (the IEI) and analyses whether these are included in the Government Contracts Committee for Construction (GCCC) contract, and the other sets out certain of the contractor’s administrative requirements under the GCCC contract and analyses whether these are included in the IEI.
Near-Surface External-Casing Corrosion in Alaska: Cause and Mitigation
Authors: Dethlefs Jerald , Blount Curtis , Bollinger John
Published: December 2008

Recently, a number of external-casing failures on a group of relatively new wells in the Kuparuk field of Alaska prompted an investigation into the cause. The investigation determined that external surface-casing-corrosion failures had occurred near the top of the casing cement within the conductor.

The surface-casing corrosion was found to be caused by repetitive events of surface water entering into the top of the annulus between the surface casing and the conductor above the primary cement top. Testing of water and cement samples taken from the field indicates that the addition of oxygenated water and chemical salts that leach from the cement creates a low-resistance electrolyte resulting in an extremely corrosive environment. The yearly replenishment of oxygenated water in this environment sets up an electrochemical cell that corrodes the surface casing. Elevated casing temperatures (≈125°F) accelerate the corrosion rates and increase the temperature gradient between the casing and the conductor, creating a thermogalvanic-corrosion cell.

Although damaged surface casing has been repaired mechanically on numerous wells by excavation and installation of welded sleeve patches, accessing the damaged surface casing can be difficult. Inhibiting the corrosion mechanism is considered a more tenable solution.

This paper will

Provide an outline of the extent of shallow external-casing corrosion seen in the field. Detail the mechanisms for the external corrosion. Detail the mechanical-repair procedures used to return the wells to service. Discuss possible mitigation methods to inhibit corrosion on existing wells. Discuss the treatment chosen to stop the corrosion. Provide details of treatments used to inhibit further shallowcasing corrosion.
Stressed-Shale Drilling Strategy—Water-Activity Design Improves Drilling Performance
Authors: Zhang Jianguo , Rojas Juan Carlos , Clark David E.
Published: December 2008

Nonaqueous drilling fluids are often chosen to drill troublesome shale formations in an effort to minimize wellbore-instability problems. However, experience in the Gulf of Mexico (GOM) indicates that when drilling in highly faulted areas, oil- and synthetic-based fluids do not always prevent wellbore destabilization. This is evidenced by wellbore collapse, and the resulting difficulty with hole cleaning, tripping, logging, and casing running.

It is known that the chemical, physical, and mechanical effects resulting from the interaction between the drilling fluid and the formation may degrade the stability of the borehole in the already weakened and stressed fault interval. Commonly, the practice has been to increase the drilling fluid's salt content to enhance the borehole stability. The perception that low drilling-fluid water activity is beneficial to wellbore stability needs to be revised.

A detailed laboratory investigation using preserved-shale core and drilling information has confirmed that the water activity of drilling fluids is often much lower than necessary. This study has shown that when drilling faulted or fractured shale, the correct, not higher, salt content in drilling fluids will reduce wellbore-collapse problems and improve drilling performance.

A laboratory method, which allows the quantitative measurement of water and ion movement during shale/mud interactions, combined with geological information optimizes the salinity design of drilling fluid, which controls water and ion movement. Laboratory data and field cases from GOM drilling support the concept of optimum salinity to enhance borehole stability in naturally fractured formations as part of the stressed-shale-drilling strategy to improve drilling performance.
The Role of Knowledge, Tools, and Systems for Drilling Analysis
Authors: Lagreca Alejandro J. , Damski Carlos , Peden James M. , Nakagawa Edson Y.
Published: December 2008

This paper proposes a methodical structure to embody current expertise for the analysis of drilling data. This structure is based on two aspects: (1) the review of published literature, representative of present-day efforts to perform such tasks, and (2) the use of the methodological-pyramid concept, to illustrate what elements typify a methodology.

The review of published works revealed that several key aspects of the analysis of drilling data are not clear; for example

Actual use of drilling data is still unclear and under debate. Most of the available engineering tools limit the range of applications to drilling-performance estimators. The proposed methods of analysis vary, depending upon the needs of individual organizations or processes using the concept of "method and methodology" indistinctly. Various sets of concepts and theories, from internal and external sources, of drilling-engineering knowledge have been used to develop existing methods and engineering tools.

Under this scenario, it seems that more effort is needed to unify current approaches to analyze drilling data (i.e., within the scope of an independent field with common goals, theories, methods, and tools that can support the decision-making process). For this purpose, the methodological pyramid was chosen as a convenient model to outline these efforts. By allocating some of the reviewed approaches within the elements of such a pyramid and contrasting their different ideas where necessary, a methodology for drilling analysis was formalized. It is believed that this methodology is a convenient framework for defining the goals and scope for an area of drilling expertise named "drilling analysis" and defining the evolving future role of the drilling analyst.
Heat Treatment Improves Glucose Tolerance and Prevents Skeletal Muscle Insulin Resistance in Rats Fed a High-Fat Diet
Authors: Gupte Anisha A. , Bomhoff Gregory L. , Swerdlow Russell H. , Geiger Paige C.
Published: December 2008

OBJECTIVE—Heat treatment and overexpression of heat shock protein 72 (HSP72) have been shown to protect against high-fat diet–induced insulin resistance, but little is known about the underlying mechanism or the target tissue of HSP action. The purpose of this study is to determine whether in vivo heat treatment can prevent skeletal muscle insulin resistance.

RESEARCH DESIGN AND METHODS—Male Wistar rats were fed a high-fat diet (60% calories from fat) for 12 weeks and received a lower-body heat treatment (41°C for 20 min) once per week.

RESULTS—Our results show that heat treatment shifts the metabolic characteristics of rats on a high-fat diet toward those on a standard diet. Heat treatment improved glucose tolerance, restored insulin-stimulated glucose transport, and increased insulin signaling in soleus and extensor digitorum longus (EDL) muscles from rats fed a high-fat diet. Heat treatment resulted in decreased activation of Jun NH2-terminal kinase (JNK) and inhibitor of κB kinase (IKK-β), stress kinases implicated in insulin resistance, and upregulation of HSP72 and HSP25, proteins previously shown to inhibit JNK and IKK-β activation, respectively. Mitochondrial citrate synthase and cytochrome oxidase activity decreased slightly with the high-fat diet, but heat treatment restored these activities. Data from L6 cells suggest that one bout of heat treatment increases mitochondrial oxygen consumption and fatty acid oxidation.

CONCLUSIONS—Our results indicate that heat treatment protects skeletal muscle from high-fat diet–induced insulin resistance and provide strong evidence that HSP induction in skeletal muscle could be a potential therapeutic treatment for obesity-induced insulin resistance.
Interaction Effect of Genetic Polymorphisms in Glucokinase (GCK) and Glucokinase Regulatory Protein (GCKR) on Metabolic Traits in Healthy Chinese Adults and Adolescents
Authors: Tam Claudia H.T. , Ma Ronald C.W. , So Wing Yee , Wang Ying , Lam Vincent K.L. , Germer Soren , Martin Mitchell , Chan Juliana C.N. , Ng Maggie C.Y.
Published: December 2008

OBJECTIVE— Recent studies in European populations have reported a reciprocal association of glucokinase regulatory protein (GCKR) gene with triglyceride versus fasting plasma glucose (FPG) levels and type 2 diabetes risk. GCKR is a rate-limiting factor of glucokinase (GCK), which functions as a key glycolytic enzyme for maintaining glucose homeostasis. We examined the associations of two common genetic polymorphisms of GCKR and GCK with metabolic traits in healthy Chinese adults and adolescents.

RESEARCH DESIGN AND METHODS— Two single nucleotide polymorphisms (SNPs), rs780094 at GCKR and rs1799884 at GCK, were genotyped in 600 healthy adults and 986 healthy adolescents. The associations of these SNPs with metabolic traits were assessed by linear regression adjusted for age, sex, and/or BMI. We also tested for the epistasis between these two SNPs and performed a meta-analysis among European and Asian populations.

RESULTS— The T-allele of GCKR rs780094 was associated with increased triglycerides (P = 5.4 × 10−7), while the A-allele of GCK rs1799884 was associated with higher FPG (P = 3.1 × 10−7). A novel interaction effect between the two SNPs on FPG was also observed (P = 0.0025). Meta-analyses strongly supported the additive effects of the two SNPs on FPG and triglycerides, respectively.

CONCLUSIONS— In support of the intimate relationship between glucose and lipid metabolisms, GCKR and GCK genetic polymorphisms interact to increase FPG in healthy adults and adolescents. These risk alleles may contribute to increased diabetes risk in subjects who harbor other genetic or environmental/lifestyle risk factors.
A Modified Subpulse SAR Processing Procedure Based on the Range-Doppler Algorithm for Synthetic Wideband Waveforms
Authors: Lim Byoung-Gyun , Woo Jea-Choon , Lee Hee-Young , Kim Young-Soo
Published: December 2008

Synthetic wideband waveforms (SWW) combine a stepped frequency CW waveform and a chirp signal waveform to achieve high range resolution without requiring a large bandwidth or the consequent very high sampling rate. If an efficient algorithm like the range-Doppler algorithm (RDA) is used to acquire the SAR images for synthetic wideband signals, errors occur due to approximations, so the images may not show the best possible result. This paper proposes a modified subpulse SAR processing algorithm for synthetic wideband signals which is based on RDA. An experiment with an automobile-based SAR system showed that the proposed algorithm is quite accurate with a considerable improvement in resolution and quality of the obtained SAR image.
Innovative electronic auctions in supply and demand chains: Empirical research in the flower industry
Authors: van Heck Eric
Published: December 2008

Exploiting the Internet for commercial ends has become a key theme for most organizations. There are significant advantages for both buyers and sellers in using this medium. Savings are made as a result of reducing transaction costs, increasing the circle of potential customers, and improving the search-and-find capabilities for all parties concerned. At the moment there are several hundred Web-based auctions. And yet the place to see state-of-the-art auctions is not on the Web but rather in one of the dozen or so auction halls in Holland. This article analyses different electronic auction initiatives in the Dutch flower industry. These auctions use the “Dutch auction” as price discovery process. In a Dutch auction the auctioneer offers products at successively lower prices until his offer is accepted. Most auctions on the Web today use the English method. An English auction process involves a succession of increasing bids by potential buyers until the highest (and final) bid is accepted by the auctioneer. But the Dutch method offers advantages, as the flower auctions reveal. The Dutch method is much faster and tends to generate higher prices. This is illustrated by presenting the results of experimental economic research with different Web-based auctions. One of the analysed electronic auction initiatives, Tele Flower Auction, shows that electronic auctions have an impact on the chain configuration and its performance. Conclusions are formulated and further research is discussed.
Designating the driver: Establishing a cooperative distribution network in Japan
Authors: Hagen James M. , Hayashi Katsumasa
Published: December 2008

This article is an exploratory case study, which describes the recent evolution of a distribution network for ice cream in Japan and explores the forces behind that evolution. The case incorporates the perspectives of actors at the manufacturing, wholesaling, and retail levels. In examining how a particular distribution structure evolved among these parties, we suggest that the resulting structure was a response to environmental changes. We identify power and efficiency as driving forces behind the network architecture, and we identify mechanisms used to facilitate trust between the parties.
A Research and Management Agenda for Chain and Network Science
Authors: (Onno) Omta S. , Trienekens Jacques , Beers George
Published: December 2008

In the present editorial we address key issues and research questions in the field of chain and network science. Theoretical approaches discussed in this editorial include Network Theory, Supply Chain Management and Industrial Organisation Theory. Major research themes derived from these approaches are formulated in the conclusions. The editorial ends with the management implications of the different articles in this issue.
Food supply chains: Are efficiency and responsiveness mutually exclusive?
Authors: Koops Sven , Mollenkopf Diane , Zwart Tony
Published: December 2008

This article presents the empirical results of a study of strategic change in 291 organisations operating in New Zealand food supply chains. Firms in food-related businesses have been increasingly responsive to changing customer demands and competitive pressures and have introduced substantial product and process changes. This research considers firm-internal and supply chain relationship characteristics as the cause of strategic change. Using structural equation modelling, significant relationships between firm resources and strategic change were sought. Multi-group analyses were used to identify moderating effects of supplier and customer collaboration. The results indicate that resources have an effect on product and process changes. Supplier and customer collaboration were not found to have any moderating effects. The results have important implications for both supply chains and firms in terms of strategic change and the benefits of supplier and customer collaboration.
Co-operating to compete in high velocity global markets: The strategic role of flexible supply chain architectures
Authors: Gow Hamish , Oliver Lance , Gow Neil
Published: December 2008

Continued value creation is paramount for the survival of firms competing in today's high velocity global business environment. This paper presents a conceptual framework for understanding how firms can create and capture value within a highly volatile and uncertain business environment by exploiting both performance gaps and opportunity gaps through the development and use of flexible supply chain architectures. The choice of flexible organizational architecture allows for the continued reconfiguration of the independent modular components of the supply chain so as to achieve optimal leverage of both the firms core competencies as well as their collaborative partners complementary resources. The case of Cellars of Canterbury, a New Zealand based International wine marketing and distribution cooperative enterprise provides empirical support.
"More instead of less" - Strategies for the use of logistics resources
Authors: Gadde Lars Erik , Håkansson Håkan , Jahre Marianne , Persson Gøran
Published: December 2008

This paper presents the theoretical background for a recently initiated research programme on the utilisation and development of logistics resources in supply and distribution networks. The paper opens with a discussion of previous approaches to logistics with a particular focus on whether and how resources have been dealt with. We conclude that attention has mainly been directed toward processes and activities, while resources have primarily been regarded as the means to an end. Further, we identify a need to focus on networks rather than supply chains since all companies belong to more than one chain. Accordingly, it is suggested that considering logistics networks in terms of inter-linked resources provides a fruitful complement to existing models. We continue by presenting some basic features of resources in general and by developing the foundations of the framework that is to be applied in the research programme. The basic building blocks are four types of resources that are crucial in logistics: facilities, products, business units and business relationships. Finally, three main research issues are derived from this framework.
Structural change or logical incrementalism? Turbulence in the global meat system
Authors: Goldsmith Peter , Salvador Antonio , Knipe Dar , Kendall Elaine
Published: December 2008

In the last ten years the global meat industry has encountered numerous critical events related to food safety and food quality. These events in turn have caused the industry to re-evaluate how the meat supply chain functions and how to service the new social attributes demanded in the market place. This paper uses a unique methodology, shedding light on why and how the US meat industry is evolving and why its evolutionary path may differ from that which is occurring in Europe.
Co-operatives in chains: institutional restructuring in the Dutch fruit and vegetable industry
Authors: Bijman Jos , Hendrikse en George
Published: December 2008

Co-operatives play a major role in the agricultural and food industry. Co-operatives, by their very nature, are producer-oriented firms. As market conditions for food products have changed in recent decades, the question has been raised of whether co-operatives are still efficient organisations for carrying out transactions with agrifood products? This article addresses this question for the fresh produce industry in the Netherlands. Traditionally, fruits and vegetables were sold through auctions organised by grower-owned co-operatives. In the 1990s several auction co-operatives merged, transformed into marketing co-operatives, and vertically integrated into wholesale. In addition, growers set up many new bargaining associations and marketing co-operatives. These new co-operatives have started crop and variety-specific marketing programmes. For reasons of asymmetric information and investment-related transaction costs several of the new co-operative firms have also included the wholesale function.
Identifying the determinants of value in the U.K. red meat industry: A value chain analysis approach
Authors: Simons David , Francis Mark , Bourlakis Michael , Fearne Andrew
Published: December 2008

Value Chain Analysis (VCA) is a tool for analysing the nature and source of value within a supply chain and the potential for reducing waste therein, with the focus explicitly on the determinants of value within a manufacturing process rather than the simple measurement of process outputs. The tool has been successfully applied in recent years within the motor and information technology industries, to assist forward thinking businesses to survive in an increasingly competitive environment. VCA within the food industry faces the challenge where transactional relationships between trading partners remain the norm. This paper reports the results from the first of a series of Government sponsored VCA projects in the U.K. red meat industry. The paper explains the rational for VCA, describes the methodology and reports the findings from a case study involving a food multiple retailer, a meat processor and a livestock producer. Insights are presented into the potential for the use of VCA in the U.K. food industry and the specific issues that researchers need to be mindful of when embarking on a VCA project. The paper concludes by identifying key areas in which further research is required to develop the methodology to suit the unique characteristics of the food industry.
Assuring Quality: Roles of Appraisers and Peer Reviewers
Authors: DeSilets Lynore D. , Dickerson Pamela S.
Published: December 2008

Nurses seeking continuing education opportunities have a right to know that their educational choices are well advised. Within the accreditation process, appraisers and peer reviewers play a significant role in determining that standardized criteria for continuing nursing education activities, providers, and approvers are met.
Shine On: Achieving Career Satisfaction as a Registered Nurse
Authors: Perry Beth
Published: December 2008

This phenomenological study focuses on the experience of career satisfaction among registered nurses. Potential participants were asked, “Do you love your work as a nurse?” A random sample of eight nurses who answered yes to this question was questioned further during semistructured conversations. Conversations were recorded and transcribed. Data collected were in the form of descriptions of times during the participants’ careers when they felt most professionally fulfilled. Through narrative and poetic analysis, themes of “upholding the vulnerable,” “going the extra mile,” and “attending to the essential ordinary” were identified. Nurse educators play an important role facilitating career satisfaction for registered nurses. Practical implications for continuing education for educators and practicing nurses are addressed.
Grief Experiences of CNAs: Relationships with Burnout and Turnover
Authors: Anderson Keith A.
Published: December 2008

The deaths of nursing home residents can significantly affect staff members. The purpose of this quantitative study was to investigate whether work-related grief contributes to burnout and turnover in certified nursing assistants (CNAs). Participants (N = 136) from 12 nursing homes completed self-administered surveys. Regression analyses revealed that complications from grief can contribute to burnout, whereas positive reactions to grief can protect CNAs from burnout. Grief was not found to be a significant predictor of turnover; however, grief may have a more complex, indirect influence on turnover than had been anticipated.