bluuebunny/crossref_metadata_2025 huggingface dataset:
CCR2-V64I polymorphism is associated with increased risk of cervical cancer but not with HPV infection or pre-cancerous lesions in African women
Authors: Chatterjee Koushik , Dandara Collet , Hoffman Margaret , Williamson Anna-Lise
Published: June 2010

Background

Cervical cancer, caused by specific oncogenic types of human papillomavirus (HPV), is the second most common cancer in women worldwide. A large number of young sexually active women get infected by HPV but only a small fraction of them have persistent infection and develop cervical cancer pointing to co- factors including host genetics that might play a role in outcome of the HPV infection. This study investigated the role of CCR2-V64I polymorphism in cervical cancer, pre-cancers and HPV infection in South African women resident in Western Cape. CCR2-V64I polymorphism has been previously reported to influence the progression to cervical cancer in some populations and has also been associated with decreased progression from HIV infection to AIDS.

Methods

Genotyping for CCR2-V64I was done by PCR-SSP in a case-control study of 446 women (106 black African and 340 mixed-ancestry) with histologically confirmed invasive cervical cancer and 1432 controls (322 black African and 1110 mixed-ancestry) group-matched (1:3) by age, ethnicity and domicile status. In the control women HPV was detected using the Digene Hybrid Capture II test and cervical disease was detected by cervical cytology.

Results

The CCR2-64I variant was significantly associated with cervical cancer when cases were compared to the control group (P = 0.001). Further analysis comparing selected groups within the controls showed that individuals with abnormal cytology and high grade squamous intraepitleial neoplasia (HSIL) did not have this association when compared to women with normal cytology. HPV infection also showed no association with CCR2-64I variant. Comparing SIL positive controls with the cases showed a significant association of CCR2-64I variant (P = 0.001) with cervical cancer.

Conclusions

This is the first study of the role of CCR2-V64I polymorphism in cervical cancer in an African population. Our results show that CCR2-64I variant is associated with the risk of cervical cancer but does not affect the susceptibility to HPV infection or HSIL in South African women of black and mixed-ancestry origin. This result implies that the role of CCR2 is important in invasive cancer of the cervix but not in HPV infection or in the development of pre-cancers.
'Imported risk' or 'health transition'? Smoking prevalence among ethnic German immigrants from the Former Soviet Union by duration of stay in Germany - analysis of microcensus data
Authors: Reiss Katharina , Spallek Jacob , Razum Oliver
Published: June 2010

Background

It can be assumed that resettlers (ethnic German immigrants from the Former Soviet Union) show similar smoking patterns as persons in their countries of origin at the time of migration. We analysed how the smoking prevalence among resettlers differs from that among the general population of Germany and whether the prevalence differs between groups with increasing duration of stay.

Methods

To estimate the smoking prevalence we used the scientific-use-file (n = 477,239) of the German 2005 microcensus, an annual census representing 1% of all German households. Participation in the microcensus is obligatory (unit-nonresponse <7%). We stratified the prevalence of smoking among resettlers and the comparison group (population of Germany without resettlers) by age, sex, educational level and duration of stay. In total, 14,373 (3% of the total) persons were identified as resettlers.

Results

Female resettlers with short duration of stay had a significantly lower smoking prevalence than women in the comparison group. With increasing duration of stay their smoking prevalence appears to converge to that of the comparison group (e.g.: high educational level, age group 25-44 years: short duration of stay 15%, long duration of stay 24%, comparison group 28%). In contrast, the smoking prevalence among male resettlers with short duration of stay was significantly higher than that among men in the comparison group, but also with a trend towards converging (e.g.: high educational level, age group 25-44 years: short duration of stay 44%, long duration of stay 35%, comparison group 36%). Except for female resettlers with short duration of stay, the participants with low educational level had on average a higher smoking prevalence than those with a high educational level.

Conclusions

This is the first study estimating the smoking prevalence among resettlers by duration of stay. The results support the hypothesis that resettlers brought different smoking habits from their countries of origin shortly after migration. The observed convergence of the smoking habits with increasing duration of stay is in line with the hypothesis of migration as 'health transition'. However, due to the cross-sectional design of the study, further research is needed to confirm these findings.
Expression of extracellular matrix metalloproteinase inducer (EMMPRIN) and its related extracellular matrix degrading enzymes in the endometrium during estrous cycle and early gestation in cattle
Authors: Mishra Birendra , Kizaki Keiichiro , Koshi Katsuo , Ushizawa Koichi , Takahashi Toru , Hosoe Misa , Sato Takashi , Ito Akira , Hashizume Kazuyoshi
Published: June 2010

Background

Extracellular matrix metalloproteinase inducer (EMMPRIN) regulates several biological functions involving the modulation of cell behaviors via cell-cell and cell-matrix interactions. According to its diverse functions, we hypothesized that EMMPRIN may play an important role in endometrial remodeling and establishment of pregnancy in cow.

Methods

In this study, endometrial tissues from the cyclic cows during before ovulation, after ovulation and middle of estrous cycle; and pregnant endometrial tissues from Day 19 to 35 of gestation have been used. Expression of mRNA was analyzed by RT-PCR, qPCR and in situ hybridization whereas protein expression by immunohistochemistry and western blot analysis.

Results

EMMPRIN mRNA was expressed in both cyclic and pregnant endometrium and significantly higher in the endometrium at Day 35 of gestation than the cyclic endometrium. In Western blot analysis, an approximately 65 kDa band was detected in the endometrium, and approximately 51 kDa in the cultured bovine epithelial cells and BT-1 cells, respectively. Both in situ hybridization and immunohistochemistry data showed that EMMPRIN was primarily expressed in luminal and glandular epithelium with strong staining on Day 19 conceptus. At Day 19 of gestation, expression of EMMPRIN mRNA on luminal epithelium was decreased than that observed at middle of estrous cycle, however, on Day 30 of gestation, slightly increased expression was found at the site of placentation. Expression of matrix metalloproteinase-2 (MMP-2) and MMP-14 mRNA were mainly detected in stroma and their expression also decreased at Day 19 of gestation however it was also expressed at the site of placentation at Day 30 of gestation as observed for EMMPRIN. Expression of MMP-1 or -9 mRNA was very low and was below the detection limit in the cyclic and pregnant endometrium.

Conclusion

EMMPRIN from the luminal epithelium may regulate the expression of stromal MMP-2 and -14 suggesting its crucial role in adhesion and fusion of embryo to luminal epithelium by directly itself through physiological tissues remodeling and developmental process, and/or stimulating MMPs to compensate endometrial functions.
Human uterine leiomyoma-derived fibroblasts stimulate uterine leiomyoma cell proliferation and collagen type I production, and activate RTKs and TGF beta receptor signaling in coculture
Authors: Moore Alicia B , Yu Linda , Swartz Carol D , Zheng Xaiolin , Wang Lu , Castro Lysandra , Kissling Grace E , Walmer David K , Robboy Stanley J , Dixon Darlene
Published: June 2010

Background

Uterine leiomyomas (fibroids) are benign smooth muscle tumors that often contain an excessive extracellular matrix (ECM). In the present study, we investigated the interactions between human uterine leiomyoma (UtLM) cells and uterine leiomyoma-derived fibroblasts (FB), and their importance in cell growth and ECM protein production using a coculture system.

Results

We found enhanced cell proliferation, and elevated levels of ECM collagen type I and insulin-like growth factor-binding protein-3 after coculturing. There was also increased secretion of vascular endothelial growth factor, epidermal growth factor, fibroblast growth factor-2, and platelet derived growth factor A and B in the media of UtLM cells cocultured with FB. Protein arrays revealed increased phosphorylated receptor tyrosine kinases (RTKs) of the above growth factor ligands, and immunoblots showed elevated levels of the RTK downstream effector, phospho-mitogen activated protein kinase 44/42 in cocultured UtLM cells. There was also increased secretion of transforming growth factor-beta 1 and 3, and immunoprecipitated transforming growth factor-beta receptor I from cocultured UtLM cells showed elevated phosphoserine expression. The downstream effectors phospho-small mothers against decapentaplegic -2 and -3 protein (SMAD) levels were also increased in cocultured UtLM cells. However, none of the above effects were seen in normal myometrial cells cocultured with FB. The soluble factors released by tumor-derived fibroblasts and/or UtLM cells, and activation of the growth factor receptors and their pathways stimulated the proliferation of UtLM cells and enhanced the production of ECM proteins.

Conclusions

These data support the importance of interactions between fibroid tumor cells and ECM fibroblasts in vivo, and the role of growth factors, and ECM proteins in the pathogenesis of uterine fibroids.
Hydrogen Sulphide Induces μ Opioid Receptor-Dependent Analgesia in a Rodent Model of Visceral Pain
Authors: Distrutti Eleonora , Cipriani Sabrina , Renga Barbara , Mencarelli Andrea , Migliorati Marco , Cianetti Stefano , Fiorucci Stefano
Published: June 2010

Background:

Hydrogen sulphide (H2S) is a gaseous neuro-mediator that exerts analgesic effects in rodent models of visceral pain by activating KATPchannels. A body of evidence support the notion that KATPchannels interact with endogenous opioids. Whether H2S-induced analgesia involves opioid receptors is unknown.

Methods:

The perception of painful sensation induced by colorectal distension (CRD) in conscious rats was measured by assessing the abdominal withdrawal reflex. The contribution of opioid receptors to H2S-induced analgesia was investigated by administering rats with selective μ, κ and δ opioid receptor antagonists and antisenses. To investigate whether H2S causes μ opioid receptor (MOR) transactivation, the neuronal like cells SKNMCs were challenged with H2S in the presence of MOR agonist (DAMGO) or antagonist (CTAP). MOR activation and phosphorylation, its association to β arrestin and internalization were measured.

Results:

H2S exerted a potent analgesic effects on CRD-induced pain. H2S-induced analgesia required the activation of the opioid system. By pharmacological and molecular analyses, a robust inhibition of H2S-induced analgesia was observed in response to central administration of CTAP and MOR antisense, while κ and δ receptors were less involved. H2S caused MOR transactivation and internalization in SKNMCs by a mechanism that required AKT phosphorylation. MOR transactivation was inhibited by LY294002, a PI3K inhibitor, and glibenclamide, a KATPchannels blocker.

Conclusions:

This study provides pharmacological and molecular evidence that antinociception exerted by H2S in a rodent model of visceral pain is modulated by the transactivation of MOR. This observation provides support for development of new pharmacological approaches to visceral pain.
Palatal tremor after lithium and carbamazepine use: a case report
Authors: Mahasuar Rajnarayan , Kuruvilla Anju , Jacob KS
Published: June 2010

Introduction

Palatal tremor, characterized by rhythmic contractions of the soft palate, can occur secondary to pathology in the dentato-rubro-olivary pathway, or in the absence of such structural lesions. Its pathogenesis is only partially understood. We describe a case of probable drug-induced palatal tremor.

Case presentation

A 27-year-old Indian man had taken carbamazepine and lithium for 7 years for the treatment of a manic episode. He presented with a one-year history of bilateral rhythmic oscillations of his soft palate and tremors of his tongue. There were no other abnormalities detected from his examination or after detailed investigation.

Conclusion

Palatal tremors may result from medication used in the treatment of psychiatric disorders.
Chromosome 16p11.2 deletions: another piece in the genetic puzzle of childhood obesity
Authors: Perrone Laura , Marzuillo Pierluigi , Grandone Anna , del Giudice Emanuele Miraglia
Published: June 2010

Ipercaloric diet and reduced physical activity have driven the rise in the prevalence of childhood obesity over a relatively short time interval. Family and twin studies have led to the conclusion that the strong predicitve value of parental body mass index (BMI) mainly stems from genetic rather than environmental factors. Whereas the common polygenic obesity arises when an individual genetic make-up is susceptible to an environment that promotes energy consumption over energy expenditure, monogenic obesity, on the contrary, is the obesity associated with a single gene mutation, which is sufficient by itself to cause weight gain in a food abundant context. Genes involved in the leptin-melanocortin pathway are often mutated in these cases. The cumulative prevalence of monogenic obesity among children with severe obesity is about 5%.

Recently, deletions in the region p11.2 of the chromosome 16 encompassing the gene SH2B1, which is involved in the leptin and insulin signaling, have been reported in about 0.5% of children with severe early-onset obesity. These patients show extreme hyperphagia, severe insulin resistance and, in some cases, mild developmental delay.
Prospectively measured triiodothyronine levels are positively associated with breast cancer risk in postmenopausal women
Authors: Tosovic Ada , Bondeson Anne-Greth , Bondeson Lennart , Ericsson Ulla-Britt , Malm Johan , Manjer Jonas
Published: June 2010

Introduction

The potential association between hypo- and hyperthyroid disorders and breast cancer has been investigated in a large number of studies during the last decades without conclusive results. This prospective cohort study investigated prediagnostic levels of thyrotropin (TSH) and triiodothyronine (T3) in relation to breast cancer incidence in pre- and postmenopausal women.

Methods

In the Malmö Preventive Project, 2,696 women had T3 and/or TSH levels measured at baseline. During a mean follow-up of 19.3 years, 173 incident breast cancer cases were retrieved using record linkage with The Swedish Cancer Registry. Quartile cut-points for T3 and TSH were based on the distribution among all women in the study cohort. A Cox's proportional hazards analysis was used to estimate relative risks (RR), with a confidence interval (CI) of 95%. Trends over quartiles of T3 and TSH were calculated considering a P-value < 0.05 as statistically significant. All analyses were repeated for pre- and peri/postmenopausal women separately.

Results

Overall there was a statistically significant association between T3 and breast cancer risk, the adjusted RR in the fourth quartile, as compared to the first, was 1.87 (1.12 to 3.14). In postmenopausal women the RRs for the second, third and fourth quartiles, as compared to the first, were 3.26 (0.96 to 11.1), 5.53 (1.65 to 18.6) and 6.87 (2.09 to 22.6), (P-trend: < 0.001). There were no such associations in pre-menopausal women, and no statistically significant interaction between T3 and menopausal status. Also, no statistically significant association was seen between serum TSH and breast cancer.

Conclusions

This is the first prospective study on T3 levels in relation to breast cancer risk. T3 levels in postmenopausal women were positively associated with the risk of breast cancer in a dose-response manner.
Chewing rates among domestic dog breeds
Authors: Gerstner Geoffrey E. , Cooper Meghan , Helvie Peter
Published: June 2010

The mammalian masticatory rhythm is produced by a brainstem timing network. The rhythm is relatively fixed within individual animals but scales allometrically with body mass (Mb) across species. It has been hypothesized that sensory feedback and feed-forward adjust the rhythm to match the jaw's natural resonance frequency, with allometric scaling being an observable consequence. However, studies performed with adult animals show that the rhythm is not affected by jaw mass manipulations, indicating that either developmental or evolutionary mechanisms are required for allometry to become manifest. The present study was performed to tease out the relative effects of development versus natural selection on chewing rate allometry. Thirty-one dog breeds and 31 mass-matched non-domestic mammalian species with a range in Mb from ∼2 kg to 50 kg were studied. Results demonstrated that the chewing rhythm did not scale with Mb among dog breeds (R=0.299, P>0.10) or with jaw length (Lj) (R=0.328, P>0.05). However, there was a significant relationship between the chewing rhythm and Mb among the non-domestic mammals (R=0.634, P<0.001). These results indicate that scaling is not necessary in the adult animal. We conclude that the central timing network and related sensorimotor systems may be necessary for rhythm generation but they do not explain the 1/3rd to 1/4th allometric scaling observed among adult mammals. The rhythm of the timing network is either adjusted to the physical parameters of the jaw system during early development only, is genetically determined independently of the jaw system or is uniquely hard-wired among dogs and laboratory rodents.
Cardiovascular performance of six species of field-acclimatized centrarchid sunfish during the parental care period
Authors: Cooke Steven J. , Schreer Jason F. , Wahl David H. , Philipp David P.
Published: June 2010

Parental care is an energetically costly period of the life history of many fish species characterized by extended high intensity activity. To date, there have been no studies that have investigated the cardiovascular correlates of extended parental care in fish. Using Doppler flow probes, the cardiovascular performance of six syntopic centrarchid fish species (N=232) that provide sole, male parental care was examined across a range of water temperatures that encompass their reproductive periods (14–26°C). Experiments were restricted to males but included both nesting and non-nesting individuals to evaluate the cardiovascular performance of fish during parental care. Resting values for cardiac output () and heart rate (fH) tended to be higher for nesting fish when adjusted for variation in temperature. Both of these cardiac variables also increased with water temperature. Stroke volume (VS) was similar among nesting and non-nesting fish and was generally thermally insensitive. When exposed to exhaustive exercise, nesting fish took longer to exhaust than non-nesting individuals. The high resting levels found in nesting fish accompanied by only minor increases in maximal values typically resulted in reductions in cardiac scope. Cardiovascular variables recovered more quickly in nesting fish, which could facilitate the high activity and bursting associated with parental care. Interspecifically, several cardiovascular variables were correlated with parental care activity. Parental care investment became more energetically expensive as the degree of cardiac frequency modulation decreased. Additionally, as the duration of parental care increased, so did the time required for fish to become exhausted, although this relationship was probably influenced by the fact that the larger species (e.g. smallmouth bass Micropterus dolomieu; largemouth bass Micropterus salmoides) provided the lengthiest care. Collectively, these data indicate that fish that provide parental care possess adaptations, including sufficient phenotypic plasticity, such that they can enhance their ability to provide high intensity protracted care, and emphasize the nexus between behavior and physiology.
Collision avoidance by running insects: antennal guidance in cockroaches
Authors: Baba Yoshichika , Tsukada Akira , Comer Christopher M.
Published: June 2010

Cockroaches were observed with videographic methods as escape running was initiated, but with obstacles in the path of their run. The goal was to determine the repertoire of possible responses to obstacles and the sensory cues used to trigger the responses. Intact cockroaches collided with obstacles on only about 10% of trials. The most common collision avoidance strategy was simply to stop running prior to impact. However, occasionally animals moved vertically and climbed over the barrier, or turned and navigated an edge of the obstacle, or completely reversed run direction. The avoidance strategies chosen depended on the size and configuration of the obstacle. Tests for the use of vision in detecting obstacles showed that its role, if any, is small. However, all manipulations that altered the antennal system changed behavior in a way consistent with the hypothesis that antennal mechanosensation plays a major role in collision avoidance. For example, reducing antennal length, or severing the main antennal nerve without altering the length produced significant increases in the frequency of collisions. Tests with tethered insects showed that (1) the antennae are preferentially directed forward as animals run, and (2) nearly simultaneous contact with both antennae is required to make the cockroach stop. Our data indicate that running cockroaches employ strategies that set their sensorimotor systems in a mode of readiness to deal with obstacles and they suggest that sensory information about the presence and configuration of obstacles is used to make choices, at very short latencies, about how to respond to obstructions.
The fish eye view: are cichlids conspicuous?
Authors: Dalton Brian E. , Cronin Thomas W. , Marshall N. Justin , Carleton Karen L.
Published: June 2010

The extent of animal colouration is determined by an interplay between natural and sexual selection. Both forces probably shape colouration in the speciose, rock-dwelling cichlids of Lake Malawi. Sexual selection is thought to drive male colouration, overcoming natural selection to create conspicuous colour patterns via female mate choice and male–male competition. However, natural selection should make female cichlids cryptic because they mouthbrood their young. We hypothesize that as a result of both sexual and natural selection, males will have colours that are more conspicuous than female colours. Cichlid spectral sensitivity, especially in the ultraviolet, probably influences how colours appear to them. Here we use simple models of the trichromatic colour space of cichlid visual systems to compare the conspicuousness of male and female nuptial colours of nine species. Conspicuousness of colours was evaluated as their Euclidian distance in colour space from environmental backgrounds and from other colours on the same fish. We find in six of the nine species that breeding males have colours that are statistically more conspicuous than female colours. These colours contrast strongly with each other or with the backgrounds, and they fall within a range of spectra best transmitted in the habitat. Female colour distances were sometimes smaller, suggesting that females of some species are more cryptic than males. Therefore, selection can differentially act to generate male colours that are more conspicuous than those in females. However, in two species, females had colours that were more conspicuous than male colours, suggesting that other selective forces and possibly sexual conflicts are acting in this system.
Inhibition of glutamine synthetase during ammonia exposure in rainbow trout indicates a high reserve capacity to prevent brain ammonia toxicity
Authors: Sanderson L. A. , Wright P. A. , Robinson J. W. , Ballantyne J. S. , Bernier N. J.
Published: June 2010

Glutamine synthetase (GSase), the enzyme that catalyses the conversion of glutamate and ammonia to glutamine, is present at high levels in vertebrate brain tissue and is thought to protect the brain from elevated ammonia concentrations. We tested the hypothesis that high brain GSase activity is critical in preventing accumulation of brain ammonia and glutamate during ammonia loading in the ammonia-intolerant rainbow trout. Trout pre-injected with saline or the GSase inhibitor methionine sulfoximine (MSOX, 6 mg kg–1), were exposed to 0, 670 or 1000 μmol l–1 NH4Cl in the water for 24 and 96 h. Brain ammonia levels were 3- to 6-fold higher in ammonia-exposed fish relative to control fish and MSOX treatment did not alter this. Brain GSase activity was unaffected by ammonia exposure, while MSOX inhibited GSase activity by ∼75%. Brain glutamate levels were lower and glutamine levels were higher in fish exposed to ammonia relative to controls. While MSOX treatment had little impact on brain glutamate, glutamine levels were significantly reduced by 96 h. With ammonia treatment, significant changes in the concentration of multiple other brain amino acids occurred and these changes were mostly reversed or eliminated with MSOX. Overall the changes in amino acid levels suggest that multiple enzymatic pathways can supply glutamate for the production of glutamine via GSase during ammonia exposure and that alternative transaminase pathways can be recruited for ammonia detoxification. Plasma cortisol levels increased 7- to 15-fold at 24 h in response to ammonia and MSOX did not exacerbate this stress response. These findings indicate that rainbow trout possess a relatively large reserve capacity for ammonia detoxification and for preventing glutamate accumulation during hyperammonaemic conditions.
Evidence for glutamate, GABA and NO in coordinating behaviour in the sponge, Ephydatia muelleri (Demospongiae, Spongillidae)
Authors: Elliott Glen R. D. , Leys Sally P.
Published: June 2010

The view that sponges lack tissue level organisation, epithelia, sensory cells and coordinated behaviour is challenged by recent molecular studies showing the existence in Porifera of molecules and proteins that define cell signalling systems in higher order metazoans. Demonstration that freshwater sponges can contract their canals in an organised manner in response to both external and endogenous stimuli prompted us to examine the physiology of the contraction behaviour. Using a combination of digital time-lapse microscopy, high-performance liquid chromatography–mass spectrometry (HPLC–MS) analysis, immunocytochemistry and pharmacological manipulations, we tested the role of the diffusible amino acids glutamate and γ-aminobutyric acid (GABA) and a short-lived diffusible gas, nitric oxide (NO), in triggering or modulating contractions in Ephydatia muelleri. We identified pools of glutamate, glutamine and GABA used to maintain a metabotropic glutamate and GABA receptor signalling system. Glutamate induced contractions and propagation of a stereotypical behaviour inflating and deflating the canal system, acting in a dose-dependent manner. Glutamate-triggered contractions were blocked by the metabatropic glutamate receptor inhibitor AP3 and by incubation of the sponge in an allosteric competitive inhibitor of glutamate, Kynurenic acid. Incubation in GABA inhibited glutamate-triggered contractions of the sponge. Nitric oxide synthase, involved in the formation of the diffusible gas NO, was localised using NADPH-diaphorase to mesenchyme cells in the osculum and pinacoderm. A cGMP assay showed the same cells were labelled suggesting that the NO system is functional. Our findings suggest sponges coordinate behaviour using chemical messenger systems common to other animals.
Snout allometry in seahorses: insights on optimisation of pivot feeding performance during ontogeny
Authors: Roos Gert , Van Wassenbergh Sam , Herrel Anthony , Adriaens Dominique , Aerts Peter
Published: June 2010

As juvenile life-history stages are subjected to strong selection, these stages often show levels of performance approaching those of adults, or show a disproportionately rapid increase of performance with age. Although testing performance capacity in aquatic suction feeders is often problematic, in pivot feeders such as seahorses models have been proposed to estimate whether snout length is optimal to minimise the time needed to reach the prey. Here, we investigate whether the same model can also explain the snout lengths in an ontogenetic series of seahorses, explore how pivot feeding kinematics change during ontogeny, and test whether juveniles show disproportionate levels of performance. Our analysis shows that the dimensions of the snout change during ontogeny from short and broad to long and narrow. Model calculations show that the snout lengths of newborn and juvenile seahorses are nearly optimal for minimising prey reach time. However, in juveniles the centre of head rotation in the earth-bound frame of reference is located near the posterior end of the head, whereas in adults it is shifted forward and is located approximately above the eye. Modelling shows that this forward shift in the centre of rotation has the advantage of decreasing the moment of inertia and the torque required to rotate the head, but has the disadvantage of slightly increasing the time needed to reach the prey. Thus, the snout lengths of juvenile seahorses appear to be close to optimal, suggesting that they reach levels of performance close to adult levels, which illustrates the pervasive nature of selection on performance in juveniles.
Oxidative stress and information content of black and yellow plumage coloration: an experiment with greenfinches
Authors: Hõrak Peeter , Sild Elin , Soomets Ursel , Sepp Tuul , Kilk Kalle
Published: June 2010

Carotenoid and melanin pigments in the plumage of birds are hypothesized to be sensitive to oxidative stress. We manipulated oxidative status of captive greenfinches (Carduelis chloris L.) by the administration of buthionine sulfoximine (BSO), a selective inhibitor of the synthesis of glutathione (GSH), an intracellular antioxidant. Half of the birds in the treated group, as well as in the control group, also received dietary carotenoid (lutein) supplementation. BSO treatment reduced erythrocyte GSH levels and caused oxidative damage as indicated by the increased concentration of plasma malondialdehyde (MDA), an end product of lipid peroxidation. BSO treatment also reduced the brightness (i.e. increased blackness) of the tips of tail feathers grown during the experiment. These results show that a low systemic GSH level is required for development of eumelanin plumage coloration and that such a low GSH level is also potentially dangerous for the organism. Carotenoid supplementation increased plasma carotenoid levels and chroma of the yellow parts of the feathers grown during the experiment. However, carotenoid supplementation did not reduce plasma MDA levels. Manipulation of GSH did not affect plasma carotenoids or carotenoid-based plumage coloration. These findings argue against the antioxidant function of lutein in vivo and carotenoid signaling of antioxidant status.
Asymmetry of different brain structures in homing pigeons with and without navigational experience
Authors: Mehlhorn Julia , Haastert Burkhard , Rehkämper Gerd
Published: June 2010

Homing pigeons (Columba livia f.d.) are well-known for their homing abilities, and their brains seem to be functionally adapted to homing as exemplified, e.g. by their larger hippocampi and olfactory bulbs. Their hippocampus size is influenced by navigational experience, and, as in other birds, functional specialisation of the left and right hemispheres (‘lateralisation’) occurs in homing pigeons. To show in what way lateralisation is reflected in brain structure volume, and whether some lateralisation or asymmetry in homing pigeons is caused by experience, we compared brains of homing pigeons with and without navigational experience referring to this. Fourteen homing pigeons were raised under identical constraints. After fledging, seven of them were allowed to fly around the loft and participated successfully in races. The other seven stayed permanently in the loft and thus did not share the navigational experiences of the first group. After reaching sexual maturity, all individuals were killed and morphometric analyses were carried out to measure the volumes of five basic brain parts and eight telencephalic brain parts. Measurements of telencephalic brain parts and optic tectum were done separately for the left and right hemispheres. The comparison of left/right quotients of both groups reveal that pigeons with navigational experience show a smaller left mesopallium in comparison with the right mesopallium and pigeons without navigational experience a larger left mesopallium in comparison with the right one. Additionally, there are significant differences between left and right brain subdivisions within the two pigeon groups, namely a larger left hyperpallium apicale in both pigeon groups and a larger right nidopallium, left hippocampus and right optic tectum in pigeons with navigational experience. Pigeons without navigational experience did not show more significant differences between their left and right brain subdivisions. The results of our study confirm that the brain of homing pigeons is an example for mosaic evolution and indicates that lateralisation is correlated with individual life history (experience) and not exclusively based on heritable traits.
Preparation of Aluminum Hydroxide and Alumina Particles in an Ionic Liquid
Authors: Kinoshita Keigo , Minami Hideto , Tarutani Yasunori , Okubo Masayoshi
Published: June 2010

Highly crystalline Al(OH)3 particles were successfully prepared by the sol–gel process of aluminum isopropoxide (Al(OPri)3) in a hydrophilic ionic liquid (IL), 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]) at 30 °C using NH4OH as catalyst. Moreover, crystalline alumina particles were prepared from the Al(OH)3 particles by heat treatment at 300 °C. When 2-propanol was used as medium for comparison, obtained particles were low crystalline AlO(OH). This difference seemed to arise from the difference in the local structure of Al(OPri)3 in IL.
Room-temperature Synthesis of CdMoO4 Nanooctahedra in the Hemline Length of 30 nm
Authors: Li Yanfen , Mi Yan , Jiang Junying , Huang Zaiyin
Published: June 2010

Uniform single-crystal CdMoO4 nanooctahedra in the hemline regime of 30 nm have been synthesized via a reverse-microemulsion route at room temperature. The as-prepared products were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). Room-temperature photoluminescence (PL) measurement exhibited a blue emission peaking at 438 nm under the 360 nm excitation, which is mainly attributed to the existence of intrinsic distortions into the [MoO4] tetrahedron moiety in the lattices.
Retrospectives: Say's Law
Authors: Baumol William J
Published: June 2010

What is perhaps most curious about ‘Say's law’ is the continuing disagreement on its substance and to whom it should be credited. John Maynard Keynes summarized the law as ‘supply creates its own demand’ but it is now generally agreed that Keynes did not get it quite right. The author has been unable to ascertain who coined the term ‘Say's law’ but it appears to be a twentieth century appellation, preceding Keynes's use. John-Baptiste Say was certainly among the earlier writers to discuss the topic at length but so far as the author can determine, none of Say's contemporaries--including Say himself--credits him with having been first to enunciate its principles.
The Structure of Foreign Trade
Authors: Helpman Elhanan
Published: June 2010

During the last two decades, new research has greatly advanced the understanding of the structure of world trade. While research in the 1960s and 1970s provided mostly theoretical insights, major empirical innovations concerning the study of factor content of net trade flows appeared in the 1980s. Important improvements in this line of research were added in the 1990s. The author also discusses the literature that emphasizes economies of scale and product differentiation. This work was done mostly in the 1980s and 1990s, yielding important theoretical and empirical findings. An emphasis on the interplay between theoretical and empirical research characterizes the entire presentation.
Retrospectives: American Economists in the Progressive Era on the Minimum Wage
Authors: Prasch Robert E
Published: June 2010

Beginning in 1912, a number of states passed minimum wage legislation that applied exclusively to women and minors. These tentative experiments in economic legislation ended in 1923 when the Supreme Court overturned the District of Columbia's minimum wage law. Remarkably, at this time virtually all professional American economists supported some variety of minimum wage legislation; however, they did not all give the same reasons. This paper briefly examines the context in which this minimum wage legislation was passed and then surveys several of the arguments that American economists gave in support of minimum wage laws.
Africa's Economic Performance: Limitations of the Current Consensus
Authors: Sender John
Published: June 2010

Historical and micro-survey evidence, as well as the standard data from international organizations, support less pessimistic conclusions on Africa's development performance than those reached by many social scientists. The changes that have benefited women over the last four decades are highlighted; a discussion of growth in agricultural production follows. However, the complexity and the brutality of processes of social and economic change in Sub-Saharan African economies are also stressed. The theoretical implications of these complexities have not been adequately analyzed by World Bank economists. The Bank's recent efforts to reassess its policies are, therefore, unlikely to achieve the results anticipated.
Teaching Problem Solving Techniques to MBA Students Through Supply Chain Management
Authors: Fry Michael J.
Published: June 2010

This paper describes the use of a supply chain management course to teach problem solving techniques to MBA students. An introduction to problem solving techniques and a step-by-step methodology are presented that can be used in supply chain management courses. We discuss two specific supply chain management cases and provide examples of how these cases can be used to illustrate steps in the problem solving methodology. We also describe how problem solving skills can be reinforced and assessed through case study write-ups. We conclude with some feedback from students who have taken this class.
Teaching Note—Some Practical Issues with Excel Solver: Lessons for Students and Instructors
Authors: Evans James R.
Published: June 2010

Spreadsheets have become the principal software application for teaching decision models in most business schools. In particular, Excel Solver is used extensively for solving and analyzing optimization models. However, there are a number of important issues in using Solver of which many users are unaware. These include the impact of spreadsheet design and cell formatting on Solver reports, handling of lower and upper bound constraints, and dealing with the implications of implicit assumptions in spreadsheet models when interpreting Solver sensitivity reports. Students and instructors, as well as most popular textbooks, rarely pay sufficient attention to these issues. This article summarizes these important issues, provides guidelines for avoiding problems, and offers examples that can be incorporated into the classroom.
Managerial Communication of Analytical Work
Authors: Grossman Thomas A. , Norback Judith Shaul , Hardin Jill R. , Forehand Garlie A.
Published: June 2010

When business and management science students graduate and have a job, they give many managerial communications about analytical work, but typically they are not taught how to give presentations in their undergraduate courses. We describe the characteristics of the “managerial presentation” and contrast them with characteristics of the “narrative presentation” that is given to technical peers and focuses on process. We then use the business analysis lifecycle to describe and contrast the real world and the model world. Implications for instruction build upon empirical data gathered at Georgia Tech for the presentation skills identified through interviews with engineers, managers, and senior executives in the workforce. We conclude by reviewing processes already used effectively for teaching the relevant presentation skills at Georgia Tech.
Teaching Note—Teaching Project Simulation in Excel Using PERT-Beta Distributions
Authors: Davis Ron
Published: June 2010

This paper presents the methodology for computing the correct general formulas for the PERT-beta distribution, and how they are used to carry out stochastic project duration simulations using the built-in tools available in Excel. A comparison with results obtained using the Excel add-ins Crystal Ball, @Risk, RiskSolver, and PopTools is included. Slightly different parameterizations are used by each application, so various forms of the formulas are shown for each case.
Spreadsheet Modeling of the G/G/c Queuing System without Macros or Add-Ins
Authors: Hora Stephen C.
Published: June 2010

Spreadsheets are have become a popular tool for teaching business students about waiting line systems. Modeling queuing systems with multiple servers, however, is somewhat difficult and ordinarily accomplished by using macros or by having multiple templates, each template with a different number of servers. Here, it is shown how native Excel array functions can be used to create a spreadsheet model with the number of servers being an adjustable parameter.
OR/MS Games: 4. The Joy of Egg-Dropping in Braunschweig and Hong Kong
Authors: Sniedovich Moshe
Published: June 2010

In this discussion we examine the famous 2-egg puzzle from an OR/MS perspective and explore the structure of the optimal policies for this puzzle. It is shown that the puzzle provides a vivid environment for teaching/learning basic concepts related to decision making under uncertainty, including the differences and similarities between the Worst Case and Expected Value scenarios. The more general problem where N test eggs-rather than 2- are provided is also examined. A number of interactive modules for experimenting with and solving this interesting puzzle are provided. Lecturers teaching dynamic programming (DP) might be interested in using this puzzle to illustrate how DP works and how it can be used to derived closed-form solutions to discrete optimization problems. A reference is provided to a practical real world application of the mathematical model used to analyze and solve the game.
Daily Play at A Golf Course: Using Spreadsheet Simulation to Identify System Constraints
Authors: Tiger Andrew A. , Salzer Dave
Published: June 2010

We present a spreadsheet-based simulation model of daily play at a golf course and how it can be used in teaching. The model represents the variability and interactions that impact pace of play on a golf course as measured by throughput (rounds played) and cycle time (round length). The model predicts that most of the waiting time will occur on par 3 tee boxes. Alleviating this bottleneck by allowing the following group on par 3 holes to tee off while the group ahead is walking to the green, was shown to improve throughput by 13% without increasing cycle time. The model was developed using MS-Excel and @RISK, a Monte Carlo simulation package.
On Modeling Line Balancing Problems in Spreadsheets
Authors: Ragsdale Cliff T. , Brown Evelyn C.
Published: June 2010

Ragsdale (2003) recently introduced an innovative approach to implementing project management networks in spreadsheets that greatly simplifies the handling of precedence relations among activities. This paper demonstrates how a similar technique can be used to create efficient spreadsheet models for line balancing problems.
A Translation Approach To Teaching Linear Program Formulation
Authors: Stevens Scott P. , Palocsay Susan W.
Published: June 2010

While there have been many improvements in the teaching of operations research/management science (OR/MS) in recent years, students continue to have great difficulty with the process of constructing a linear programming model. We propose addressing this issue with a translation approach that breaks the process down into a series of small, well-defined steps. The underlying idea is to develop a representation of the problem in terms of measurable quantities that can then be translated, via application of an explicit rule, into the proper algebraic form and/or equivalent spreadsheet formulas. As background, related research on word problem solving from cognitive psychology and mathematical education is reviewed in the paper. We illustrate the translation approach with several examples and explain how using it can improve students' modeling skills. Preliminary data on the effectiveness of the methodology for undergraduate business students in an introductory MS course is also presented.
Teaching Statistics with Sports Examples
Authors: Kvam Paul H. , Sokol Joel
Published: June 2010

Class material for introductory and advanced statistics can be colorfully illustrated by using appropriate data and examples from sports. Specific methods, including statistical graphics (e.g., boxplots), ball-and-urn probabilities, and statistical regression are demonstrated. Examples are drawn from popular American sports such as baseball, basketball, soccer, and American football. Classroom feedback indicates that that most students enjoy sports examples as a way to learn abstract concepts using familiar, recreational settings.
The Pooling Principle
Authors: Cattani Kyle , Schmidt Glen M.
Published: June 2010

A key insight of basic inventory models and of the G/G/m queueing model is the effect of “pooling.” That is, these models suggest that pooling of customer demands, along with pooling of the resources used to fill those demands, may yield operational improvements. While there are many research papers that articulate and quantify the benefits of pooling, a review of popular texts in operations management suggests that most texts lack simple examples that illustrate this important concept. This note is intended to fill this void by articulating the “pooling principle” in an intuitive, straightforward fashion. This note is comprised of a brief instructor's note, followed by a note that can be included in a course pack or handed out to students. Earlier versions of the note have been used successfully in core operations courses at both the undergraduate business and MBA levels.
Using Multimedia to Facilitate Software Instruction in an Introductory Modeling Course
Authors: Hardin Jill R. , Ellington Aimee J.
Published: June 2010

Multimedia tutorials were developed to introduce basic software functions to students in an introductory operations research modeling course. The purpose of these tutorials was to reduce the amount of class time spent addressing deficiencies in software mastery and allow for more class time to focus on modeling concepts. The motivation for developing these tools and details on the design of the tutorials are outlined. We conducted a quasi-experimental pre-test/post-test assessment of the value of the tutorials. The results of the formal assessment as well as student reactions and anecdotal evidence of their usefulness are discussed. We conclude with an evaluation of lessons learned in the process and encourage other educators to consider a similar approach.