bluuebunny/crossref_metadata_2025 huggingface dataset:
Absence of Mutagenicity, Genotoxicity, and Subchronic Oral Toxicity of Touchi Extract
Authors: Fujita Hiroyuki , Yamagami Tomohide
Published: October 2007

Touchi, a traditional Chinese food used mainly for seasoning is obtained by first steaming soybeans followed by fermentation with Aspergillus oryzae (koji). A series of toxicological studies was conducted to evaluate the mutagenic and genotoxic potential and subchronic toxicity of a water extract of Touchi, a known inhibitor of α-glucosidase activity. Touchi extract (TE) did not induce reverse mutations in Salmonella typhimurium strains TA98, TA1537, TA100, TA1535, and Escherichia coli WP2uvrA at concentrations up to 5000 μg/plate, in either the absence or presence of exogenous metabolic activation. No deaths occurred and no abnormal clinical signs were observed in any animal in any group in an in vivo micronucleus test, and TE was devoid of clastogenic activity when administered orally to mice at doses up to 2000 mg/kg/day. Thus, TE was evaluated as negative in the bacterial reverse mutation and mouse bone marrow micronucleus tests under the conditions of these assays. To evaluate its subchronic toxicity, SPF rats were administered TE at doses of 0,250,1000, and 2500 mg/kg/day via oral gastric intubation. No treatment-related toxic changes were seen in clinical signs, body weight, food consumption, urinalysis, hematology, blood chemistry, necropsy, organ weight, or histopathology. The no observed adverse effect level for TE was thus considered to be more than 2500 mg/kg/day in both males and females. These results are consistent with Touchi’s status as a traditional Chinese food derived from fermented soybeans and its purported long history of use. Specifically, these data are consistent with the expected safety of human consumption of TE up to at least 5 g/day.
Evaluating Complementary Therapies for Canine Osteoarthritis—Part II: A Homeopathic Combination Preparation (Zeel®)
Authors: Hielm-Björkman Anna , Tulamo Riitta-Mari , Salonen Hanna , Raekallio Marja
Published: October 2007

A homeopathic combination preparation (HCP) for canine osteoarthritic pain was evaluated in a randomized, double‐controlled and double‐blinded clinical trial. Forty‐four dogs with osteoarthritis (OA) that were randomly allocated into one of three groups completed the study. All dogs were fed test products or placebo for 8 weeks. The dogs were evaluated at the clinic four times, with 4‐week intervals. Six different variables were assessed: veterinary‐assessed mobility, two force plate variables, an owner‐evaluated chronic pain index and pain and locomotion visual analogue scales (VASs). Intake of extra non‐steroidal anti‐inflammatory drugs was also evaluated. A Chi‐squared test and a Mann–Whitney test were used to determine significant improvement between groups. When changed into dichotomous responses of ‘improved’ or ‘not improved’ three out of the six variables showed a significant difference (P = 0.016, P = 0.008, P = 0.039) in improved dogs per group, between the HCP group and the placebo group. The odds ratios were over one for the same variables. As extent of improvement in the variables from start to end of treatment, the HCP product was significantly more improved in four (P = 0.015, P = 0.028, P = 0.049, P = 0.020) of the six variables, compared with the placebo. Our results indicated that the HCP Zeel® was beneficial in alleviating chronic orthopedic pain in dogs although it was not as effective as carprofen.
Scope and utility of hydrogen exchange as a tool for mapping landscapes
Authors: Jaswal Sheila S. , Miranker Andrew D.
Published: October 2007

The ability to determine conformational parameters of protein‐folding landscapes is critical for understanding the link between conformation, function, and disease. Monitoring hydrogen exchange (HX) of labile protons at equilibrium enables direct extraction of thermodynamic or kinetic landscape parameters in two limiting extremes. Here, we establish a quantitative framework for relating HX behavior to landscape. We use this framework to demonstrate that the range of predicted global HX behavior for the majority of a set of characterized two‐state proteins under near‐native conditions does not readily span between both extremes. For most, stability may be quantitatively determined under physiological conditions, with semiquantitative boundaries on kinetics additionally determined using modest experimental perturbations to shift HX behavior. The framework and relationships derived in the simple context of two‐state global folding highlight the importance of understanding HX across the entire continuum of behavior, in order to apply HX to map landscapes.
Case–control study on cigarette smoking and the risk of hepatocellular carcinoma among Japanese
Authors: Hara Megumi , Tanaka Keitaro , Sakamoto Tatsuhiko , Higaki Yasuki , Mizuta Toshihiko , Eguchi Yuichiro , Yasutake Tsutomu , Ozaki Iwata , Yamamoto Kyosuke , Onohara Shingo , Kawazoe Seiji , Shigematsu Hirohisa , Koizumi Shunzo
Published: October 2007

Emerging epidemiologic data suggest that cigarette smoking may increase the risk of hepatocellular carcinoma (HCC), yet considerable controversies (e.g. inconsistent dose–response relationships) still exist with this association. We examined whether smoking was associated with HCC risk in a case–control study including 209 incident HCC cases and two different control groups (256 hospital controls and 381 patients with chronic liver disease [CLD] without HCC). Comparison of HCC cases with CLD patients, but not with hospital controls, demonstrated a significantly increased risk of HCC for current smokers. After adjustment for sex, age, heavy drinking history and hepatitis virus markers, odds ratios (and 95% confidence intervals) for former and current smokers relative to never smokers were 1.0 (0.6–1.7) and 2.5 (1.4–4.6), respectively, against CLD patients, as compared with 0.8 (0.3–2.3) and 1.8 (0.6–5.1), respectively, against hospital controls. In terms of pack‐years during lifetime, dose–response relationship was not evident against either control group (P trend = 0.43), but it became clearer for more recent cigarette use among CLD patients. For example, regarding cumulative cigarette consumption during the last 5 years, adjusted odds ratios (and 95% confidence intervals) for 1–4 and 5+ pack‐years relative to no use were 1.9 (1.1–3.6) and 2.8 (1.5–5.2) (P trend = 0.003), respectively. These results suggest that cigarette smoking may play a crucial role in the late stage of HCC development and that CLD patients may benefit from their earliest smoking cessation. (Cancer Sci 2008; 99: 93–97)
Apoptotic pathway induced by transduction of RUNX3 in the human gastric carcinoma cell line MKN‐1
Authors: Nagahama Yumi , Ishimaru Mika , Osaki Mitsuhiko , Inoue Toshiaki , Maeda Akihiro , Nakada Chisato , Moriyama Masatsugu , Sato Kenzo , Oshimura Mitsuo , Ito Hisao
Published: October 2007

The human runt‐related transcription factor 3 gene (RUNX3) is considered to be a candidate tumor suppressor gene in gastric carcinoma. However, the role of RUNX3 in the regulation of cell proliferation remains unclear. In the present study, we constructed an adenoviral vector encoding human RUNX3 cDNA under the control of a Tet‐responsive promoter (Ad‐Tet‐FLAG‐RUNX3), which regulates the expression of RUNX3 in the presence or absence of doxycycline. A recombinant adenoviral expression vector encoding LacZ (Ad‐Tet‐LacZ) was used as a negative control. The effect of the transduction of RUNX3 on cell growth was examined using the Tet‐On system in a human gastric carcinoma cell line, MKN‐1. Exogenous RUNX3 expression was induced successfully by Ad‐Tet‐FLAG‐RUNX3, but not Ad‐Tet‐LacZ, in the presence of doxycycline in the MKN‐1 cells. At 72 h after infection, the proliferative activity in RUNX3‐expressing cells was 55% or less of that of the control cells. Flow cytometry revealed that the sub‐G1 peak was increased in cells expressing RUNX3 (34.11%), indicating that the inhibition of cell growth was due to apoptosis, which was confirmed based on Hoechst 33258 staining, the release of cytochrome c from mitochondria into the cytosol, and detection of cleaved caspase‐3 by western blotting in MKN‐1 cells. Comprehensive analysis using a cDNA microarray showed that RUNX3 upregulated 17 apoptosis‐related genes (including FADD, TRAF6, caspase‐2, ING1, ING4, Calpain 10, and DNase1) and downregulated 135 apoptosis‐related genes (including FLIP, PEA15, TXN2, HSPD1, IKK, and TIAL1) in MKN‐1 cells. Pathway analyses to generate functional networks of the genes suggested that promotion of the formation of the death‐inducing signaling complex and activation of the mitochondria‐mediated pathway were associated with RUNX3‐induced apoptosis. In conclusion, our findings suggest that exogenous RUNX3 expression suppressed cell proliferation by inducing apoptosis via the death‐receptor mitochondria‐mediated pathway in MKN‐1 cells. (Cancer Sci 2008; 99: 23–30)
Latitudinal gradients in niche breadth: empirical evidence from haematophagous ectoparasites
Authors: Krasnov Boris R. , Shenbrot Georgy I. , Khokhlova Irina S. , Mouillot David , Poulin Robert
Published: October 2007

Aim We searched for relationships between latitude and both the geographic range size and host specificity of fleas parasitic on small mammals. This provided a test for the hypothesis that specialization is lower, and thus niche breadth is wider, in high‐latitude species than in their counterparts at lower latitudes.

Location We used data on the host specificity and geographic range size of 120 Palaearctic flea species (Siphonaptera) parasitic on small mammals (Soricomorpha, Lagomorpha and Rodentia). Data on host specificity were taken from 33 regions, whereas data on geographic ranges covered the entire distribution of the 120 species.

Methods Our analyses controlled for the potentially confounding effects of phylogenetic relationships among flea species by means of the independent‐contrasts method. We used regressions and structural equation modelling to determine whether the latitudinal position of the geographic range of a flea covaried with either the size of its range or its host specificity. The latter was measured as the number of host species used, as well as by an index providing the average (and variance in) taxonomic distinctness among the host species used by a flea.

Results Geographic range size was positively correlated with the position of the centre of the range; in other words, fleas with more northerly distributions had larger geographic ranges. Although the number of host species used by a flea did not vary with latitude, both the mean taxonomic distinctness among host species used and its variance increased significantly towards higher latitudes.

Main conclusions The results indicate that niche breadth in fleas, measured in terms of both its spatial (geographic range size) and biological (host specificity) components, increases at higher latitudes. These findings are compatible with the predictions of recent hypotheses about latitudinal gradients.
Embryo Production in Superovulated Goats Treated with Insulin Before or After Mating or By Continuous Propylene Glycol Supplementation
Authors: Souza AL , Galeati G , Almeida AP , Arruda IJ , Govoni N , Freitas VJF , Rondina D
Published: October 2007

Contents

Seventeen adult and cyclic Moxoto goats were synchronized using 60 mg MPA vaginal sponge for 11 days and 50 μg cloprostenol, 48 h before sponge removal, and superovulated with 120 mg pFSH i.m. in decreasing doses at 12 h intervals for three consecutive days. In seven goats, 0.2 IU/kg BW/day of long acting insulin was subcutaneously injected at same time as pFSH, and in the other five goats, the same dose of insulin was injected for three consecutive days starting 24 h after mating. Finally, five goats were supplemented with an oral dose of 80 ml/goat/day of propylene glycol continuously during the experiment. The animals were flushed at 7 days after mating and the embryos were classified based on International Embryo Transfer Society criteria. Blood samples were collected every 3 days for insulin assay. Administration of insulin raised the insulin levels of the goats (p < 0.05), whereas in the group treated with propylene glycol, insulin rate was different only between FSH treatment and after mating (p < 0.05). Similar rates of recovery for total (80.05 ± 9.78%) or transferable structures (61.03 ± 15.13%) were obtained. Treatment was not influenced (p > 0.05) by responsiveness to superovulation, which averaged 64%. By contrast, insulin treatments were shown to increase the number of embryos considered excellent with respect to goats supplemented with propylene glycol (p < 0.05). When insulin was given before mating, a strong relationship (r = 0. 90) (p < 0.05) between number of transferable embryo and ovulations was observed in the animals. In conclusion, superovulated goats treated with low doses of exogenous insulin resulted in an enhancement in embryo quality, which was related to changes in circulating insulin concentrations.
Systematic review of the use of financial incentives in treatments for obesity and overweight
Authors: Paul‐Ebhohimhen V. , Avenell A.
Published: October 2007

Nine studies met the criteria for inclusion in this systematic review of randomized controlled trials of treatments for obesity and overweight involving the use of financial incentives, with reported follow‐up of at least 1 year. All included trials were of behavioural obesity treatments. Justification of sample size and blinding procedure were not mentioned in any study. Attrition was well described in three studies and no study was analysed on an intention to treat basis. Participants were mostly women recruited through media advertisements. Mean age ranged from 35.7 to 52.8 years, and mean body mass index from 29.3 to 31.8 kg m−2. Results from meta‐analysis showed no significant effect of use of financial incentives on weight loss or maintenance at 12 months and 18 months. Further sub‐analysis by mode of delivery and amount of incentives although also non‐statistically significant were suggestive of very weak trends in favour of use of amounts greater than 1.2% personal disposable income, rewards for behaviour change rather than for weight, rewards based on group performance rather than for individual performance and rewards delivered by non‐psychologists rather than delivered by psychologists.
Cross‐sectional Tests of Conditional Asset Pricing Models: Evidence from the German Stock Market
Authors: Schrimpf Andreas , Schröder Michael , Stehle Richard
Published: October 2007

We study the performance of conditional asset pricing models and multifactor models in explaining the German cross‐section of stock returns. We focus on several variables, which (according to previous research) are associated with market expectations on future market excess returns or business cycle conditions. Our results suggest that the empirical performance of the Capital Asset Pricing Model (CAPM) can be improved when allowing for time‐varying parameters of the stochastic discount factor. A conditional CAPM using the term spread explains the returns on our size and book‐to‐market sorted portfolios about as well as the Fama‐French three‐factor model and performs best in terms of the Hansen‐Jagannathan distance. Structural break tests do not necessarily indicate parameter instability of conditional model specifications. Another major finding of the paper is that the Fama‐French model – despite its generally good cross‐sectional performance – is subject to model instability. Unconditional models, however, do a better job than conditional ones at capturing time‐series predictability of the test portfolio returns.
Efficacy of panoramic radiographs in the preoperative planning of posterior mandibular implants: a prospective clinical study of 1527 consecutively treated patients
Authors: Vazquez Lydia , Saulacic Nikola , Belser Urs , Bernard Jean‐Pierre
Published: October 2007

Objectives: Various imaging techniques, including conventional radiography and computed tomography, are proposed to localize the mandibular canal prior to implant surgery. The aim of this study is to determine the incidence of altered mental nerve sensation after implant placement in the posterior segment of the mandible when a panoramic radiograph is the only preoperative imaging technique used.

Material and methods: The study included 1527 partially and totally edentulous patients who had consecutively received 2584 implants in the posterior segment of the mandible. Preoperative bone height was evaluated from the top of the alveolar crest to the superior border of the mandibular canal on a standard panoramic radiograph. A graduated implant scale from the implant manufacturer was used and 2 mm were subtracted as a safety margin to determine the length of the implant to be inserted.

Results: No permanent sensory disturbances of the inferior alveolar nerve were observed. There were two cases of postoperative paresthesia, representing 2/2584 (0.08%) of implants inserted in the posterior segment of the mandible or 2/1527 (0.13%) of patients. These sensory disturbances were minor, lasted for 3 and 6 weeks and resolved spontaneously.

Conclusions: Panoramic examination can be considered a safe preoperative evaluation procedure for routine posterior mandibular implant placement. Panoramic radiography is a quick, simple, low‐cost and low‐dose presurgical diagnostic tool. When a safety margin of at least 2 mm above the mandibular canal is respected, panoramic radiography appears to be sufficient to evaluate available bone height prior to insertion of posterior mandibular implants; cross‐sectional imaging techniques may not be necessary.
Radiographic changes in alveolar bone height on overdenture abutments: a longitudinal study
Authors: Brkovic‐Popovic Snezana , Stanisic‐Sinobad Darinka , Postic Srdjan D. , Djukanovic Dragoslav
Published: October 2007

Objective:  Stabilisation of partial dentures is an important part of prosthodontic treatment, particularly in patients with an excessive reduction in alveolar bone supporting their abutment teeth. In these cases, overdenture prostheses are one possible treatment choice.

Background:  The aim of this study was to evaluate the effects of overdentures on the condition of alveolar bone of the remaining teeth, and to evaluate the overdenture concept in the prosthetic treatment of partially edentulous patients.

Materials and methods:  The investigation was conducted on 22 patients during observation periods of 6 and 10 years. After preparation, all abutment teeth were provided with either amalgam restorations or gold copings. An overdenture in the lower jaw was fabricated for every patient. A special film holder was used to repeat the X‐ray procedure in every patient in the same manner. The radiographs were evaluated using the grid scale. The alveolar bone level of all remaining teeth was evaluated on dental films by measuring the distance between the root apex and coronal border of the alveolar bone.

Results:  A statistically significant difference (p < 0.01) was calculated 6 years after delivery stage between distal alveolar bone levels of experimental abutments under overdentures and the remaining teeth of the control group. Alveolar bone of abutment teeth was considerably preserved, particularly in seven patients observed 10 years after provision of their dentures.

Conclusion:  Within the limitation of this study, the validity of the overdenture treatment in partially edentulous patients is concluded. Good oral hygiene was crucial for the success of treatment with overdentures.
Suggesting the use of integrated methods for vole population management in alfalfa fields
Authors: HAIM Abraham , SHANAS Uri , BRANDES Ora , GILBOA Abraham
Published: October 2007

Human‐made agro‐ecosystems lack negative feedback controls, which may result in rodent population explosions, causing considerable economic loss and thus increasing human‐wildlife conflicts. The traditional solution is the extensive use of rodenticides, which have a negative impact on the environment. In Beit‐Sheaan Valley, Israel, which is located on a major route for migrating birds, poisoning of voles may result in the death of birds that prey on the dead voles (e.g. storks and herons). In the present essay we discuss some integrated methods, based on the implementation of ecological principles in agro‐ecosystems, that could be used to decrease the use of rodenticides. The first method is light interference during winter (long scotophase), which can result in the death of the social vole Microtus socialis kept in enclosures under natural conditions. Under laboratory conditions such interference causes a decrease in thermoregulatory ability in the cold. As light interference is a source of pollution, only active vole burrows should be illuminated. The second method involves using the mobile irrigation pipelines to flood the vole burrows and force them to escape into the open, where diurnal birds such as storks and herons will prey on them. The third method involves the use of nesting boxes for barn owls and stands for diurnal raptors, both of which prey on voles. The great advantage of using an integrated approach is that voles cannot become adapted to any one of the methods. Such integrated methods, together with appropriate treatment of alfalfa fields by farmers, can provide an efficient and sustainable pest control approach.
Relationship between increase rate of human plague in China and global climate index as revealed by cross‐spectral and cross‐wavelet analyses
Authors: ZHANG Zhibin , LI Zhenqing , TAO Yi , CHEN Min , WEN Xinyu , XU Lei , TIAN Huidong , STENSETH Nils Chr.
Published: October 2007

Plague has caused the death of hundreds of millions of people throughout the human history. Today this disease is again re‐emerging and hence is again becoming an increasing threat to human health in several parts of the world. However, impacts of global climate variation (e.g. El Nino and Southern Oscillation [ENSO]) and global warming on plagues are largely unknown. Using cross‐spectral analysis and cross‐wavelet analysis, we have analyzed the relationship between increase rate of human plague in China during 1871–2003 and the following climate factors (as measured by the Southern Oscillation Index [SOI], Sea Surface Temperature of east Pacific equator [SST] and air Temperature of the Northern Hemisphere [NHT]). We found in the frequency domain that increase rate of human plague was closely associated with SOI and SST. Cross‐spectral analysis reveals that significant coherencies between increase rate of human plague and ENSO were found over short periods (2‐3 years), medium periods (6‐7 years) and long periods (11‐12 years, 30–40 years). Cross‐wavelet analysis reveals that increase rate of human plague oscillates in phase with SOI, but in anti‐phase with SST over periods of 2–4 years and approximately 8 years (6‐10 years). These results indicate that ENSO‐driven climate variation may be important for occurrences of human plague in China. However, there is a need for a further analysis of the underlying mechanism between human plague in China and ENSO.
Factors related to the occurrence of hybrids between brown haresLepus europaeusand mountain haresL. timidusin Sweden
Authors: Jansson Gunnar , Thulin Carl‐Gustaf , Pehrson Åke
Published: October 2007

Hybridization occurs among many species, and may have implications for conservation as well as for evolution. Interspecific gene flow between brown haresLepus europaeusand mountain haresL. timidushas been documented in Sweden and in continental Europe, and has probably to some extent occurred throughout history in sympatric areas. What local factors or ecological relationships that correlate with or trigger hybridization between these species has however been unclear. We studied spatial distribution of hybrids between brown hares and mountain hares in Sweden in relation to characteristics of the sampled localities (hunting grounds). In a sample of 70 brown hares collected from 39 populations in south‐central Sweden during 2003–2005, 11 (16%) showed introgressed mtDNA from mountain hares. Among the brown hares from their northern range, i.e. in general the most recent establishments, the corresponding figure was 75% (9/12). The frequency of samples with hybrid ancestry increased significantly with latitude, altitude and hilliness, and were higher (p<0.1) in recently established populations and/or where the proportion of arable land was low. Several site‐specific parameters were correlated, e.g. latitude as expected to hilliness, and no parameter explained the occurrence of hybrids exclusively. Instead, the appearance of mountain hare mtDNA among brown hares was associated with a conglomerate of parameters reflecting landscapes atypical for the brown hare, e.g. forest dominated and steep areas where the species quite recently was established. We suggest that these abiotic factors mirror the main aspect influencing hybridization frequency, namely the density or relative frequency of the two species. In atypical brown hare landscapes with recent establishment, mountain hares are probably relatively more common. When one species dominate in numbers, or when both species display low densities, increased frequency of hybridization is expected due to low availability of conspecific partners, a phenomenon referred to as Hubbs’ principle.
How do vigilance and feeding by common cranesGrus grusdepend on age, habitat, and flock size?
Authors: Avilés Jesús M. , Bednekoff Peter A.
Published: October 2007

Animals often spend less time vigilant and more time feeding when foraging in larger groups. This group‐size effect does not, however, consider if larger groups differ systematically from smaller ones: Large groups could form in different habitats than small groups or be composed of a different mix of ages or classes than small groups. We examined how habitat differences and flock size and composition explain feeding and vigilance rates in common cranesGrus grus, wintering in holm oakQuercus ilexdehesas of Spain. Flock size and composition were related to habitat type in cranes: flocks formed in areas sown with cereal crops were larger than flocks formed in set aside areas. Vigilance rate depended on habitat but decreased with increasing flock size in a similar way across all habitats. Juveniles were less vigilant than adults and showed little change in vigilance with flock size. Vigilance increased and feeding time decreased over months from November through February. Our results show that vigilance is affected by habitat but that the group size effect on vigilance is not the product of differences between habitats in group size or composition.
Melanin, carotenoid and structural plumage ornaments: information content and role in great tits Parus major
Authors: Hegyi Gergely , Szigeti Beáta , Török János , Eens Marcel
Published: October 2007

The importance of plumage colour as an indicator of individual quality and the basis of sexual selection has long been recognized. Of the three generally distinguished classes of plumage colours, melanin‐based ornaments are traditionally considered to provide less reliable information than carotenoid‐based traits. However, the role of structural ornaments in multiple signalling systems has rarely been examined, and no study has compared the information content and role of the three ornament types simultaneously. Here we investigated three plumage ornaments in great tits Parus major: the size of the melanin‐based breast stripe, the carotenoid‐based colour of the yellow breast and the structurally based reflectance properties of the black crown. We worked on both the mechanistic and the functional levels. First, we assessed the dependence of ornaments on body condition during moult using ptilochronology. Second, we estimated assortative mating for these traits, as a measure of mutual sexual selection. Only the spectral attributes of crown feathers correlated with body condition during moult. However, breast stripe size was related to age, while the brightness of the yellow breast indicated body size. Relative crown ultraviolet reflectance was much higher in males than in females. Assortative mating was strongest for crown ultraviolet reflectance, but composite measures suggest that a system of multiple sexually selected traits with different information content may work in this population. These data support the accumulating evidence that the condition‐dependence of melanin and carotenoid coloration is not qualitatively different. They also suggest that more research should target the reflectance properties of dark plumage areas in general, and ultraviolet crown ornamentation in tits in particular.
Cautious response of inexperienced birds to conventional signal of stronger threat
Authors: S. Osiejuk Tomasz , Łosak Katarzyna , Dale Svein
Published: October 2007

Several studies demonstrated that bird song functions as a first line of territorial defence. The efficiency of deterring rivals depends strongly on the strategy of singing used (e.g. alternating/overlapping singing, singing with low/high rate, matching song type of a rival or singing different type). Causes of between males variation during countersinging are still not fully understood, especially when different signals have similar production costs and their meaning is assigned by arbitrary convention (conventional signalling). We tested whether an oscine bird with small repertoire size, the ortolan bunting Emberiza hortulana, differentiate strategy of responding to song of an intruder in relation to its age and threat value of signals. We performed playback experiments to measure response of second year (SY) and after second year (ASY) males to a song of low (eventual variety singing) and high (immediate variety singing) threat value. We found substantial differences in response to playback, which were related both to the type of stimuli used and age of responding males. Both SY and ASY males gave more calls than songs in response to immediate variety playback, which suggest stronger vocal response to the signal of higher threat value. Approaching loudspeaker was similar for both age classes when lower threat value signal was played back, while simultaneously SY males clearly avoided approaching loudspeaker when stronger threat values signal was played back. We conclude that ortolan bunting differentiate response to signal of different threat value and that the strength of response depends on the age of a male. This study provides experimental evidence that age of receiver affects its response to a territorial intruder. It also demonstrates that observed in many studies variation in response to playback may be an effect of age differences between males, which rarely is controlled.
GABAA‐receptor modification in taurine transporter knockout mice causes striatal disinhibition
Authors: Sergeeva O. A. , Fleischer W. , Chepkova A. N. , Warskulat U. , Häussinger D. , Siebler M. , Haas H. L.
Published: October 2007

The Striatum is involved in the regulation of movements and motor skills. We have shown previously, that the osmolyte and neuromodulator taurine plays a role in striatal plasticity. We demonstrate now that hereditary taurine deficiency in taurine‐transporter knock‐out (TAUT KO) mice results in disinhibition of striatal network activity, which can be corrected by taurine supplementation. Modification of GABAA but not glycine receptors (taurine is a ligand for both receptor types) underlies this disinhibition. Whole‐cell recordings from acutely isolated as well as cultured striatal neurons revealed a decreased agonist sensitivity of the GABAA receptor in TAUT KO neurons in the absence of changes in the maximal GABA‐evoked current amplitude. The striatal GABA level in TAUT KO mice was unchanged. The amplitude enhancement of spontaneous IPSCs by zolpidem was stronger in TAUT KO than in wild‐type (WT) animals. Tonic inhibition was absent in striatal neurons under control conditions but was detected after incubation with the GABA‐transaminase inhibitor vigabatrin: bicuculline induced a larger shift of baseline current in WT as compared to TAUT KO neurons. Lack of taurine leads to reduced sensitivity of synaptic and extrasynaptic GABAA receptors and consequently to disinhibition. These findings help in understanding neuropathologies accompanied by the loss of endogenous taurine, for instance in hepatic encephalopathy.
The role of oxygen in prenatal growth: studies in the chick embryo
Authors: Giussani Dino A. , Salinas Carlos E. , Villena Mercedes , Blanco Carlos E.
Published: October 2007

The compelling evidence linking small size at birth with later cardiovascular disease has renewed and amplified scientific and clinical interests into the determinants of fetal growth. It is accepted that genes and nutrition control fetal growth; however, prior to this study, it had been impossible to isolate the effect of increases and decreases in fetal oxygenation on the regulation of prenatal growth. We investigated the role of oxygen in the control of fetal growth in the chicken because in contrast to mammals, the effects on the fetus of changes in oxygenation could be isolated, by assessing them directly without alteration to the maternal or placental physiology or maternal nutrition during development. The data show that incubation at high altitude of fertilized eggs laid by sea level hens markedly restricted fetal growth. Incubation at high altitude of fertilized eggs laid by high altitude hens also restricted fetal growth, but to a lesser extent compared to eggs laid by sea level hens. By contrast, incubation at sea level of fertilized eggs laid by high altitude hens not only restored, but enhanced, fetal growth relative to sea level controls. Incubation at high altitude of sea level eggs with oxygen supplementation completely prevented the high altitude‐induced fetal growth restriction. Thus, fetal oxygenation, independent of maternal nutrition during development, has a predominant role in the control of fetal growth. Further, prolonged high altitude residence confers protection against the deleterious effects of hypoxia on fetal growth.
Astrocytes play a critical role in transient heterosynaptic depression in the rat hippocampal CA1 region
Authors: Andersson My , Blomstrand Fredrik , Hanse Eric
Published: October 2007

Active synapses can reduce the probability of transmitter release at neighbouring synapses. Depending on whether such heterosynaptic depression is mediated by intersynaptic diffusion of transmitter or by release of gliotransmitters, astrocytes should either hinder or promote the heterosynaptic depression. In the present study we have examined the developmental profile and astrocytic involvement in a transient heterosynaptic depression (tHeSD) in the CA1 region of the rat hippocampal slice preparation. A short stimulus burst (3 impulses at 50 Hz) to one group of synapses elicited a depression of the field EPSP evoked in another group of synapses that amounted to about 25% 0.5 s after the conditioning burst. This tHeSD was associated with an increase in the paired‐pulse ratio of about 30%. The tHeSD was not present in slices from rats younger than 10 postnatal days and developed towards the adult magnitude between postnatal days 10 and 20. The tHeSD was totally prevented by the glia‐specific toxin fluoroacetate (FAC), by carbenoxolone, a general blocker of connexin‐based channels, and by endothelin, an endogenous peptide that has been shown to block astrocytic connexin‐based channels. Antagonists to GABAB receptors and group II/III metabotropic glutamate receptors (mGluRs) abolished the tHeSD whereas antagonists to NMDA‐ and adenosine A1 receptors, and to group I mGluRs, did not affect the tHeSD. These results suggest that the tHeSD relies on GABAB receptors, group II/III mGluRs and on gliotransmitter release from functionally mature astrocytes.
Absence of humoral mediated 5′AMP‐activated protein kinase activation in human skeletal muscle and adipose tissue during exercise
Authors: Kristensen Jonas Møller , Johnsen Anders Bo , Birk Jesper B. , Nielsen Jakob Nis , Jensen Bente Rona , Hellsten Ylva , Richter Erik A. , Wojtaszewski Jørgen F. P.
Published: October 2007

5′AMP‐activated protein kinase (AMPK) exists as a heterotrimer comprising a catalytic α subunit and regulatory β and γ subunits. The AMPK system is activated under conditions of cellular stress, indicated by an increase in the AMP/ATP ratio, as observed, e.g. in muscles during contractile activity. AMPK was originally thought to be activated only by local intracellular mechanisms. However, recently it has become apparent that AMPK in mammals is also regulated by humoral substances, e.g. catecholamines. We studied whether humoral factors released during exercise regulate AMPK activity in contracting and resting muscles as well as in abdominal subcutaneous adipose tissue in humans. In resting leg muscle and adipose tissue the AMPK activity was not up‐regulated by humoral factors during one‐legged knee extensor exercise even when arm cranking exercise, inducing a ∼20‐fold increase in plasma catecholamine level, was added simultaneously. In exercising leg muscle the AMPK activity was increased by one‐legged knee extensor exercise eliciting a whole body respiratory load of only 30% but was not further increased by adding arm cranking exercise. In conclusion, during exercise with combined leg kicking and arm cranking, the AMPK activity in human skeletal muscle is restricted to contracting muscle without influence of marked increased catecholamine levels. Also, with this type of exercise the catecholamines or other humoral factors do not seem to be physiological regulators of AMPK in the subcutaneous adipose tissue.
Modulation of glycine potency in rat recombinant NMDA receptors containing chimeric NR2A/2D subunits expressed inXenopus laevisoocytes
Authors: Chen Philip E. , Geballe Matthew T. , Katz Elyse , Erreger Kevin , Livesey Matthew R. , O'Toole Kate K. , Le Phuong , Lee C. Justin , Snyder James P. , Traynelis Stephen F. , Wyllie David J. A.
Published: October 2007

Heteromeric NMDARs are composed of coagonist glycine‐binding NR1 subunits and glutamate‐binding NR2 subunits. The majority of functional NMDARs in the mammalian central nervous system (CNS) contain two NR1 subunits and two NR2 subunits of which there are four types (A–D). We show that the potency of a variety of endogenous and synthetic glycine‐site coagonists varies between recombinant NMDARs such that the highest potency is seen at NR2D‐containing and the lowest at NR2A‐containing NMDARs. This heterogeneity is specified by the particular NR2 subunit within the NMDAR complex since the glycine‐binding NR1 subunit is common to all NMDARs investigated. To identify the molecular determinants responsible for this heterogeneity, we generated chimeric NR2A/2D subunits where we exchanged the S1 and S2 regions that form the ligand‐binding domains and coexpressed these with NR1 subunits inXenopus laevisoocytes. Glycine concentration–response curves for NMDARs containing NR2A subunits including the NR2D S1 region gave mean glycine EC50values similar to NR2A(WT)‐containing NMDARs. However, receptors containing NR2A subunits including the NR2D S2 region or both NR2D S1 and S2 regions gave glycine potencies similar to those seen in NR2D(WT)‐containing NMDARs. In particular, two residues in the S2 region of the NR2A subunit (Lys719 and Tyr735) when mutated to the corresponding residues found in the NR2D subunit influence glycine potency. We conclude that the variation in glycine potency is caused by interactions between the NR1 and NR2 ligand‐binding domains that occur following agonist binding and which may be involved in the initial conformation changes that determine channel gating.
Cajal–Retzius cells in the mouse neocortex receive two types of pre‐ and postsynaptically distinct GABAergic inputs
Authors: Kirmse Knut , Dvorzhak Anton , Henneberger Christian , Grantyn Rosemarie , Kirischuk Sergei
Published: October 2007

Cajal–Retzius (CR) cells are principal cells of layer I in the developing neocortex. They are able to generate action potentials, make synaptic contacts in layer I and receive excitatory GABAergic inputs before birth. Although CR cells participate in neuronal network activity in layer I, the properties of their synaptic inputs are not yet characterized. We recorded miniature (mIPSCs) and evoked (eIPSCs) postsynaptic currents using the whole‐cell patch‐clamp technique. Most of CR cells displayed two types of mIPSCs, namely those with fast (mIPSCF) and slow (mIPSCS) rise kinetics. The mIPSCF mean amplitude was significantly larger than that of mIPSCS, while their decay rates were not different. Peak‐scaled non‐stationary noise analysis revealed that mIPSCS and mIPSCF differed in their weighted single‐channel conductance. In addition, zolpidem (100 nm), a modulator of α1 subunit‐containing GABAA receptors, selectively affected mIPSCS suggesting that different postsynaptic GABAA receptors mediate mIPSCF and mIPSCS. eIPSCs also split into two populations with different rise kinetics. Fast eIPSCs (eIPSCF) displayed higher paired‐pulse ratio (PPR) and lower GABA release probability than slowly rising eIPSCs (eIPSCS). As CGP55845, a GABAB receptor antagonist, eliminated the observed difference in PPR, the lower release probability at IPSCF connections probably reflects a stronger tonic GABAB receptor‐mediated inhibition of IPSCF synapses. At low (0.1 Hz) stimulation frequency both inputs can effectively convert presynaptic action potentials into postsynaptic ones; however, only IPSCF connections reliably transfer the presynaptic activity patterns at higher stimulation rates. Thus, CR cells receive two GABAergic inputs, which differ in the quantal amplitude, the probability of GABA release and the frequency dependence of signal transfer.
Experimental and Numerical Investigation of Structural Damage Detection Using Changes in Natural Frequencies
Authors: Xu G. Y. , Zhu W. D. , Emory B. H.
Published: October 2007

A robust iterative algorithm is used to identify the locations and extent of damage in beams using only the changes in their first several natural frequencies. The algorithm, which combines a first-order, multiple-parameter perturbation method and the generalized inverse method, is tested extensively through experimental and numerical means on cantilever beams with different damage scenarios. If the damage is located at a position within 0–35% or 50–95% of the length of the beam from the cantilevered end, while the resulting system equations are severely underdetermined, the minimum norm solution from the generalized inverse method can lead to a solution that closely represents the desired solution at the end of iterations when the stiffness parameters of the undamaged structure are used as the initial stiffness parameters. If the damage is located at a position within 35–50% of the length of the beam from the cantilevered end, the resulting solution by using the stiffness parameters of the undamaged structure as the initial stiffness parameters deviates significantly from the desired solution. In this case, a new method is developed to enrich the measurement information by modifying the structure in a controlled manner and using the first several measured natural frequencies of the modified structure. A new method using singular value decomposition is also developed to handle the ill-conditioned system equations that occur in the experimental investigation by using the measured natural frequencies of the modified structure.
Social Decision-Making: Insights from Game Theory and Neuroscience
Authors: Sanfey Alan G.
Published: October 2007

By combining the models and tasks of Game Theory with modern psychological and neuroscientific methods, the neuroeconomic approach to the study of social decision-making has the potential to extend our knowledge of brain mechanisms involved in social decisions and to advance theoretical models of how we make decisions in a rich, interactive environment. Research has already begun to illustrate how social exchange can act directly on the brain's reward system, how affective factors play an important role in bargaining and competitive games, and how the ability to assess another's intentions is related to strategic play. These findings provide a fruitful starting point for improved models of social decision-making, informed by the formal mathematical approach of economics and constrained by known neural mechanisms.
Decision-Making Dysfunctions in Psychiatry—Altered Homeostatic Processing?
Authors: Paulus Martin P.
Published: October 2007

Decision-making consists of selecting an action from a set of available options. This results in an outcome that changes the state of the decision-maker. Therefore, decision-making is part of a homeostatic process. Individuals with psychiatric disorders show altered decision-making. They select options that are either non-optimal or nonhomeostatic. These dysfunctional patterns of decision-making in individuals with psychiatric disorders may fundamentally relate to problems with homeostatic regulation. These may manifest themselves in (i) how the length of time between decisions and their outcomes influences subsequent decision-making, (ii) how gain and loss feedback are integrated to determine the optimal decision, (iii) how individuals adapt their decision strategies to match the specific context, or (iv) how seemingly maladaptive responses result from an attempt to establish an unstable homeostatic balance.
Outward Transport of High-Temperature Materials Around the Midplane of the Solar Nebula
Authors: Ciesla Fred J.
Published: October 2007

The Stardust samples collected from Comet 81P/Wild 2 indicate that large-scale mixing occurred in the solar nebula, carrying materials from the hot inner regions to cooler environments far from the Sun. Similar transport has been inferred from telescopic observations of protoplanetary disks around young stars. Models for protoplanetary disks, however, have difficulty explaining the observed levels of transport. Here I report the results of a new two-dimensional model that shows that outward transport of high-temperature materials in protoplanetary disks is a natural outcome of disk formation and evolution. This outward transport occurs around the midplane of the disk.
A Synthetic Lectin Analog for Biomimetic Disaccharide Recognition
Authors: Ferrand Yann , Crump Matthew P. , Davis Anthony P.
Published: October 2007

Carbohydrate recognition is biologically important but intrinsically challenging, for both nature and host-guest chemists. Saccharides are complex, subtly variable, and camouflaged by hydroxyl groups that hinder discrimination between substrate and water. We have developed a rational strategy for the biomimetic recognition of carbohydrates with all-equatorial stereochemistry (β-glucose, analogs, and homologs) and have now applied it to disaccharides such as cellobiose. Our synthetic receptor showed good affinities, not unlike those of some lectins (carbohydrate-binding proteins). Binding was demonstrated by nuclear magnetic resonance, induced circular dichroism, fluorescence spectroscopy, and calorimetry, all methods giving self-consistent results. Selectivity for the target substrates was exceptional; minor changes to disaccharide structure (for instance, cellobiose to lactose) caused almost complete suppression of complex formation.
Relativists, Skepticism, and Waves
Authors: Gordin Michael D.
Published: October 2007

Traveling at the Speed of Thought
. Einstein and the Quest for Gravitational Waves.
By Daniel Kennefick
. Princeton University Press, Princeton, NJ, 2007. 333 pp. $35, £19.95. ISBN 9780691117270.

The author's exploration of the evolution of the controversies surrounding gravitational waves illuminates the ways analogical reasoning works in science.