bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative system identification of flower tracking performance in three hawkmoth species reveals adaptations for dim light vision
Authors: Stöckl Anna L. , Kihlström Klara , Chandler Steven , Sponberg Simon
Published: February 2017

Flight control in insects is heavily dependent on vision. Thus, in dim light, the decreased reliability of visual signal detection also prompts consequences for insect flight. We have an emerging understanding of the neural mechanisms that different species employ to adapt the visual system to low light. However, much less explored are comparative analyses of how low light affects the flight behaviour of insect species, and the corresponding links between physiological adaptations and behaviour. We investigated whether the flower tracking behaviour of three hawkmoth species with different diel activity patterns revealed luminance-dependent adaptations, using a system identification approach. We found clear luminance-dependent differences in flower tracking in all three species, which were explained by a simple luminance-dependent delay model, which generalized across species. We discuss physiological and anatomical explanations for the variance in tracking responses, which could not be explained by such simple models. Differences between species could not be explained by the simple delay model. However, in several cases, they could be explained through the addition on a second model parameter, a simple scaling term, that captures the responsiveness of each species to flower movements. Thus, we demonstrate here that much of the variance in the luminance-dependent flower tracking responses of hawkmoths with different diel activity patterns can be captured by simple models of neural processing.

This article is part of the themed issue ‘Vision in dim light’.
Stellar performance: mechanisms underlying Milky Way orientation in dung beetles
Authors: Foster James J. , el Jundi Basil , Smolka Jochen , Khaldy Lana , Nilsson Dan-Eric , Byrne Marcus J. , Dacke Marie
Published: February 2017

Nocturnal dung beetles (Scarabaeus satyrus) are currently the only animals that have been demonstrated to use the Milky Way for reliable orientation. In this study, we tested the capacity ofS. satyrusto orient under a range of artificial celestial cues, and compared the properties of these cues with images of the Milky Way simulated for a beetle's visual system. We find that the mechanism that permits accurate stellar orientation under the Milky Way is based on an intensity comparison between different regions of the Milky Way. We determined the beetles' contrast sensitivity for this task in behavioural experiments in the laboratory, and found that the resulting threshold of 13% is sufficient to detect the contrast between the southern and northern arms of the Milky Way under natural conditions. This mechanism should be effective under extremely dim conditions and on nights when the Milky Way forms a near symmetrical band that crosses the zenith. These findings are discussed in the context of studies of stellar orientation in migratory birds and itinerant seals.

This article is part of the themed issue ‘Vision in dim light’.
Can model-free reinforcement learning operate over information stored in working-memory?
Authors: da Silva Carolina Feher , Yao Yuan-Wei , Hare Todd A.
Published: February 2017

Model-free learning creates stimulus-response associations. But what constitutes a stimulus? Are there limits to types of stimuli a model-free or habitual system can operate over? Most experiments on reward learning in humans and animals have used discrete sensory stimuli, but there is no algorithmic reason that model-free learning should be restricted to external stimuli, and recent theories have suggested that model-free processes may operate over highly abstract concepts and goals. Our study aimed to determine whether model-free learning processes can operate over environmental states defined by information held in working memory. Specifically, we tested whether or not humans can learn explicit temporal patterns of individually uninformative cues in a model-free manner. We compared the data from human participants in a reward learning paradigm using (1) a simultaneous symbol presentation condition or (2) a sequential symbol presentation condition, wherein the same visual stimuli were presented simultaneously or as a temporal sequence that required working memory. We found a significant effect of reward on human behavior in the sequential presentation condition, indicating that model-free learning can operate on information stored in working memory. Further analyses, however, revealed that the behavior of the participants contradicts the basic assumptions of our hypotheses, and it is possible that the observed effect of reward was generated by model-based rather than model-free learning. Thus it is not possible to draw any conclusions from out study regarding model-free learning of temporal sequences held in working memory. We conclude instead that careful thought should be given about how to best explain two-stage tasks to participants.
VICTOR: Genome-based Phylogeny and Classification of Prokaryotic Viruses
Authors: Meier-Kolthof Jan P. , Göker Markus
Published: February 2017

Bacterial and archaeal viruses (“phages”) play an enormous role in global life cycles and have recently regained importance as therapeutic agents to fight serious infections by multi-resistant bacterial strains. Nevertheless, taxonomic classification of phages is up to now only insufficiently informed by genome sequencing. Despite thousands of publicly available phage genomes, it still needs to be investigated how this wealth of information can be used for the fast, universal and accurate classification of phages. The Genome BLAST Distance Phylogeny (GBDP) approach is a truly whole-genome method currently used forin silicoDNA: DNA hybridization and phylogenetic inference from prokaryotic genomes. Based on the principles of phylogenetic systematics, we here established GBDP for phage phylogeny and classification, using the common subset of genome-sequenced and officially classified phages. Trees inferred with the best GBDP variants showed only few deviations from the official phage classification, which were uniformly due to incorrectly annotated GenBank entries. Except for low resolution at the family level, the majority of taxa was well supported as monophyletic. Clustering genome sequences with distance thresholds optimized for the agreement with the classification turned out to be phylogenetically reasonable. Accordingly modifying genera and species is taxonomically optional but would yield more uniform sequence divergence as well as stronger branch support. Analysing an expanded data set containing > 4000 phage genomes from public databases allowed for extrapolating regarding the number, composition and host specificity of future phage taxa. The selected methods are implemented in an easy-to-use web service “VICTOR” freely available athttp://ggdc.dsmz.de/victor.php.
Inferring decoding strategies for multiple correlated neural populations
Authors: Lakshminarasimhan Kaushik J , Pouget Alexandre , DeAngelis Gregory C , Angelaki Dora E , Pitkow Xaq
Published: February 2017

Studies of neuron-behaviour correlation and causal manipulation have long been used separately to understand the neural basis of perception. Yet these approaches sometimes lead to drastically conflicting conclusions about the functional role of brain areas. Theories that focus only on choice-related neuronal activity cannot reconcile those findings without additional experiments involving large-scale recordings to measure interneuronal correlations. By expanding current theories of neural coding and incorporating results from inactivation experiments, we demonstrate here that it is possible to infer decoding weights of different brain areas without precise knowledge of the correlation structure. We apply this technique to neural data collected from two different cortical areas in macaque monkeys trained to perform a heading discrimination task. We identify two opposing decoding schemes, each consistent with data depending on the nature of correlated noise. Our theory makes specific testable predictions to distinguish these scenarios experimentally without requiring measurement of the underlying noise correlations.

Author Summary

The neocortex is structurally organized into distinct brain areas. The role of specific brain areas in sensory perception is typically studied using two kinds of laboratory experiments: those that measure correlations between neural activity and reported percepts, and those that inactivate a brain region and measure the resulting changes in percepts. The two types of experiments have generally been interpreted in isolation, in part because no theory has been able combine their outcomes. Here, we describe a mathematical framework that synthesizes both kinds of results, giving us a new way to assess how different brain areas contribute to perception. When we apply our framework to experiments on behaving monkeys, we discover two models that can explain the perplexing finding that one brain area can predict an animal’s percepts, even though the percepts are not affected when that brain area is inactivated. The two models ascribe dramatically different efficiencies to brain computation. We show that these two models can be distinguished by an experiment that measures correlations while inactivating different brain areas.
Uncharacterized bacterial structures revealed by electron cryotomography
Authors: Dobro Megan J. , Oikonomou Catherine M. , Piper Aidan , Cohen John , Guo Kylie , Jensen Taylor , Tadayon Jahan , Donermeyer Joseph , Park Yeram , Solis Benjamin A. , Kjær Andreas , Jewett Andrew I. , McDowall Alasdair W. , Chen Songye , Chang Yi-Wei , Shi Jian , Subramanian Poorna , Iancu Cristina V. , Li Zhuo , Briegel Ariane , Tocheva Elitza I. , Pilhofer Martin , Jensen Grant J.
Published: February 2017

SUMMARY STATEMENT

Here we present a survey of previously uncharacterized structures we have observed in bacterial cells by electron cryotomography, in the hopes of spurring their identification and study.

Electron cryotomography (ECT) can reveal the native structure and arrangement of macromolecular complexes inside intact cells. This technique has greatly advanced our understanding of the ultrastructure of bacterial cells. Rather than undifferentiated bags of enzymes, we now view bacteria as structurally complex assemblies of macromolecular machines. To date, our group has applied ECT to nearly 90 different bacterial species, collecting more than 15,000 cryotomograms. In addition to known structures, we have observed several, to our knowledge, uncharacterized features in these tomograms. Some are completely novel structures; others expand the features or species range of known structure types. Here we present a survey of these uncharacterized bacterial structures in the hopes of accelerating their identification and study, and furthering our understanding of the structural complexity of bacterial cells.
Crystal structure of the solid solution Ba8.35Pb0.65(B3O6)6
Authors: Zhao Wenwu
Published: February 2017

Single crystals of lead barium borate, Ba8.35Pb0.65(B3O6)6, octabarium lead(II) hexakis(triborate), have been obtained by spontaneous nucleation from a high-temperature melt. Its three-dimensional structure is constructed on the basis of a BaO9polyhedron, a (Pb/Ba)O6octahedron (occupancy ratio Pb:Ba = 0.216:0.784) and a condensed B3O6ring anion. In the crystal, the planar B3O6anions are stacked in an alternating fashion with Ba and (Pb/Ba) atoms along [001]. A comparison is made with the structures of related solid solutions in the system Ba/Pb/B/O.
Crystal structure and hydrogen-bonding patterns in 5-fluorocytosinium picrate
Authors: Mohana Marimuthu , Thomas Muthiah Packianathan , McMillen Colin D.
Published: February 2017

In the crystal structure of the title compound, 5-fluorocytosinium picrate, C4H5FN3O+·C6H2N3O7−, one N heteroatom of the 5-fluorocytosine (5FC) ring is protonated. The 5FC ring forms a dihedral angle of 19.97 (11)° with the ring of the picrate (PA−) anion. In the crystal, the 5FC+cation interacts with the PA−anion through three-centre N—H...O hydrogen bonds, forming two conjoined rings havingR21(6) andR12(6) motifs, and is extended by N—H...O hydrogen bonds and C—H...O interactions into a two-dimensional sheet structure lying parallel to (001). Also present in the crystal structure are weak C—F...π interactions.
(E)-2-({[3-Benzylsulfanyl-5-(p-tolyl)-4H-1,2,4-triazol-4-yl]imino}methyl)phenol
Authors: Hou Qian , Li Lu , Wang Hewen
Published: February 2017

In the title compound, C23H20N4OS, the 1,2,4-triazole ring (r.m.s. deviation = 0.014 Å) forms dihedral angles of 88.66 (8), 24.48 (8) and 17.97 (7)° with the benzyl,p-tolyl and phenol rings, respectively. The conformation about the C=N bond isE. In the crystal, molecules are linked by O—H...N hydrogen bonds, forming chains along [010].
(2E,2′E)-1,1′-(1,4-Phenylene)bis[3-(3-chlorophenyl)prop-2-en-1-one]
Authors: Rajendraprasad S. , Chidan Kumar C. S. , Chandraju S. , Lokanath N. K. , Quah Ching Kheng , Naveen S. , Abdoh Muneer
Published: February 2017

The title bis-chalcone compound, C24H16Cl2O2, crystallizes with one half-molecule in the asymmetric unit. The molecule has crystallographic inversion symmetry and lies about an inversion centre at the centroid of the central benzene ring. The olefinic double bonds adoptEconfigurations. Thes-transconformation of the central C—C bond of the enone group is confirmed by a C—C—C=C torsion angle of −162.88 (17)°.
Predisposition towards foreign brands and materialism: a quantitative assessment
Authors: Vohra Aastha Verma , Gupta Garima
Published: February 2017

Purpose

The purpose of this paper is to identify the dimensions of predisposition towards foreign brands (PTFB) for Indian consumers and examine their impact on materialism/materialist value (MAT). The study further conducts an in-depth analysis of these constructs for possible variations across consumer demographics.

Design/methodology/approach

Using a structured questionnaire, primary data were collected from 487 respondents in the city of Delhi and National Capital Region (NCR). While a modified scale was developed to operationalize PTFB, the measurement instrument for MAT was adapted on the basis of an extensive literature review. Statistical techniques such as Exploratory factor analysis, Confirmatory factor analysis, t-test, analysis of variance (ANOVA) and regression analysis were used to test various hypotheses of the study.

Findings

The study identified five dimensions of PTFB, namely, “Reputation”, “Preference”, “Country of Origin”, “Accessibility” and “Quality”, through confirmatory factor analysis in structural equation modelling. Except for “Preference” and “Accessibility”, all remaining dimensions were found to be exerting a significant impact on MAT. The results further indicate that consumers’ PTFB as well as their MAT differs across demographics such as age, income, gender, occupation and qualification.

Practical implications

The paper brings to the fore useful insights for marketers of foreign brands. The findings can be effectively used for developing a more focused marketing strategy for Indian consumers by helping in identifying demographic segments that are more responsive and susceptible to the entry of foreign brands in Indian markets.

Originality/value

The paper attempts to develop a more robust instrument for measurement of consumers’ PTFB and provides dimensions constituting the construct for consumers of emerging markets such as India. The current research also indicates that there exists a significant variation in PTFB and MAT for different demographic segments of consumers.
Patient satisfaction and brand loyalty in health-care organizations in India
Authors: Sharma Vinay
Published: February 2017

Purpose

This paper aims to examine the major factors affecting patients’ satisfaction and loyalty at a health-care organization in India.

Design/methodology/approach

A conceptual model has been developed that includes the behavioural dimensions of total quality management (TQM), patient satisfaction and loyalty. This study is exploratory in nature and has used the existing literature to build the conceptual model.

Findings

A solution for improving the quality of health-care services can be found in the application of total relationship management and TQM, together with a customer orientation strategy.

Practical implications

The results can be used creatively by hospitals to re-engineer and redesign their quality management processes and reorient the future directions of their more effective health-care quality strategies.

Originality/value

In this research, a study is described involving a new instrument and a new method which assure a reasonable level of relevance, validity and reliability, while being explicitly change-oriented.
Financial distress and highway infrastructure delays
Authors: Edwards David John , Owusu-Manu De-Graft , Baiden Bernard , Badu Edward , Love Peter Edward
Published: February 2017

Purpose

In developing countries, delays in highway infrastructure projects caused by financial distress-related factors threaten the construction industry’s capacity to contribute optimally to economic development. Against this backdrop, this paper aims to determine factors contributing to financial distress and develops a conceptual framework to illustrate the relationship between financial distress and project delay.

Design/methodology/approach

A questionnaire survey collected data on factors that contributed to financial distress and delays in highway infrastructure delivery. In total, 78 responses were obtained, and factor analysis revealed that factors associated with payment, project financing, cash flow, economic issues, project planning and cost control influenced project delays.

Findings

The research identifies the importance of efficient public and private policies to engender financial sustainability among construction firms in developing countries.

Originality/value

This work presents the first research of its kind and strives to engender wider academic debate and renewed economic development in some of the world’s most impoverished nations.
Factors affecting the performance of private party in concession-based PPP projects in Nigeria
Authors: Opawole Akintayo , Jagboro Godwin Onajite
Published: February 2017

Purpose

Notwithstanding the remarkable market potential of the Nigerian economy for private investment, the current sociopolitical characteristics had necessitated a careful assessment to inform decisions in long-term investments. The purpose of this paper is therefore to evaluate the success factors that have a specific influence on private party’s performance in concession contracts in Nigeria.

Design/methodology/approach

Respondents involved in the study were participants in concession-based contracts in Southwestern Nigeria that included architects, estate surveyors, quantity surveyors, engineers and builders, accountants/bankers/economists and lawyers. These were selected using random and respondent-driven sampling (RDS) approaches. The research instrument adopted was a questionnaire that enlisted questions which were structured to ensure that the respondents have appropriate experience in concession-based projects and hold appropriate positions as decision-makers so as to give credence to collected data. The highest significant factors were identified through the relative significance index (RSI). By exploring factor analysis, the factors were condensed for discussion under appropriate component headings. The value of Kaiser–Meyer–Olkin (KMO, 0.755) measure of sampling adequacy tests carried out showed that the data collected were adequate for the factor analysis, and the Bartlett’s test of sphericity (χ2 = 1,799.339; df = 630; p < 0.001) was highly significant.

Findings

Factors influencing private party performance clustered under eight components, namely, technical, market maturity, political, legal, finance, procurement, incentive and regulation. However, component items including level of understanding of public–private alliance transactions, stability of exchange rate and provisions for reversion of policies were found to be highly significant. On the other hand, status of domestication and implementation of international laws/codes, predictability in legal regime and enforcement and extent of jurisdictional definition of land usage were least significant.

Originality/value

Findings would guide private investors in the preparation of robust investment packages that reduce risks and seemingly unavoidable opportunistic tendencies associated with public–private partnership projects in developing economies.
Air pollution alters Staphylococcus aureus and Streptococcus pneumoniae biofilms, antibiotic tolerance and colonisation
Authors: Hussey Shane. J. K. , Purves Joanne , Allcock Natalie , Fernandes Vitor E. , Monks Paul S. , Ketley Julian M. , Andrew Peter W. , Morrissey Julie A.
Published: February 2017

Air pollution is the world's largest single environmental health risk (WHO). Particulate matter such as black carbon is one of the main components of air pollution. The effects of particulate matter on human health are well established however the effects on bacteria, organisms central to ecosystems in humans and in the natural environment, are poorly understood. We report here for the first time that black carbon drastically changes the development of bacterial biofilms, key aspects of bacterial colonisation and survival. Our data show that exposure to black carbon induces structural, compositional and functional changes in the biofilms of both S. pneumoniae and S. aureus. Importantly, the tolerance of the biofilms to multiple antibiotics and proteolytic degradation is significantly affected. Additionally, our results show that black carbon impacts bacterial colonisation in vivo. In a mouse nasopharyngeal colonisation model, black carbon caused S. pneumoniae to spread from the nasopharynx to the lungs, which is essential for subsequent infection. Therefore our study highlights that air pollution has a significant effect on bacteria that has been largely overlooked. Consequently these findings have important implications concerning the impact of air pollution on human health and bacterial ecosystems worldwide.
Ethanol production by the hyperthermophilic archaeon Pyrococcus furiosus by expression of bacterial bifunctional alcohol dehydrogenases
Authors: Keller Matthew W. , Lipscomb Gina L. , Nguyen Diep M. , Crowley Alexander T. , Schut Gerrit J. , Scott Israel , Kelly Robert M. , Adams Michael W. W.
Published: February 2017

Ethanol is an important target for the renewable production of liquid transportation fuels. It can be produced biologically from pyruvate, via pyruvate decarboxylase, or from acetyl‐CoA, by alcohol dehydrogenase E (AdhE). Thermophilic bacteria utilize AdhE, which is a bifunctional enzyme that contains both acetaldehyde dehydrogenase and alcohol dehydrogenase activities. Many of these organisms also contain a separate alcohol dehydrogenase (AdhA) that generates ethanol from acetaldehyde, although the role of AdhA in ethanol production is typically not clear. As acetyl‐CoA is a key central metabolite that can be generated from a wide range of substrates, AdhE can serve as a single gene fuel module to produce ethanol through primary metabolic pathways. The focus here is on the hyperthermophilic archaeon Pyrococcus furiosus, which grows by fermenting sugar to acetate, CO2 and H2. Previously, by the heterologous expression of adhA from a thermophilic bacterium, P. furiosus was shown to produce ethanol by a novel mechanism from acetate, mediated by AdhA and the native enzyme aldehyde oxidoreductase (AOR). In this study, the AOR gene was deleted from P. furiosus to evaluate ethanol production directly from acetyl‐CoA by heterologous expression of the adhE gene from eight thermophilic bacteria. Only AdhEs from two Thermoanaerobacter strains showed significant activity in cell‐free extracts of recombinant P. furiosus and supported ethanol production in vivo. In the AOR deletion background, the highest amount of ethanol (estimated 61% theoretical yield) was produced when adhE and adhA from Thermoanaerobacter were co‐expressed.
Sex and Adolescent Ethanol Exposure Influence Pavlovian Conditioned Approach
Authors: Madayag Aric C. , Stringfield Sierra J. , Reissner Kathryn J. , Boettiger Charlotte A. , Robinson Donita L.
Published: February 2017

Background

Alcohol use among adolescents is widespread and a growing concern due to long‐term behavioral deficits, including altered Pavlovian behavior, that potentially contribute to addiction vulnerability. We tested the hypothesis that adolescent intermittent ethanol (AIE) exposure alters Pavlovian behavior in males and females as measured by a shift from goal‐tracking to sign‐tracking. Additionally, we investigated GLT‐1, an astrocytic glutamate transporter, as a potential contributor to a sign‐tracking phenotype.

Methods

Male and female Sprague‐Dawley rats were exposed to AIE (5 g/kg, intragastric) or water intermittently 2 days on and 2 days off from postnatal day (P) 25 to 54. Around P70, animals began 20 daily sessions of Pavlovian conditioned approach (PCA), where they learned that a cue predicted noncontingent reward delivery. Lever pressing indicated interaction with the cue, or sign‐tracking, and receptacle entries indicated approach to the reward delivery location, or goal‐tracking. To test for effects of AIE on nucleus accumbens (NAcc) excitatory signaling, we isolated membrane subfractions and measured protein levels of the glutamate transporter GLT‐1 after animals completed behavior as a measure of glutamate homeostasis.

Results

Females exhibited elevated sign‐tracking compared to males with significantly more lever presses, faster latency to first lever press, and greater probability to lever press in a trial. AIE significantly increased lever pressing while blunting goal‐tracking, as indicated by fewer cue‐evoked receptacle entries, slower latency to receptacle entry, and lower probability to enter the receptacle in a trial. No significant sex‐by‐exposure interactions were observed in sign‐ or goal‐tracking metrics. Moreover, we found no significant effects of sex or exposure on membrane GLT‐1 expression in the NAcc.

Conclusions

Females exhibited enhanced sign‐tracking compared to males, while AIE decreased goal‐tracking compared to control exposure. Our findings support the hypothesis that adolescent binge ethanol can shift conditioned behavior from goal‐ to cue‐directed in PCA, especially in females.
Concomitant Glucocorticoid Treatment Prevents the Development of β‐Adrenoceptor Desensitization in the Guinea Pig Lung
Authors: Salonen Raimo O.
Published: February 2017

The aim of the present study was to investigate, whether concomitant administration of the synthetic glucocorticoid betamethasone (BM), theophylline (THEO), or the muscarinic antagonist ipratropium bromide (IPRA) could influence the desensitization‐associated decrease of β‐adrenoceptors in the guinea pig lung during prolonged in vivo treatment with the β2‐agonist terbutaline (TER). The animals were sacrificed 20 hrs after the last drug dosage and the lung membrane homogenates were prepared for 3H‐dihydroalprenolol (3H‐DHA) binding in vitro. Treatment with TER 200 µg/kg subcutaneously twice a day for five days decreased by 22% the maximum number of binding sites (Bmax) at saturation in comparison with the saline‐treated controls. Concomitant administration of BM 2 mg/kg intraperitoneally abolished this effect of TER, whereas THEO 20 mg/kg or IPRA 5 µg/kg failed to modify it. None of the in vivo treatments affected the binding affinity of 3H‐DHA. In vitro, TER inhibited in a concentration‐dependent manner 3H‐DHA binding to the lung membranes of untreated guinea pigs. At high concentrations IPRA, but not THEO or BM, showed some binding to the β‐receptors as well. Thus, it is concluded that glucocorticoids may prevent β‐adrenoceptor desensitization in the lungs via an indirect mechanism, e.g. inhibition of phospholipase A2 enzyme.
Diurnal Variations in Serum Lithium and Renal Lithium Clearance in Rats given Lithium as a Single Small Dose or as Multiple High Doses
Authors: Olesen O. Vendelin , Thomsen Klaus
Published: February 2017

Clearance determinations were carried out in three groups of rats: (1) A high lithium group given food to which 70 mmol/kg of lithium were added for 4–6 weeks leading to a mean serum lithium concentration of 0.85 mmol/l, (2) a low lithium group given food to which 15 mmol/kg of lithium were added for two days before the clearance period leading to a mean serum lithium concentration of 0.22 mmol/l, and (3) a group given the same food without lithium. The sodium and potassium contents of the food were kept high in order to avoid lithium‐induced development of negative sodium balance and excessive polyuria. The rats were housed in four rooms with 6‐hour displaced 24‐hour light‐dark cycles. The results showed that high doses of lithium led to a significant increase of the lithium clearance and the urine flow. Small amounts of lithium influenced neither the clearance values nor the urine flow. All renal variables were increased by about 50–100% during the dark period. The serum lithium concentration was least influenced by the diurnal rhythm. It is concluded that serum lithium concentrations measured at any time of the day are fairly representative of the 24 hours. A lithium clearance measured during daytime is valid for this period only. Long‐term lithium treatment leads to an increase of the renal lithium clearance but does not diminish the normal diurnal rhythm of the kidney function.
5‐HT‐Uptake Inhibition Potentiates Antinociception Induced by Morphine, Pethidine, Methadone and Ketobemidone in Rats
Authors: Larsen Jens-Jørgen , Hyttel John
Published: February 2017

The effect of the specific 5‐HT‐uptake inhibitor citalopram on the antinociception induced by morphine, pethidine, methadone and ketobemidone was examined in rats by means of the hot plate test. Further the 5‐HT‐uptake‐inhibiting potency of these opioid‐receptor stimulants was examined in vitro in rat brain synaptosomes. In doses devoid of antinociceptive activity, citalopram in a dose‐dependent manner potentiated the antinociception induced by the four opioid analgesics. The potentiation of the ketobemidone‐induced antinociception was not influenced by the spasmolytic agent A 29 (N,N‐dimethyl‐3,3‐diphenyl‐l‐methylallylamine) which together with ketobemidone constitutes the active substances in Ketogan®. The 5‐HT‐uptake‐inhibiting potencies of the opioid receptor stimulants were from 21 to more than 56000 times lower than that of citalopram, the order of potency being methadone> pethidine> ketobemidone > morphine. The results support the suggested role of 5‐HT in morphine‐induced antinociception and indicate a similar role in the antinociceptive effect induced by other opioid‐receptor stimulants.
Calcium Dependence of Contractile Activation of Isolated Sheep Urethra I: Responses to Electrical Stimulation
Authors: Garcia-Pascual Angeles , Costa Gonzalo , Garcia-Sacristan Albino , Andersson Karl-Erik
Published: February 2017

In isolated sheep urethral smooth muscle at resting tension, responses elicited by electrical stimulation of nerves were either contraction (40%), or contraction preceded by relaxation (60%). All responses were suppressed by tetrodotoxin (TTX), but at stimulation frequencies exceeding 16 Hz, there was a small TTX resistant contraction, which at the highest frequency used (50 Hz) amounted to about 15% of the total response. α‐Adrenoceptor blockade suppressed the contractions, as did chemical sympathectomy with 6‐hydroxydopamine. In calcium‐free medium all electrically induced contractions were abolished. Nifedipine, verapamil, and lanthanum had concentration‐dependent depressant actions, whereas Bay K 8644 (10−6 M) significantly increased the responses. In preparations prelabelled with3H‐noradrenaline, electrical stimulation caused a release of 3H that could be blocked by TTX, and effectively reduced by calcium‐free medium and lanthanum. However, the release was unaffected by nifedipine, and moderately reduced by high concentrations of verapamil (10−5 M). It is suggested that contractile responses to electrical stimulation in isolated sheep urethral smooth muscle are mediated by the sympathetic nervous system, mainly through release of noradrenaline stimulating postjunctional α1‐adrenoceptors. The release of noradrenaline, as well as the action of released noradrenaline on postjunctional membranes are calcium‐dependent. However, the calcium entry pathways used are partly different from those inhibited by organic calcium antagonists.
Calcium Dependence of Contractile Activation of Isolated Sheep Urethra II: Responses to Exogenous Noradrenaline
Authors: Garcia-Pascuar Angeles , Costa Gonzalo , Garcia-Sacristan Albino , Andersson Karl-Erik
Published: February 2017

Isolated smooth muscle of sheep urethra responded to exogenous noradrenaline (NA) with a concentrationdependent contraction. After exposing the preparations for 30 min. to calcium‐free medium, NA in a submaximal concentration was still able to produce a contractile response amounting to 36% of control value in calcium‐containing solution. Readmission of calcium (administered cumulatively) restored the response in a concentration‐related fashion to 85% (at 5 mM calcium) of control level. Nifedipine and verapamil failed to inhibit these graded calcium contractions in the presence of NA. Verapamil and diltiazem also failed to significantly prevent contraction induced by NA in a submaximum concentration, but nifedipine showed a concentration‐dependent inhibitory effect, with a potency 1000 times lower than that observed on K+ (124 mM) induced contractions. In calcium‐free medium, repeated applications of NA at 30 min. intervals, induced a progressive reduction in contractile amplitude. Nifedipine or verapamil did not affect the time course for recovery of NA‐induced contraction when the preparations were returned to calcium containing medium, but the recovery was blocked almost completely by lanthanum. Furthermore, lanthanum abolished the remaining NA contraction in calcium‐free medium. The results suggest that NA‐induced contraction in isolated sheep urethra is dependent on both influx of extracellular calcium and on release of intracellular calcium. Calcium influx for contractile activation and refilling of intracellular stores seem to occur through membrane channels that can only partly be blocked with calcium antagonists.
Interaction of Doxapram and Pentobarbital in Mice
Authors: Ishikawa Masaaki , Suzuki Ichiko , Ozaki Masayasu , Takayanagi Yoshio , Sasaki Ken-ichi
Published: February 2017

We found a statistically significant increase in duration of pentobarbital‐induced narcosis in doxapram‐treated mice. The influence of doxapram (a respiratory stimulant) pretreatment on pentobarbital metabolism in mice was assessed by measurements of sleeping times, hypothermia, LD50 values, hepatic microsomal metabolism and relative plasma and brain levels of pentobarbital. When doxapram was given intraperitoneally 60 min. prior to administration of pentobarbital, doxapram potentiated pentobarbital‐induced narcosis in a dose‐ and time‐dependent manner, but had no effect on onset time. Doxapram potentiated hypothermia, increased acute toxicity, and prolonged the pentobarbital half‐life in brain and plasma, but measurement of the concentration of pentobarbital in the brain and plasma immediately upon recovery from narcosis showed that there were no differences in any of the groups examined. Also, brain‐to‐plasma ratios of pentobarbital did not differ between the control and doxapram‐treated groups. Doxapram competitively inhibited the hepatic metabolism of pentobarbital in 9000 × g supernatant incubation mixtures. The results obtained from these experiments indicate that inhibition of drug‐metabolizing enzymes by doxapram may account for its enhancement of the duration of pentobarbitalinduced narcosis.
SketchSoup: Exploratory Ideation Using Design Sketches
Authors: Arora R. , Darolia I. , Namboodiri V. P. , Singh K. , Bousseau A.
Published: February 2017

A hallmark of early stage design is a number of quick‐and‐dirty sketches capturing design inspirations, model variations and alternate viewpoints of a visual concept. We present SketchSoup, a workflow that allows designers to explore the design space induced by such sketches. We take an unstructured collection of drawings as input, along with a small number of user‐provided correspondences as input. We register them using a multi‐image matching algorithm, and present them as a 2D interpolation space. By morphing sketches in this space, our approach produces plausible visualizations of shape and viewpoint variations despite the presence of sketch distortions that would prevent standard camera calibration and 3D reconstruction. In addition, our interpolated sketches can serve as inspiration for further drawings, which feed back into the design space as additional image inputs. SketchSoup thus fills a significant gap in the early ideation stage of conceptual design by allowing designers to make better informed choices before proceeding to more expensive 3D modelling and prototyping. From a technical standpoint, we describe an end‐to‐end system that judiciously combines and adapts various image processing techniques to the drawing domain—where the images are dominated not by colour, shading and texture, but by sketchy stroke contours.
NeuroLens: Data‐Driven Camera Lens Simulation Using Neural Networks
Authors: Zheng Quan , Zheng Changwen
Published: February 2017

Rendering with full lens model can offer images with photorealistic lens effects, but it leads to high computational costs. This paper proposes a novel camera lens model, NeuroLens, to emulate the imaging of real camera lenses through a data‐driven approach. The mapping of image formation in a camera lens is formulated as imaging regression functions (IRFs), which map input rays to output rays. IRFs are approximated with neural networks, which compactly represent the imaging properties and support parallel evaluation on a graphics processing unit (GPU). To effectively represent spatially varying imaging properties of a camera lens, the input space spanned by incident rays is subdivided into multiple subspaces and each subspace is fitted with a separate IRF. To further raise the evaluation accuracy, a set of neural networks is trained for each IRF and the output is calculated as the average output of the set. The effectiveness of the NeuroLens is demonstrated by fitting a wide range of real camera lenses. Experimental results show that it provides higher imaging accuracy in comparison to state‐of‐the‐art camera lens models, while maintaining the high efficiency for processing camera rays.
Need for adaptation: transformation of temporary houses
Authors: Wagemann Elizabeth
Published: February 2017

Building permanent accommodation after a disaster takes time for reasons including the removal of debris, the lack of available land, and the procurement of resources. In the period in‐between, affected communities find shelter in different ways. Temporary houses or transitional shelters are used when families cannot return to their pre‐disaster homes and no other alternative can be provided. In practice, families stay in a standard interim solution for months or even years while trying to return to their routines. Consequently, they adapt their houses to meet their midterm needs. This study analysed temporary houses in Chile and Peru to illustrate how families modify them with or without external support. The paper underlines that guidance must be given on how to alter them safely and on how to incorporate the temporary solution into the permanent structure, because families adapt their houses whether or not they are so designed.
Factors influencing attendance at structured education for Type 1 diabetes in south London
Authors: Harris S. M. , Shah P. , Mulnier H. , Healey A. , Thomas S. M. , Amiel S. A. , Hopkins D.
Published: February 2017

Aim

To investigate the factors influencing uptake of structured education for people with Type 1 diabetes in our local population in order to understand why such uptake is low.

Methods

We conducted a cross‐sectional database study of adults with Type 1 diabetes in two south London boroughs, analysed according to Dose Adjustment For Normal Eating (DAFNE) attendance or non‐attendance. Demographics, glycaemic control and service use, with subset analysis by ethnicity, were compared using univariate analysis. An exploratory regression model was used to identify influencing factors.

Results

The analysis showed that 73% of adults had not attended the DAFNE programme. For non‐attenders vs attenders, male gender (59 vs 48%; P = 0.002), older age (39 vs 35 years; P < 0.001), non‐white ethnicity (30 vs 20%; P = 0.001) and coming from an area of social deprivation (index of multiple deprivation score 31 vs 28; P < 0.001) were associated with non‐attendance. The difference in gender (88% men vs 70% women; P < 0.001) and age (43 vs 34 years) persisted in the non‐white group. Regression analysis showed that higher baseline HbA1c level (odds ratio 1.96; P = 0.004), younger age (odds ratio 0.98; P = 0.001) and lower social deprivation (odds ratio 0.52; P = 0.001) was associated with attendance.

Conclusion

Socio‐economic status and factors perceived as indicating greater severity of disease (HbA1c) influence attendance at DAFNE. More work is necessary to understand the demography of non‐attenders to aid future service design and alternative engagement strategies for these groups.
Glycated haemoglobin (HbA1c) and fasting plasma glucose relationships in sea‐level and high‐altitude settings
Authors: Bazo‐Alvarez J. C. , Quispe R. , Pillay T. D. , Bernabé‐Ortiz A. , Smeeth L. , Checkley W. , Gilman R. H. , Málaga G. , Miranda J. J.
Published: February 2017

Aim

Higher haemoglobin levels and differences in glucose metabolism have been reported among high‐altitude residents, which may influence the diagnostic performance of HbA1c. This study explores the relationship between HbA1c and fasting plasma glucose (FPG) in populations living at sea level and at an altitude of > 3000 m.

Methods

Data from 3613 Peruvian adults without a known diagnosis of diabetes from sea‐level and high‐altitude settings were evaluated. Linear, quadratic and cubic regression models were performed adjusting for potential confounders. Receiver operating characteristic (ROC) curves were constructed and concordance between HbA1c and FPG was assessed using a Kappa index.

Results

At sea level and high altitude, means were 13.5 and 16.7 g/dl (P > 0.05) for haemoglobin level; 41 and 40 mmol/mol (5.9% and 5.8%; P < 0.01) for HbA1c; and 5.8 and 5.1 mmol/l (105 and 91.3 mg/dl; P < 0.001) for FPG, respectively. The adjusted relationship between HbA1c and FPG was quadratic at sea level and linear at high altitude. Adjusted models showed that, to predict an HbA1c value of 48 mmol/mol (6.5%), the corresponding mean FPG values at sea level and high altitude were 6.6 and 14.8 mmol/l (120 and 266 mg/dl), respectively. An HbA1c cut‐off of 48 mmol/mol (6.5%) had a sensitivity for high FPG of 87.3% (95% confidence interval (95% CI) 76.5 to 94.4) at sea level and 40.9% (95% CI 20.7 to 63.6) at high altitude.

Conclusion

The relationship between HbA1c and FPG is less clear at high altitude than at sea level. Caution is warranted when using HbA1c to diagnose diabetes mellitus in this setting.
The Economics of Property Rights in Early and Medieval Christianity
Authors: Koehler Benedikt
Published: February 2017

Early and medieval Christianity pioneered an economics of property rights that had no precedent in antiquity. The early Church Fathers Tertullian, Ambrose, and John Chrysostomos successively evolved conceptions of the right to own property as a prerequisite for poor relief, and the basis of the right to own property was later formulated by Pope John XXII to settle a dispute on this issue instigated by Francis of Assisi. This article challenges assessments advanced by Joseph Schumpeter, Jacob Viner, and Frank Knight, who argued that the doctrines of Christianity were devoid of economics, and draws attention to the work of Georg Ratzinger (1844–1899), who first expounded how in early Christianity property rights and poor relief were linked.
Monetary Ratios in a Modern Regime: Why the Monetary Base still Matters
Authors: Evans Anthony J.
Published: February 2017

A recent paper Bank of England paper cast doubt on the ‘textbook’ model of the money multiplier. However, this criticism is inconsistent and misleading. It understates the importance of the central bank's control over the monetary base, and how this influences the money supply. The confusion suggests that it would be more fruitful to conduct analysis using the currency‐deposit ratio and reserve‐deposit ratio rather than the money multiplier, and evidence from 1998–2013 is provided. This article explains how these ratios depend on the monetary regime, and the distinction between inside and outside money. Although a modern regime alters the way that money creation occurs, the monetary base still matters.
A Perfect Impasse? Cuba's Move Towards the Market and the United States' Move Towards Cuba
Authors: Wilkinson Stephen
Published: February 2017

This article first analyses the internal economic trajectory of the Cuban economic reforms and evaluates their effectiveness in delivering the extensive and intensive development needed to correct Cuba's structural and economic imbalances. It concludes that without the lifting of the US economic sanctions success will at best be only partial, with serious implications for long‐term stability. The article then evaluates the reasons for the US economic sanctions against Cuba and argues that while the embargo policy might have failed to topple the Cuban communist regime, it has served other, largely unacknowledged, purposes that are important in explaining why the policy has persisted. The article concludes by suggesting that the US is not likely to jettison the sanctions regime while Cuba's single‐party, state‐led economic system remains. At the same time, Cuba is not likely to jettison its single‐party system while the sanctions remain.
REFORM SUPPORT IN TIMES OF CRISIS: THE ROLE OF FAMILY TIES
Authors: Brumm Elias , Brumm Johannes
Published: February 2017

We argue that an important determinant of voters' support for economic reform is the strength of family ties. While the “crisis hypothesis” predicts that crises facilitate reform, we show in a political economy model that this relation can break down, and even reverse, when agents take into account the effect of reform on their family members. Applied to southern European countries with strong family ties, the model rationalizes why the extremely high (youth) unemployment following the Great Recession has not led to more substantial labor market reforms. In such countries austerity might block rather than foster additional structural reforms. (JEL D64, D72, J48)