Bats perceptually weight prey cues across sensory systems when hunting in noise.

Anthropogenic noise can interfere with environmental information processing and thereby reduce survival and reproduction. Receivers of signals and cues in particular depend on perceptual strategies to adjust to noisy conditions. We found that predators that hunt using prey sounds can reduce the negative impact of noise by making use of prey cues conveyed through additional sensory systems. In the presence of masking noise, but not in its absence, frog-eating bats preferred and were faster in attacking a robotic frog emitting multiple sensory cues. The behavioral changes induced by masking noise were accompanied by an increase in active localization through echolocation. Our findings help to reveal how animals can adapt to anthropogenic noise and have implications for the role of sensory ecology in driving species interactions.

Multimodal cues improve prey localization under complex environmental conditions.

Predators often eavesdrop on sexual displays of their prey. These displays can provide multimodal cues that aid predators, but the benefits in attending to them should depend on the environmental sensory conditions under which they forage. We assessed whether bats hunting for frogs use multimodal cues to locate their prey and whether their use varies with ambient conditions. We used a robotic set-up mimicking the sexual display of a male túngara frog (Physalaemus pustulosus) to test prey assessment by fringe-lipped bats (Trachops cirrhosus). These predatory bats primarily use sound of the frog's call to find their prey, but the bats also use echolocation cues returning from the frog's dynamically moving vocal sac. In the first experiment, we show that multimodal cues affect attack behaviour: bats made narrower flank attack angles on multimodal trials compared with unimodal trials during which they could only rely on the sound of the frog. In the second experiment, we explored the bat's use of prey cues in an acoustically more complex environment. Túngara frogs often form mixed-species choruses with other frogs, including the hourglass frog (Dendropsophus ebraccatus). Using a multi-speaker set-up, we tested bat approaches and attacks on the robofrog under three different levels of acoustic complexity: no calling D. ebraccatus males, two calling D. ebraccatus males and five D. ebraccatus males. We found that bats are more directional in their approach to the robofrog when more D. ebraccatus males were calling. Thus, bats seemed to benefit more from multimodal cues when confronted with increased levels of acoustic complexity in their foraging environments. Our data have important consequences for our understanding of the evolution of multimodal sexual displays as they reveal how environmental conditions can alter the natural selection pressures acting on them.

The greenhouse emissions footprint of free-range eggs.

Eggs are an increasingly significant source of protein for human consumption, and the global poultry industry is the single fastest-growing livestock sector. In the context of international concern for food security and feeding an increasingly affluent human population, the contribution to global greenhouse-gas (GHG) emissions from animal protein production is of critical interest. We calculated the GHG emissions footprint for the fastest-growing sector of the UK egg market: free-range production in small commercial units on mixed farms. Emissions are calculated to current Intergovernmental Panel on Climate Change and UK standards (PAS2050): including direct, indirect, and embodied emissions from cradle to farm gate compatible with a full product life-cycle assessment. We present a methodology for the allocation of emissions between ruminant and poultry enterprises on mixed farms. Greenhouse gas emissions averaged a global warming potential of 2.2 kg of CO2e/dozen eggs, or 1.6 kg of CO2equivalent (e)/kg (assuming average egg weight of 60 g). One kilogram of protein from free-range eggs produces 0.2 kg of CO2e, lower than the emissions from white or red meat (based on both kg of meat and kg of protein). Of these emissions, 63% represent embodied carbon in poultry feed. A detailed GHG emissions footprint represents a baseline for comparison with other egg production systems and sources of protein for human consumption. Eggs represent a relatively low-carbon supply of animal protein, but their production is heavily dependent on cereals and soy, with associated high emissions from industrial nitrogen production, land-use change, and transport. Alternative sources of digestible protein for poultry diets are available, may be produced from waste processing, and would be an effective tool for reducing the industry's GHG emissions and dependence on imported raw materials.

Risky ripples allow bats and frogs to eavesdrop on a multisensory sexual display.

Animal displays are often perceived by intended and unintended receivers in more than one sensory system. In addition, cues that are an incidental consequence of signal production can also be perceived by different receivers, even when the receivers use different sensory systems to perceive them. Here we show that the vocal responses of male túngara frogs (Physalaemus pustulosus) increase twofold when call-induced water ripples are added to the acoustic component of a rival's call. Hunting bats (Trachops cirrhosus) can echolocate this signal by-product and prefer to attack model frogs when ripples are added to the acoustic component of the call. This study illustrates how the perception of a signal by-product by intended and unintended receivers through different sensory systems generates both costs and benefits for the signaler.

A capabilities approach to population health and public policy-making.

BACKGROUND: The objective of this study is to outline a capabilities approach to the social determinants of population health and to compare its explanatory power and implications for public policy-making with psychosocial approaches. METHODS: A model linking the structures of economic and social relations to health outcomes is developed and logistic methods used to confirm its base validity for a representative sample of 16,488 citizens in 19 developed democracies drawn from the World Values Surveys of 1990 and 2005. Self-reported health is the dependent variable. Age, gender, education, employment status, self-mastery, income, autonomy at work, ties to family and friends, subjective social status, associational memberships and sense of national belonging are considered. RESULTS: At baseline, risk ratios reflecting movement from the 25th to 75th percentile in the distribution of the variable indicate that increases in income reduce the likelihood of poor health (0.78; 0.73-0.82) as does higher autonomy at work (0.90; 0.85-0.94) but so does access to social resources reflected in ties to family and friends (0.89; 0.86-0.92), associational memberships (0.93; 0.89-0.98), subjective social status (0.77; 0.54-0.90) while the absence of feelings of national belonging increases the likelihood of poor health (1.14; 1.06-1.23). CONCLUSION: The results suggest that population health is dependent on the distribution of social as well as economic resources along the dimensions predicted by a capabilities model. Governments should be attentive to the impact of policy on the distribution of social, as well as economic, resources.

Interactions of multisensory components perceptually rescue túngara frog mating signals.

Sexual signals are often complex and perceived by multiple senses. How animals integrate signal components across sensory modalities can influence signal evolution. Here we show that two relatively unattractive signals that are perceived acoustically and visually can be combined in a pattern to form a signal that is attractive to female túngara frogs. Such unanticipated perceptual effects suggest that the evolution of complex signals can occur by alteration of the relationships among already-existing traits.

Prevalence of thyroid antibodies in Nigerian patients.

BACKGROUND: Thyroid antibody testing is not routinely available in developing countries, and few studies have measured thyroid antibodies in Africans. The significance of thyroid autoimmunity in an African setting is thus unclear. AIM: To determine the prevalence of thyroid antibodies in patients attending a Nigerian teaching hospital. DESIGN: Prospective survey. METHODS: We measured antibodies to thyroglobulin (TgAb) and thyroid peroxidase (TPOAb) using an ELISA technique in 104 patients with various thyroid pathologies attending an endocrine referral centre in Lagos, Nigeria. Patients were clinically grouped into Graves' disease (GD) (n = 69), simple non-toxic goitre (SNTG) (n = 21), toxic nodular goitre (TNG) (n = 8) and suspected Hashimoto's thyroiditis (HT) (n = 6). Blood donors without thyroid disease (n = 100) acted as controls. RESULTS: TgAb and TPOAb were found in 4% and 7%, respectively, of healthy adult controls, 11.6 and 76.8% of patients with GD, 25% and 12.5% of patients with TNG and 9.52% and 14.29% of patients with SNTG. TPOAb testing confirmed HT in six patients, and identified two further cases that would have been misdiagnosed without antibody testing. DISCUSSION: Thyroid autoimmunity appears more common in these Nigerian patients than in previous reports from Africa, and TPOAb was significantly associated with auto-immune thyroid disease. The clinical utility of these antibody measurements requires further evaluation in a wider African population.

GEST: a gene expression search tool based on a novel Bayesian similarity metric.

Gene expression array technology has made possible the assay of expression levels of tens of thousands of genes at a time; large databases of such measurements are currently under construction. One important use of such databases is the ability to search for experiments that have similar gene expression levels as a query, potentially identifying previously unsuspected relationships among cellular states. Such searches depend crucially on the metric used to assess the similarity between pairs of experiments. The complex joint distribution of gene expression levels, particularly their correlational structure and non-normality, make simple similarity metrics such as Euclidean distance or correlational similarity scores suboptimal for use in this application. We present a similarity metric for gene expression array experiments that takes into account the complex joint distribution of expression values. We provide a computationally tractable approximation to this measure, and have implemented a database search tool based on it. We discuss implementation issues and efficiency, and we compare our new metric to other standard metrics.

Efficacy of granular deltamethrin against Ixodes scapularis and Amblyomma americanum (Acari: Ixodidade) nymphs.

A single barrier application of granular deltamethrin to the woodland edges of a forested residential community in late spring significantly reduced the abundance of Ixodes scapularis Say nymphs. The application also suppressed the population of Amblyomma americanum (L.) nymphs, which recently became established in the study area. The efficacy of deltamethrin is compared with other commonly used acaricides.

Role of laparoscopic salpingostomy in the treatment of hydrosalpinx.

OBJECTIVE: To determine pregnancy rates after laparoscopic salpingostomy in occlusive distal tubal disease. To evaluate the relative impact of various historical, physical, and operative factors on pregnancy outcome using a multivariate statistical analysis. DESIGN: Prospective cohort. SETTING: University-affiliated tertiary care infertility clinic. PATIENT(S): One hundred thirty-nine infertile women with occlusive distal tube disease. INTERVENTION(S): Laparoscopic salpingostomy. MAIN OUTCOME MEASURE(S): The occurrence of intrauterine (IUP) and ectopic pregnancy (EP). RESULT(S): The overall IUP and EP rates were 24.5% and 16.5%, respectively. Analysis of historical variables, assessed independently, demonstrated a significantly higher IUP rate with a positive history of gonorrhea and a significantly higher EP rate with a positive history of pelvic inflammatory disease, lack of history of intrauterine device (IUD) usage, or the performance of a bilateral procedure. The logistic regression model to predict intrauterine pregnancy had an overall predictive value of 77.5% and included the following significant variables: secondary infertility, positive history of gonorrhea, and the operative finding of moderate periadnexal adhesions. The logistic regression model to predict ectopic pregnancy had an overall predictive value of 89.0% and included the following significant variables: previous ectopic pregnancy, negative history of IUD use, positive history of PID, a bilateral procedure, and perihepatic adhesions. CONCLUSION(S): Operative laparoscopy may be effective for the correction of hydrosalpinges in selected patients. The probability of achieving an intrauterine or an ectopic pregnancy can be predicted based on combinations of significant variables.

High-resolution solid state 13C nuclear magnetic resonance spectra of 3,4-methylenedioxyamphetamine hydrochloride and related compounds and their mixtures with lactose.

Differences between solution and solid state 13C nuclear magnetic resonance spectra of some amphetamines namely, 3,4-methylenedioxyamphetamine HCI, (R.S)-MDA HCI, the methyl derivative 3,4-methylenedioxy-N-methylamphetamine x HCI, (R,S)-MDMA x HCI, the ethyl derivative, (R,S)-MDEA x HCI, and the analogues (R,S)-methamphetamine HCI, (-)-ephedrine x HCI (the 3R,2S enantiomer as numbered here), and (+)-pseudo-ephedrine x HCI (the 3S,2S enantiomer as numbered here) have been studied and related to their crystal structure. For (R,S)-MDMA x HCI, an interesting new finding is that the observed solid state chemical shifts changed when lactose monohydrate was added as a dry powder and thoroughly mixed at room temperature. This experiment mimicked the illicit production of "Ecstasy" tablets. The mixing phenomena with lactose observed for (R.S)-MDMA x HCI was not seen for the other compounds studied. The results are discussed in terms of hydrogen bonding and possible polymorphs. It appears that lactose affects crystal packing by reducing conformational rigidity so that the molecule more closely resembles that in solution.

Tobacco craving: intensity-related effects of imagery scripts in drug abusers.

Two experiments were conducted to determine whether active imagery would elicit tobacco craving in smokers with histories of drug abuse who were not interested in quitting smoking. In Experiment 1, the authors used scripts that contained positive, negative, or neutral affective content with and without descriptions of smoking urge. Scripts with urge content and negative affect scripts increased subjective reports of tobacco craving. An interaction between affective manipulation and urge content was observed on self-reported mood. In Experiment 2, positive affect scripts that varied in amount of urge content produced an orderly increase in tobacco craving as a function of urge intensity, suggesting that changes were specific to the imagery manipulation. In both experiments, increases in tobacco craving were positively correlated with craving for drug of choice, suggesting that stimuli that engender smoking urges may occasion craving for other drugs of abuse.

Identification of putative programmed -1 ribosomal frameshift signals in large DNA databases.

The cis-acting elements that promote efficient ribosomal frameshifting in the -1 (5') direction have been well characterized in several viral systems. Results from many studies have convincingly demonstrated that the basic molecular mechanisms governing programmed -1 ribosomal frameshifting are almost identical from yeast to humans. We are interested in testing the hypothesis that programmed -1 ribosomal frameshifting can be used to control cellular gene expression. Toward this end, a computer program was designed to search large DNA databases for consensus -1 ribosomal frameshift signals. The results demonstrated that consensus programmed -1 ribosomal frameshift signals can be identified in a substantial number of chromosomally encoded mRNAs and that they occur with frequencies from two- to sixfold greater than random in all of the databases searched. A preliminary survey of the databases resulting from the computer searches found that consensus frameshift signals are present in at least 21 homologous genes from different species, 2 of which are nearly identical, suggesting evolutionary conservation of function. We show that four previously described missense alleles of genes that are linked to human diseases would disrupt putative programmed -1 ribosomal frameshift signals, suggesting that the frameshift signal may be involved in the normal expression of these genes. We also demonstrate that signals found in the yeast RAS1 and the human CCR5 genes were able to promote significant levels of programmed -1 ribosomal frameshifting. The significance of these frameshifting signals in controlling gene expression is not known, however.

Smoking after nicotine deprivation enhances cognitive performance and decreases tobacco craving in drug abusers.

This study investigated the effects of nicotine deprivation and smoking on cognitive abilities and tobacco craving. Twenty smokers with histories of drug abuse completed the Questionnaire on Smoking Urges (QSU) and two cognitive tests before and after smoking two cigarettes during two 90-min sessions. After two cigarettes were smoked at Session 1, subjects were tobacco abstinent for 18 h until Session 2 the next morning. Response time on a logical reasoning test was unchanged by tobacco deprivation and was faster after smoking on Session 2. Deprivation slowed responding on a letter search test, which was reversed by smoking to pre-deprivation baseline. Tobacco deprivation increased scores on the QSU; smoking after deprivation reduced craving scores to smoking baseline levels. These results confirmed the utility of the QSU to measure changes in craving induced by tobacco deprivation and smoking. Further, the data suggest that deprivation-induced deficits and smoking-induced enhancements in performance may be specific to certain cognitive domains.

Nucleic acid sequences coding for internal antisense peptides: are there implications for protein folding and evolution?

We have asked whether coding segments of nucleic acids generate amino acid sequences which have an antisense relationship to other amino acid sequences in the same chain (i.e. 'Internal Antisense'), and if so, could the internal antisense content be related to the structure of the encoded protein? Computer searches were conducted with the coding sequences for 132 proteins. The result for each search of a specific sequence was compared to the mean result obtained from 1000 randomly assembled nucleic acid chains whose length and base composition were identical to that of the native sequences. The study was conducted in all three reading frames. The normal reading frame (frame one) was found to be contain lower amounts of internal antisense than the randomly assembled chains, whereas the frame two results were much higher. The internal antisense content in frame three was not significantly different from that in the random chains. The amount of internal antisense in frames two and three was correlated with the GC content at the center position of the codons in that frame, but this correlation was absent in frame one. No correlation with chain length was found. Qualitatively similar results were obtained when the random model was limited to retain the same purine/pyrimidine ratio as the native chains at each position in the codons, but in this case the internal antisense in frame three was also significantly greater than the computer-generated sequences. The results suggest that the internal antisense content in the correct reading frame has a qualitatively different origin from that in the other two frames. The high amount in frames two and three is apparently an artifact resulting from the asymmetric distribution of G and C in the codons, while the low amount in frame one may suggest evolutionary selection against internal antisense. Thus, the results do not support a relationship between internal antisense and protein structure.

Taxol and cisplatin inhibit proliferation of T47D human breast cancer cells.

We have examined the influence of taxol and cisplatin on the rate and extent of proliferation of T47D cells grown in the presence of 5% fetal bovine serum (FBS). An 8-day exposure of the cells to taxol inhibited the growth completely maintaining the number of cells to the level seen at initial plating. The taxol effect was evident at 10 nM-1 microM concentration and the half maximum inhibition was calculated to be 20 nM taxol. While the cells in the control group taxol-treated group remained at the initial number. Similar observations were made regarding the influence of cisplatin, which caused 80-90% inhibition in the number of the cells. When combined, taxol and cisplatin caused a further inhibition in the proliferation of T47D cells. The results of our studies demonstrate that both taxol and cisplatin, the known antineoplastic agents, block the proliferation of T47D human breast cancer cells effectively and are potentially useful chemotherapeutic agents for the management of breast cancer.

Suppression of Ixodes scapularis (Acari: Ixodidae) nymphs in a large residential community.

To determine the feasibility of suppressing Ixodes scapularis Say populations in a large, hyperendemic residential community, several rates of granular carbaryl were applied by ground and air to the shrub layer and wooded buffers of a forested residential community during the peak activity period of nymphs. Granular carbaryl significantly reduced the abundance of I. scapularis nymphs on Peromyscus leucopus Raphinesque. Control nymphal ticks ranged between 70.0 and 90.3%. The use of properly timed acaricide applications to I. scapularis habitat within residential communities can provide an effective means of reducing exposure to I. scapularis nymphs, which are chiefly responsible for transmitting Borrelia burgdorferi to humans.

Sweet's syndrome in children.

Acute febrile neutrophilic dermatosis (Sweet's syndrome) is a rare inflammatory disease of unknown cause characterized by painful, erythematous plaques and a dermal infiltrate of mature neutrophils. Associated systemic disease is a common finding in patients with Sweet's syndrome, and in fact determines the prognosis; therefore, the diagnosis of Sweet's syndrome warrants a thorough medical evaluation. We found only 17 reported cases of Sweet's syndrome in children. Two cases of Sweet's syndrome in children are presented; these cases are typical, except for the tibial pain in the first patient and the marked leukocytosis in the second patient. Both patients responded promptly to systemic corticosteroid therapy, although both had relapse.