Beer Consumption Increases Human Attractiveness to Malaria Mosquitoes

Background

Malaria and alcohol consumption both represent major public health problems. Alcohol consumption is rising in developing countries and, as efforts to manage malaria are expanded, understanding the links between malaria and alcohol consumption becomes crucial. Our aim was to ascertain the effect of beer consumption on human attractiveness to malaria mosquitoes in semi field conditions in Burkina Faso.

Methodology/Principal Findings

We used a Y tube-olfactometer designed to take advantage of the whole body odour (breath and skin emanations) as a stimulus to gauge human attractiveness to Anopheles gambiae (the primary African malaria vector) before and after volunteers consumed either beer (n = 25 volunteers and a total of 2500 mosquitoes tested) or water (n = 18 volunteers and a total of 1800 mosquitoes). Water consumption had no effect on human attractiveness to An. gambiae mosquitoes, but beer consumption increased volunteer attractiveness. Body odours of volunteers who consumed beer increased mosquito activation (proportion of mosquitoes engaging in take-off and up-wind flight) and orientation (proportion of mosquitoes flying towards volunteers'' odours). The level of exhaled carbon dioxide and body temperature had no effect on human attractiveness to mosquitoes. Despite individual volunteer variation, beer consumption consistently increased attractiveness to mosquitoes.

Conclusions/Significance

These results suggest that beer consumption is a risk factor for malaria and needs to be integrated into public health policies for the design of control measures.     

Measuring farmers' attitude towards breeding tools: the Livestock Breeding Attitude Scale

Under-use of genetic improvement tools and low participation in breeding programmes are key drivers of breeding programmes under-performance. Both aspects are heavily influenced by farmers attitudes which, to date, have not been analysed in an objective and systematic manner. A key factor constraining the implementation of attitudinal studies towards livestock breeding tools is the lack of a reference scale for measuring attitudes. In this research, we provide the livestock breeding sector with such a reference measure. We developed the scale following the standardized psychometric methodologies and statistical tools. Then, as a case study, we used the scale to explore the attitudes of beef and dairy sheep farmers in Australia, New Zealand and Spain and analysed farmer and farming system factors related to those attitudes. Fourteen sheep and beef breed associations facilitated the implementation of a survey of 547 farmers, generating data that was used for the scale evaluation. The relationship between attitudinal factors and farmer and farming system factors was analysed using generalized linear models across and within breeds. The results suggest that the 8-item definitive scale we have developed is appropriate to measure farmer attitudes. We found that attitudes towards genetic improvement tools have two components; i) traditional selection and ii) genetic and genomic selection combined. This means that positive attitudes towards traditional phenotypic selection do not necessarily imply a negative attitude towards genetic and genomic selection tools. Farmer attitudes varied greatly not only across the studied breeds, species and countries, but also within them. High-educated farmers of business-oriented farms tend to have the most negative attitude towards traditional selection. However, attitudes towards genetic and genomic selection tools could not be linked to these factors. Finally, we found that the breed raised had a large effect on farmer attitude. These findings may help in the evolution of breeding programmes by identifying both the farmers most inclined to uptake breeding innovations in the early stages of its establishment and the farmers who would be more reluctant to participate in such programmes, thus informing where to focus extension efforts.     

全小麦啤酒酵母菌株的诱变育种及应用研究

采用10 Kev低能N~+注入啤酒酵母,经筛选获得一菌株Lz37,再用150 MPa超高压处理菌株Lz37,经双乙酰平板筛选获得一菌株Gy3,其凝聚性很强,适合于在小麦汁中发酵啤酒,其发酵度为66%～68%,双乙酰含量低于口味阈值,遗传稳定性良好。将Gy3酵母定为全小麦啤酒生产应用酵母,命名为商啤3号(Sp-03)。SP-03啤酒酵母菌株的各项生理及生产性能都较优良,特别是在全小麦芽啤酒的酿造中适用性较强,经过对发酵工艺等的调整,用其酿制的啤酒口感纯正、淡爽、柔和。     

The Effect of Implicitly Incentivized Faking on Explicit and Implicit Measures of Doping Attitude: When Athletes Want to Pretend an Even More Negative Attitude to Doping

The Implicit Association Test (IAT) aims to measure participants’ automatic evaluation of an attitude object and is useful especially for the measurement of attitudes related to socially sensitive subjects, e.g. doping in sports. Several studies indicate that IAT scores can be faked on instruction. But fully or semi-instructed research scenarios might not properly reflect what happens in more realistic situations, when participants secretly decide to try faking the test. The present study is the first to investigate IAT faking when there is only an implicit incentive to do so. Sixty-five athletes (22.83 years ± 2.45; 25 women) were randomly assigned to an incentive-to-fake condition or a control condition. Participants in the incentive-to-fake condition were manipulated to believe that athletes with lenient doping attitudes would be referred to a tedious 45-minute anti-doping program. Attitudes were measured with the pictorial doping brief IAT (BIAT) and with the Performance Enhancement Attitude Scale (PEAS). A one-way MANOVA revealed significant differences between conditions after the manipulation in PEAS scores, but not in the doping BIAT. In the light of our hypothesis this suggests that participants successfully faked an exceedingly negative attitude to doping when completing the PEAS, but were unsuccessful in doing so on the reaction time-based test. This study assessed BIAT faking in a setting that aimed to resemble a situation in which participants want to hide their attempts to cheat. The two measures of attitude were differentially affected by the implicit incentive. Our findings provide evidence that the pictorial doping BIAT is relatively robust against spontaneous and naïve faking attempts. (B)IATs might be less prone to faking than implied by previous studies.     

Osmotic Biosensors. How to Use a Characean Internode for Measuring the Alcohol Content of Beer

Isolated internodes of Chara corallina and Nitella flexilis have been used to determine the concentration of one passively permeating solute in the presence of non-permeating solutes. The technique was based on the fact that the shape of the peaks of the biphasic responses of cell turgor (as measured in a conventional way using the cell pressure probe) depended on the concentration and composition of the solution and on the permeability and reflection coefficients of the solutes. Peak sizes were proportional to the concentration of the permeating solute applied to the cell. Thus, using the selective properties of the cell membrane as the sensing element and changes of turgor pressure as the physical signal, plant cells have been used as a new type of biosensor based on osmotic principles. Upon applying osmotic solutions, the responses of cell turgor (P) exactly followed the P(t) curves predicted from the theory based on the linear force/flow relations of irreversible thermodynamics. The complete agreement between theory and experiment was demonstrated by comparing measured curves with those obtained by either numerically solving the differential equations for volume (water) and solute flow or by using an explicit solution of the equations. The explicit solution neglected the solvent drag which was shown to be negligible to a very good approximation. Different kinds of local beers (regular and de-alcoholized) were used as test solutions to apply the system for measuring concentrations of ethanol. The results showed a very good agreement between alcohol concentrations measured by the sensor technique and those obtained from conventional techniques (enzymatic determination using alcohol dehydrogenase or from measurement of the density and refraction index of beer). However, with beer as the test solution, the characean internodes did show irreversible changes of the transport properties of the membranes leading to a shift in the responses when cells were treated for longer than 1 h with diluted beer. The accuracy and sensitivity of the osmotic biosensor technique as well as its possible applications are discussed.     

啤酒腐败微生物与啤酒微生物稳定性研究进展

尽管生产环境和卫生条件已经得到大幅改善,但啤酒生产过程中仍然会发生微生物污染,因此,真正意义上的啤酒纯种酿制是很难实现的。为了有效控制生产过程中的微生物污染,本文系统介绍了啤酒微生物的多样性及其在生产工序中的分布,探讨了啤酒环境对抑制啤酒微生物污染的影响,讨论了啤酒微生物对啤酒质量与风味的积极贡献,提出合理控制外源微生物侵染是形成不同啤酒典型特征的关键。     

Taste effects of some amino acids and glutamate compounds in the rat

Behavioral responses to five L-amino acids (Gly, Arg, Leu, Ala,Met) and five related L-glutamate compounds (MSG, MKG, MAG,Gln, GluHCl) were measured using 1-min taste reactivity andstandard 24-h, two-bottle preference tests. Taste reactivitytests measure the immediate pattern of ingestive and aversiveoral motor behavior elicited by direct oral infusion of tastestimuli. By permitting acute observations in non-deprived rats,taste reactivity tests are more sensitive to taste factors thanstandard long-term tests. Three stimulus concentrations of eachcompound were selected by behavioral and electrophysiologicalcriteria. Taste reactivity results often conflicted with standardintake results. In taste reactivity tests both Gly and MSG elicitingestive oral motor responses that increase with stimulus concentrationin the absence of aversive behavior. The opposite responseswere obtained using long-term intake tests; MSG and Gly preferenceratios actually decrease with increasing concentration. Thesedata suggest a reinterpretation of standard, longterm intaketests. Specifically, effects of taste versus post-oral stimulimay be distinguished by contrasting taste reactivity and two-bottlepreference tests. Differences in the pattern of oral motor behaviorselicited by the amino acid and glutamate compounds are alsodiscussed.     

SEGMENTATION APPROACHES THAT DIFFERENTIATE CONSUMPTION FREQUENCY FROM SENSORY PREFERENCE1

People can eat a food without having a strong preference for it, and people can prefer a food without eating it. Given this seeming disconnect between attitude and behavior, which type of measure or segment can best be used to profile or identify loyal consumer segments of a food, such as soy? This research compares a usage‐based method (heavy‐light‐nonusers) with a new attitude‐based method (seeker‐neutral‐avoider), and finds that the attitude‐based method differentiates purchase‐related intentions better than the usage‐based method. Implications for profiling consumer taste patterns and consumer segments are provided.     

Study of the preference of high probability of attaining the goal or its subjective value

The authors used testimonies of students on the dominant motives of joining a higher education institution as the behavioral model that prefers a high probability of the attainment of a goal or its subjective value. They compared the features of the motivation sphere related to the choice of profession with the psychophysiological data of 38 students of a sports higher education institution. The motivation of this choice was determined using a test questionnaire that permitted the authors to measure the subjective value (importance) and accessibility (probability of attainment) of the selected profession. The psychophysiological features were evaluated on two levels, i.e., formal dynamic (temperamental characteristics) and physiological (frequency and amplitude characteristics of EEG). The athlete students’ motivating factor of the choice of profession was shown to form under the influence of individual and typological features, which manifest themselves in psychomotor activity and total ergicity (working capacity), while accessibility experiences a negative influence of the temperamental characteristics in the intellectual sphere, as well as the total ergicity level. The background EEG was more activated in those who chose sports as their profession because of deeming it more valuable. In students who were attracted by the accessibility of this field, a lower cerebral activation level was observed, especially in the frontal zones of the left hemisphere.     

Adolescent oxytocin exposure causes persistent reductions in anxiety and alcohol consumption and enhances sociability in rats

Previous studies have suggested that administration of oxytocin (OT) can have modulatory effects on social and anxiety-like behavior in mammals that may endure beyond the time of acute OT administration. The current study examined whether repeated administration of OT to male Wistar rats (n = 48) during a key developmental epoch (early adolescence) altered their physiology and behavior in later-life. Group housed rats were given intraperitoneal injections of either 1 mg/kg OT or vehicle during early adolescence (post natal-days [PND] 33–42). OT treatment caused a transient inhibition of body weight gain that recovered quickly after the cessation of treatment. At PND 50, the rats pre-treated with OT displayed less anxiety-like behavior on the emergence test, while at PND 55 they showed greater levels of social interaction. A subgroup of OT pre-treated rats examined at PND 63 showed a strong trend towards increased plasma OT levels, and also displayed significantly increased OT receptor mRNA in the hypothalamus. Rats pre-treated with OT and their controls showed similar induction of beer intake in daily 70 min test sessions (PND 63 onwards) in which the alcohol concentration of beer was gradually increased across days from 0.44% to 4.44%. However, when given ad libitum access to beer in their home cages from PND 72 onwards (early adulthood), consumption of beer but not water was significantly less in the OT pre-treated rats. A “booster” shot of OT (1 mg/kg) given after 25 days of ad libitum access to beer had a strong acute inhibitory effect on beer intake without affecting water intake. Overall these results suggest that exogenous OT administered during adolescence can have subtle yet enduring effects on anxiety, sociability and the motivation to consume alcohol. Such effects may reflect the inherent neuroplasticity of brain OT systems and a feed-forward effect whereby exogenous OT upregulates endogenous OT systems.     

A possible role of social activity to explain differences in publication output among ecologists

Publication output is the standard by which scientific productivity is evaluated. Despite a plethora of papers on the issue of publication and citation biases, no study has so far considered a possible effect of social activities on publication output. One of the most frequent social activities in the world is drinking alcohol. In Europe, most alcohol is consumed as beer and, based on well known negative effects of alcohol consumption on cognitive performance, I predicted negative correlations between beer consumption and several measures of scientific performance. Using a survey from the Czech Republic, that has the highest per capita beer consumption rate in the world, I show that increasing per capita beer consumption is associated with lower numbers of papers, total citations, and citations per paper (a surrogate measure of paper quality). In addition I found the same predicted trends in comparison of two separate geographic areas within the Czech Republic that are also known to differ in beer consumption rates. These correlations are consistent with the possibility that leisure time social activities might influence the quality and quantity of scientific work and may be potential sources of publication and citation biases.     

Perception of sweet taste is important for voluntary alcohol consumption in mice

To directly evaluate the association between taste perception and alcohol intake, we used three different mutant mice, each lacking a gene expressed in taste buds and critical to taste transduction: α-gustducin ( Gnat3 ), Tas1r3 or Trpm5 . Null mutant mice lacking any of these three genes showed lower preference score for alcohol and consumed less alcohol in a two-bottle choice test, as compared with wild-type littermates. These null mice also showed lower preference score for saccharin solutions than did wild-type littermates. In contrast, avoidance of quinine solutions was less in Gnat3 or Trpm5 knockout mice than in wild-type mice, whereas Tas1r3 null mice were not different from wild type in their response to quinine solutions. There were no differences in null vs. wild-type mice in their consumption of sodium chloride solutions. To determine the cause for reduction of ethanol intake, we studied other ethanol-induced behaviors known to be related to alcohol consumption. There were no differences between null and wild-type mice in ethanol-induced loss of righting reflex, severity of acute ethanol withdrawal or conditioned place preference for ethanol. Weaker conditioned taste aversion (CTA) to alcohol in null mice may have been caused by weaker rewarding value of the conditioned stimulus (saccharin). When saccharin was replaced by sodium chloride, no differences in CTA to alcohol between knockout and wild-type mice were seen. Thus, deletion of any one of three different genes involved in detection of sweet taste leads to a substantial reduction of alcohol intake without any changes in pharmacological actions of ethanol.     

Reduced urination rate while drinking beer with an unpleasant taste and off-flavor

A lowered subjective evaluation of the taste and flavor of beer due to staleness or to the addition of an unpleasant taste and flavor was found to be closely correlated with the urination rate. Beer in the same lot was compared immediately after shipment from the brewery and after leaving at room temperature for 1 month or 5 months. Each beer sample was given to volunteers at the rate of 3 ml/kg/15 min for 2 hours, and the urine volume was measured every 30 minutes. The urination rate was highest from the volunteers who drank fresh beer and lowest from those who drank 5-month-old beer. The subjective evaluation of both the taste and drinkability of 5-month-old beer was significantly lower than that of fresh beer. Beer samples with various unpleasant taste and flavor substances added lowered the urination rate. The results suggest that the perception of an unpleasant taste and off-flavor would lower the urination rate.     

Obese Women Have Lower Monosodium Glutamate Taste Sensitivity and Prefer Higher Concentrations Than Do Normal‐weight Women

The goal of this study was to determine whether obese women exhibit altered umami and sweet taste perception compared to normal‐weight women. A total of 57 subjects (23 obese and 34 normal weight) participated in a 2‐day study separated by 1 week. Half of the women in each group were evaluated using monosodium glutamate (MSG; prototypical umami stimulus) on the first test day and sucrose on the second test day; the order was reversed for the remaining women. We used two‐alternative forced‐choice staircase procedures to measure taste detection thresholds, forced‐choice tracking technique to measure preferences, the general Labeled Magnitude Scale (gLMS) to measure perceived intensity of suprathreshold concentrations, and a triangle test to measure discrimination between 29 mmol/l MSG and 29 mmol/l NaCl. Obese women required higher MSG concentrations to detect a taste and preferred significantly higher MSG concentrations in a soup‐like vehicle. However, their perception of MSG at suprathreshold concentrations, their ability to discriminate MSG from salt, and their preference for sucrose were similar to that observed in normal‐weight women. Regardless of their body weight category, 28% of the women did not discriminate 29 mmol/l MSG from 29 mmol/l NaCl (nondiscriminators). Surprisingly, we found that, relative to discriminators, nondiscriminators perceived less savoriness when tasting suprathreshold MSG concentrations and less sweetness from suprathreshold sucrose concentrations but had similar MSG and sucrose detection thresholds. Taken together, these data suggest that body weight is related to some components of umami taste and that different mechanisms are involved in the perception of threshold and suprathreshold MSG concentrations.     

Effect of Selected Types of Beer on Bacteria of the Genus Arcobacter

The genus Arcobacter is related to the well-known human pathogen, Campylobacter jejuni, and has been linked to human diseases. In this study, the survival of Arcobacter spp. in various concentrations of ethanol, in various samples of beers, and in a model stomach has been investigated. For most of these bacteria, a concentration of 10 % ethanol was determined to be the minimum inhibitory concentration. The fact that these organisms are able to survive under these conditions may have an impact in the food processing industry. We studied the activity of beer against arcobacters. These bacteria were killed in all samples of beer within 30 min. A model stomach, containing a food matrix and a synthetic gastric fluid, was used to deduce the effect of beer against Arcobacter spp. during food consumption. Complete inactivation of all monitored arcobacters was detected usually within 15 min. However, the presence of beer does not potentiate the effect of gastric fluid against these bacteria. This is apparently the first study focusing upon the effect of beer on Arcobacter spp.     

Beer increases plasma antioxidant capacity in humans

The positive association of a moderate intake of alcoholic beverages with a low risk for cardiovascular disease, in addition to ethanol itself, may be linked to their polyphenol content. This article describes the effect of acute ingestion of beer, dealcoholized beer, and ethanol (4.5% v/v) on the total plasma antioxidant status of subjects, and the change in the high performance liquid chromatography profile of some selected phenolic acids (caffeic, sinapic, syringic, and vanillic acids) in 14 healthy humans. Plasma was collected at various times: before (T0), 1 hour after (T1), and 2 hours after (T2) drinking. The study is part of a larger research planned to identify both the impact of brewing on minor components potentially present in beer and their metabolic fate in humans. Beer was able to induce a significant (P < 0.05) increase in plasma antioxidant capacity at T1 (mean +/- SD: T0 1,353 +/- 320 microM; T1 1,578 +/- 282 microM), returning close to basal values at T2. All phenolic acids measured in plasma tended to increase after beer intake (20% at T1, 40% at T2). Syringic and sinapic acid reached statistical significance (P < 0.05 by one-way analysis of variance-Fisher's test) at T1 and T2, respectively. Plasma metabolic parameters (glucose, total cholesterol, triglycerides, and uric acid) and plasma antioxidants (alpha-tocopherol and glutathione) remained unchanged. Ethanol removal impaired the absorption of phenolic acids, which did not change over the time of the experiment, accounting for the low (and not statistically significant) increase in plasma antioxidant capacity after dealcoholized beer drinking. Ethanol alone did not affect plasma antioxidant capacity or any of the antioxidant and metabolic parameters measured.     

野生动物肇事补偿对社区居民态度改变的作用及机制——以四川卧龙国家级自然保护区为例

野生动物肇事补偿是缓和人与野生动物冲突的常用措施之一,其核心目的是补偿社区居民的经济损失并最终改善社区居民对于肇事动物的态度,实现人与野生动物的和谐共处。以四川卧龙国家级自然保护区为例,研究了目前以及假设补偿后社区居民态度的变化及其影响因素和作用机制。在对态度进行多维特征划分的基础上,使用Wilcoxon秩和检验、二元logistic回归模型等方法探究野生动物肇事补偿对社区居民态度改变的作用以及影响因素。研究发现：野生动物肇事补偿可显著改变社区居民对于肇事动物的态度,且均发生了积极的改变,但对不同维度态度的改变作用不同。其中,喜厌态度的改变最明显,其次是捕杀态度和保护态度,最后是期望态度。肇事补偿对于社区居民的态度及其改变作用受到其社会经济特征的影响,其中是否受到过野生动物破坏、耕作总收入或总收入中耕作收入比重以及受教育程度显著影响社区居民的态度,农地总面积、牲畜数量、玉米地面积会显著影响社区居民情感态度的改变,玉米地损失面积会显著影响社区居民行为态度的改变。论文进一步讨论了各个影响因素的作用机制,并根据研究结果提出了普及肇事补偿制度、完善肇事补偿机制、调整生计策略和种植结构、通过多种...     

Electrophysiological Responses to Alcohol Cues Are Not Associated with Pavlovian-to-Instrumental Transfer in Social Drinkers

Pavlovian to Instrumental Transfer (PIT) refers to the behavioral phenomenon of increased instrumental responding for a reinforcer when in the presence of Pavlovian conditioned stimuli that were separately paired with that reinforcer. PIT effects may play an important role in substance use disorders, but little is known about the brain mechanisms that underlie these effects in alcohol consumers. We report behavioral and electroencephalographic (EEG) data from a group of social drinkers (n = 31) who performed a PIT task in which they chose between two instrumental responses in pursuit of beer and chocolate reinforcers while their EEG reactivity to beer, chocolate and neutral pictorial cues was recorded. We examined two markers of the motivational salience of the pictures: the P300 and slow wave event-related potentials (ERPs). Results demonstrated a behavioral PIT effect: responding for beer was increased when a beer picture was presented. Analyses of ERP amplitudes demonstrated significantly larger slow potentials evoked by beer cues at various electrode clusters. Contrary to hypotheses, there were no significant correlations between behavioral PIT effects, electrophysiological reactivity to the cues, and individual differences in drinking behaviour. Our findings are the first to demonstrate a PIT effect for beer, accompanied by increased slow potentials in response to beer cues, in social drinkers. The lack of relationship between behavioral and EEG measures, and between these measures and individual differences in drinking behaviour may be attributed to methodological features of the PIT task and to characteristics of our sample.     

Relationships between and among selected measures of sweet-taste preference and dietary intake

The extent to which the sensory properties of foods influencedietary practices remains poorly characterized. Hedonic attributesappear to exert the predominant role among sensory factors.Therefore a parametric study to ascertain the relationshipsbetween measures of sweet-taste preferences and selected relevantdietary measures was undertaken. Twenty-five healthy, normalweight adults kept 7-day diet records and provided hedonic responsesto (i) lists of foods on questionnaires, (ii) prepared coffeeand oatmeal samples on category and visual analog scales, and(iii) water and coffee via an adjustment task. Ratings wereobtained under conditions where samples were swallowed versusexpectorated and viewed as ‘normal foods’ versus‘test samples’. Correlations were then sought betweendietary variables and both individual and aggregate profilesof preference measures. Either analytic approach revealed significantassociations with estimates of preferred tastes of the diet,but only taste profiles comprised of several taste preferencemeasures together were significantly related to nutrient intake(i.e. carbohydrate and alcohol calories). This observation,as well as findings obtained from the different testing proceduresand contexts, are considered from a methodologic perspective(i.e. what are the optimal conditions for examining diet–tasterelationships).     

Quantitative Evaluation of Sunstruck Flavor of Beer

Judgement of sunstruck flavor of beer has been relying on the sensory evaluation. However, this sensory test is inaccurate, as well known. Utilizing the experimental result that sunstruck flavor is caught completely with silver nitrate, the authors established a potentiometric method for the determination of sunstruck flavor substance of beer by expressing its intensity in the amount of silver ions combined with it.