Modification of the bitterness of caffeine

Caffeine is the worlds most consumed psychoactive chemical and as such is a valuable commodity to the food and beverage industry. Caffeine also activates the bitter taste system causing a potential problem for manufacturers wanting to develop products containing caffeine. In the present study both oral peripheral and central cognitive strategies were used in an attempt to suppress the bitterness of caffeine. Subjects (n = 33) assessed the influence of sodium gluconate (100 mM), zinc lactate (5 mM), sucrose (125 mM and 250 mM), milk (0%, 2% and 4% milk fat), and aromas (coffee, chocolate, mocha) on the bitterness of caffeine (1.5, 3 and 4.5 mM). The oral peripheral strategies proved most effective at suppressing the bitterness of caffeine: zinc lactate (−71%, p < 0.05), non-fat milk (−49%, p < 0.05), and sodium gluconate (−31%). Central cognitive strategies were partially effective: 250 mM sucrose (−47%, p < 0.05) and mocha aroma (−10%) decreased bitterness, while chocolate (+32%) and coffee (+17%) aromas increased perceived bitterness. Overall, zinc lactate was the most effective bitterness inhibitor, however the utility of zinc in foods is negated by its ability to inhibit sweetness.

Modification of the visual background increases the conspicuousness of golden-collared manakin displays

Effective visual communication requires signals that are easy to detect, transmit, receive, and discriminate. Animals can increase the probability that their visual signals would be detected by evolving signals that contrast with their visual background. Animals can further enhance this contrast by behaviorally modifying the existing visual background. Male golden-collared manakins (Manacus vitellinus) clear leaf litter from the ground to form courts, which are used as display arenas. Using reflectance measures of the signal (male plumage) and the visual background (cleared court and adjacent litter), the irradiance measures of ambient light during display, and published measures of photoreceptor sensitivity of a Passerine, we test the hypothesis that court-clearing augments the contrast between male plumage and the visual background. We find that the chromatic and brightness contrasts of golden patches used during courtship are greater against the cleared court than against adjacent litter. In addition, we find that cleared courts provide a less variable background for these color patches, resulting in displays that consistently contrast the visual background. These results suggest that behavioral modification of the visual background may act to increase the conspicuousness of colorful male plumage during display, providing an explanation for why golden-collared manakins, and possibly other species, build or clear display courts.

Functional similarities between pigeon 'milk' and mammalian milk : induction of immune gene expression and modification of the microbiota

Pigeon ‘milk’ and mammalian milk have functional similarities in terms of nutritional benefit and delivery of immunoglobulins to the young. Mammalian milk has been clearly shown to aid in the development of the immune system and microbiota of the young, but similar effects have not yet been attributed to pigeon ‘milk’. Therefore, using a chicken model, we investigated the effect of pigeon ‘milk’ on immune gene expression in the Gut Associated Lymphoid Tissue (GALT) and on the composition of the caecal microbiota. Chickens fed pigeon ‘milk’ had a faster rate of growth and a better feed conversion ratio than control chickens. There was significantly enhanced expression of immune-related gene pathways and interferon-stimulated genes in the GALT of pigeon ‘milk’-fed chickens. These pathways include the innate immune response, regulation of cytokine production and regulation of B cell activation and proliferation. The caecal microbiota of pigeon ‘milk’-fed chickens was significantly more diverse than control chickens, and appears to be affected by prebiotics in pigeon ‘milk’, as well as being directly seeded by bacteria present in pigeon ‘milk’. Our results demonstrate that pigeon ‘milk’ has further modes of action which make it functionally similar to mammalian milk. We hypothesise that pigeon ‘lactation’ and mammalian lactation evolved independently but resulted in similarly functional products.

Controlled modification of the inorganic and organic bricks in an Al-based MOF by direct and post-synthetic synthesis routes

Four new porous CAU-1 derivatives CAU-1–NH2 ([Al4(OH)2(OCH3)4(BDC–NH2)3]·xH2O, BDC–NH22− = aminoterephthalate), CAU-1–NH2(OH) ([Al4(OH)6(BDC–NH2)3]·xH2O), CAU-1–NHCH3 ([Al4(OH)2(OCH3)4(BDC–NHCH3)3]·xH2O) and CAU-1–NHCOCH3 ([Al4(OH)2(OCH3)4(BDC–NHCOCH3)3]·xH2O) all containing an octameric [Al8(OH)4+y(OCH3)8−y]12+ cluster, with y = 0–8, have been obtained by MW-assisted synthesis and post-synthetic modification. The inorganic as well as the organic unit can be modified. Heteronuclear 1H–15N, 1H–13C and homonuclear 1H–1H connectivities determined by solid-state NMR spectroscopy prove the methylation of the NH2 groups when conventional heating is used. Varying reaction times and temperatures allow controlling the degree of methylation of the amino groups. Short reaction times lead to non-methylated CAU-1 (CAU-1–NH2), while longer reaction times result in CAU-1–NHCH3. CAU-1–NH2 can be modified chemically by using acetic anhydride, and the acetamide derivative CAU-1–NHCOCH3 is obtained. Thermal treatment permits us to change the composition of the Al-containing unit. Methoxy groups are gradually exchanged by hydroxy groups at 190 °C in air. Solid-state NMR spectra unequivocally demonstrate the presence of the amino groups, as well as the successful post-synthetic modification. Furthermore 1H–1H correlation spectra using homonuclear decoupling allow the orientation of the NHCOCH3 groups within the pores to be unravelled. The influence of time and temperature on the synthesis of CAU-1 was studied by X-ray powder diffraction, elemental analyses, and 1H liquid-state NMR and IR spectroscopy.

Modification of the National Inpatient Medication Chart improves venous thromboembolism prophylaxis rates in high-risk medical patients

Background : Venous thromboembolism (VTE) is a significant contributor to morbidity and mortality in Australia. While there is well-established evidence for the use of VTE prophylaxis in hospital inpatients, adherence to such guidelines is poor. Aim : The aim of the present study is to assess the impact of education and system change on improving rates of VTE prophylaxis in hospital inpatients. Methods : We performed four consecutive audits of inpatient medical records of a regional hospital service over 2 years. The audits aimed to test the impact of serial interventions at increasing the appropriate use of VTE prophylaxis (based on risk assessment). The interventions were (i) staff education and (ii) a process change that mandated a prophylaxis decision by modifying the National Inpatient Medication Chart with ‘VTE avoidance’ preprinted in the first medication box. Results : Our results from the baseline study showed that of the 236 medical inpatients reviewed, 80% were at high risk of VTE. Of this high-risk cohort, 34.9% (confidence interval (CI) 28–42%) had appropriate prophylaxis decisions. Post the education intervention, 43.2% (CI 37–49%) of the high-risk cohort received appropriate VTE prophylaxis, an improvement of 8.3% (CI −1% to 18%) from baseline. With the subsequent introduction of a process change, 82.1% (CI 66–92%) of the high-risk cohort received appropriate prophylaxis, an improvement of 47.2% and 38.8% (CI 24–54%) when compared with baseline and education respectively. Retention rates at 11 months postsystem change were 73% (CI 55–86%). Conclusions : This study therefore concluded that while education has an impact on rates of appropriate VTE prophylaxis, it is system change that has the most marked and sustained effect.

Superhydrophobic modification of polyimide films based on gold-coated porous silver nanostructures and self-assembled monolayers

We present a facile and effective method for controlling the surface hydrophobicity of polyimide films from sticky to superhydrophobic properties by tailoring their topographies. Nanostructured silver layers were produced on polyimide films by treatment with aqueous KOH and AgNO3, followed by thermal treatment at 200 degrees C or higher temperatures. Further modification of the gold-coated silver layers with n-dodecanethiol led to hydrophobic surfaces. Different morphologies of the silver layers at the micro- and nano-meter scales, which result in the variety of hydrophobicity, can be tailored by controlling the thermal treatment temperature. Surfaces prepared at 320 degrees C showed a sticky property that water drops did not slide off even when the sample was held upside down. Superhydrophobic surfaces were obtained when the temperature was above 340 degrees C. A remarkable superhydrophobicity, as evidenced by a very large water contact angle of 162 degrees and a very small sliding angle of 7 degrees, was achieved by heating the modified polyimide films at 360 degrees C. This is also the first example for superhydrophobic modification of polyimide films.

Comparison of the traditional problem-based learning format and larger, directed, independent study groups

 Problem based learning has been implemented as a pedagogical tool world-wide across a range of health professions since its inception at McMaster University, Canada, in 1969 (Neville & Norman, 2007). In addition to enhancing knowledge and understanding it is also claimed that PBL develops communication skills, encourages teamwork, sharing of information and respect for others, furthers problem solving skills, and allows students to assume responsibility for their own learning (Wood, 2003). However, the cognitive outcomes of PBL and traditional pedagogy (based on didactic teaching) are similar and hence widespread adoption of PBL has been questioned (see Colliver, 2000). Criticisms of PBL include its resource hungry nature, requiring, as it does, experienced tutors to facilitate .learning across several clusters of students dealing with the same problem. Given the actual and anticipated increase in numbers of medical students in Australia other strategies that retain the advantages of PBL, while minimising the demands on faculty, should now be explored. This paper reports our experience with a modification of the traditional PBL approach, termed PBLplus. This innovation was trialled in a regional clinical school, attached to a hospital, with a group of 19 graduate entry students, who had completed an integrated Year 1 / 2 of the MBBS. PBLplus involved allocating students from the whole class to three task directed groups. Groups had specified assignments to complete to facilitate learning across the whole class. A tutor listened to student presentations and provided an interactive presentation. Hence use of tutors was made more efficient, and faculty input was more specialised.

What are the origins of shamanic journeying imagery? The modification of a hypnoanalytic technique to address an enduring methodological problem

Shamanic journeying imagery arguably transcends geographical space and historical time. However, to what extent is the content of the journeying imagery a construction of the shaman's cultural cosmology, belief systems, autobiographical memories, etc? It is suggested that attempts to answer this question are hampered by a fundamental methodological obstacle: how to detect contextual influences on imagery that the shaman cannot report on because they are outside his/her present awareness and memory. A partial solution is presented: Watkins' (1971) Affect Bridge, a hypnoanalytic technique used to uncover the origin of an affect. A nonhypnotic version of the technique developed for inquiry into shamanic journeying imagery is then explicated. Two recent empirical studies conducted by Rock (2006) and Rock, Casey and Baynes (2006), illustrating the utility of the Modified Affect Bridge with regards to investigating experimentally the origin of ostensibly shamanic journeying imagery reported by naive participants, are summarized. A tentative ostensibly shamanic journeying imagery origin typology is formulated and suggestions for future research are advanced.

Chemical modification of timber decking : assessing the parameters of acceptability

The criteria for accepting or rejecting a technology extend beyond the intrinsic properties of the finished product such as physical performance. There are also extrinsic factors such as the history of the product and trust in the manufacturers and suppliers, as well as the perceptions and risk management strategies of various stakeholder groups. A methodology was trialled to take into account the extended supply chain of the product, while simultaneously engaging stakeholders to determine and to understand their perceptual frameworks. Three pine decking products manufactured using different amounts and types of chemical modification were compared using life cycle assessment and the comments of 114 respondents from six stakeholder groups in New Zealand. The results of the perceptual research include a quadrant diagram which allows a visual comparison of the responses of different stakeholders to actual or hypothetical products, aiding the identification of when and why certain technologies may be disqualified from acceptability or become the topic of public debate.

Chemical modification of timber decking: looking to the future

To help avoid conflict and even market rejection, the design and introduction of new technologies can be aided by consideration of the potential concerns of different stakeholder groups. An assessment of their desired goals for technological change may be useful for pre-empting changes in the  parameters of acceptability for technologies. As part of a research  programme evaluating the parameters of acceptability for bio-based  technologies using life cycle assessment of products and an analysis of the  perceptual frameworks of stakeholders, respondents from four stakeholder  groups in New Zealand were interviewed about the desirable and  undesirable trajectories for chemical modification technologies. Three  examples of pine decking products derived using different amounts and  types of chemical modification served to help explore the contemporary  criteria and rationale for acceptability. The responses of the 70 respondents  in those four groups indicated that new technologies need to be able to  prove their worth with regard to both tangible and intangible qualities if they  are to be accepted into the market in the place of either the existing product  or an inorganic competitor.

The self-assembled monolayer modification of electrodes - some recent advances in biological application

The modification of an electrode surface at the molecular level using the technique of depositing self-assembled monolayers (SAM) is a typical example of the techniques used in nanotechnology, from the process "bottom up", which is to create a nanostructure by successive additions of molecular or atomic entities on a surface. This article presents some recent advances in the field, with examples: the development of systems Sat hybridized with biomolecules, nanoparticles or nanotubes in bioelectronics, the use of switchable electrodes to study the adhesion and migration of biological cells , and the integration of molecular son in the SAM to recognize and allow the transduction of a biological response allowing the practice of electrochemistry in a complex biological environment.

Nonadditivity of faradaic currents and modification of double layer capacitance in the voltammetry of mixtures of ferrocene and ferrocenium salts in ionic liquids

Electrochemical studies on the Fc + e− Fc+ (Fc = ferrocene) process have been undertaken via the oxidation of Fc and reduction of Fc+ as the hexafluorophosphate (PF6−) or tetrafluoroborate (BF4−) salts and their mixtures in three ionic liquids (ILs) (1-butyl-1-methylpyrrolidinium bis[(trifluoromethyl)sulfonyl]imide, 1-butyl-3-methylimidazolium tetrafluoroborate, and 1-butyl-3-methylimidazolium hexafluorophosphate). Data obtained at macro- and microdisk electrodes using conventional dc and Fourier-transformed large-amplitude ac (FT-ac) voltammetry reveal that diffusion coefficients for Fc and Fc+ differ significantly and are a function of the Fc and Fc+ concentration, in contrast to findings in molecular solvents with 0.1 M added supporting electrolyte media. Thus, the Faradaic currents associated with the oxidation of Fc (Fc0/+) and reduction of FcPF6 or FcBF4 (Fc+/0) when both Fc and Fc+ are simultaneously present in the ILs differ from values obtained when individual Fc and Fc+ solutions are used. The voltammetry for both the Fc0/+ and Fc+/0 processes exhibited near-Nernstian behavior at a glassy carbon macrodisk electrode and a platinum microdisk electrode, when each process was studied individually in the ILs. As expected, the reversible formal potentials (E°′) and diffusion coefficients (D) at 23 ± 1 °C were independent of the electrode material and concentration. However, when Fc and FcPF6 or FcBF4 were both present, alterations to the mass transport process occurred and apparent D values calculated for Fc and Fc+ were found to be about 25−39% and 32−42% larger, respectively, than those determined from individual solutions. The apparent value of the double layer capacitance determined by FT-ac voltammetry from individual and mixed Fc and Fc+ conditions at the GC electrode was also a function of concentration. Double layer capacitance values increased significantly with the concentration of Fc and FcPF6 or FcBF4 when species were studied individually or simultaneously, but had a larger magnitude under conditions where both species were present. Variation in the structure of the ILs and hence mobilities of the ionic species, when Fc and FcPF6 or FcBF4 are simultaneously present, is considered to be the origin of the nonadditivity of the Faradaic currents and variation in capacitance.