NMR studies of calcium-binding to mutant alpha-spectrin EF-hands

The co-operative calcium binding mechanism of the two C-terminal EF-hands of human alphaII-spectrin has been investigated by site-specific mutagenesis and multi-dimensional NMR spectroscopy. To analyse the calcium binding of each EF-hand independently, two mutant structures (E33A and D69S) of wild type alpha-spectrin were prepared. According to NMR analysis both E33A and D69S were properly folded. The unmutated EF-hand in these mutants remained nearly intact and active in calcium binding, whereas the mutated EF-hand lost its affinity for calcium completely. The apparent calcium binding affinity of the E33A mutant was much lower compared to the D39S mutant (approximately 2470 microM and approximately 240 microM, respectively). When the chemical shift perturbations were followed upon calcium titration, a positive correlation between the D69S mutant and the binding of the first calcium ion to the wild type was revealed. These observations showed that the first EF-hand in spectrin binds the first calcium ion and thereby triggers a conformational change that allows the second calcium ion to bind to the other EF-hand.     

Utilitarianism and the pandemic

There are no egalitarians in a pandemic. The scale of the challenge for health systems and public policy means that there is an ineluctable need to prioritize the needs of the many. It is impossible to treat all citizens equally, and a failure to carefully consider the consequences of actions could lead to massive preventable loss of life. In a pandemic there is a strong ethical need to consider how to do most good overall. Utilitarianism is an influential moral theory that states that the right action is the action that is expected to produce the greatest good. It offers clear operationalizable principles. In this paper we provide a summary of how utilitarianism could inform two challenging questions that have been important in the early phase of the pandemic: (a) Triage: which patients should receive access to a ventilator if there is overwhelming demand outstripping supply? (b) Lockdown: how should countries decide when to implement stringent social restrictions, balancing preventing deaths from COVID-19 with causing deaths and reductions in well-being from other causes? Our aim is not to argue that utilitarianism is the only relevant ethical theory, or in favour of a purely utilitarian approach. However, clearly considering which options will do the most good overall will help societies identify and consider the necessary cost of other values. Societies may choose either to embrace or not to embrace the utilitarian course, but with a clear understanding of the values involved and the price they are willing to pay.     

The Mesh of Civilizations in the Global Network of Digital Communication

Conflicts fueled by popular religious mobilization have rekindled the controversy surrounding Samuel Huntington’s theory of changing international alignments in the Post-Cold War era. In The Clash of Civilizations, Huntington challenged Fukuyama’s “end of history” thesis that liberal democracy had emerged victorious out of Post-war ideological and economic rivalries. Based on a top-down analysis of the alignments of nation states, Huntington famously concluded that the axes of international geo-political conflicts had reverted to the ancient cultural divisions that had characterized most of human history. Until recently, however, the debate has had to rely more on polemics than empirical evidence. Moreover, Huntington made this prediction in 1993, before social media connected the world’s population. Do digital communications attenuate or echo the cultural, religious, and ethnic “fault lines” posited by Huntington prior to the global diffusion of social media? We revisit Huntington''s thesis using hundreds of millions of anonymized email and Twitter communications among tens of millions of worldwide users to map the global alignment of interpersonal relations. Contrary to the supposedly borderless world of cyberspace, a bottom-up analysis confirms the persistence of the eight culturally differentiated civilizations posited by Huntington, with the divisions corresponding to differences in language, religion, economic development, and spatial distance.Have social media created a global village that spans cultural differences and traditional borders? For most of the postwar period, research on international alignments was informed by World Systems Theory, an approach that emphasized the influence of North-South economic divisions and East-West ideological divisions [1]. Following the collapse of the Soviet Union, Fukuyama [2] proposed that those divisions had culminated in the triumph of liberal democratic systems, signaling the “end of history.” In The Clash of Civilizations [3], Fukuyama’s mentor, Samuel Huntington, acknowledged that “the fundamental source of conflict in this new world will not be primarily ideological or primarily economic,” but he challenged Fukyama’s prediction of global consensus:The great divisions among humankind and the dominating source of conflict will be cultural. Nation states will remain the most powerful actors in world affairs, but the principal conflicts of global politics will occur between nations and groups of different civilizations. The clash of civilizations will dominate global politics. The fault lines between civilizations will be the battle lines of the future.The world has undergone substantial changes since Huntington made this prediction in 1993, including rapid economic growth in South Asia and South America and global diffusion of social media connecting the world’s population. Moreover, the evidence for Huntington''s theory of international global alignment was largely top-down, based on the political and economic relations among culturally differentiated nation states. The growing availability of digital traces of human communications now makes it possible to revisit Huntington''s thesis by taking a bottom-up view, based on interpersonal interactions among millions of individuals instead of the alignments of state actors. Have these online interactions created a global village that spans not only the old Cold War divisions but Huntington’s cultural fault lines as well?To find out, we used hundreds of millions of anonymized email and Twitter communications among tens of millions of worldwide users to map global patterns of transnational interpersonal communication. We measure the density, not the content, of interpersonal communication, and our findings do not address Huntington’s highly controversial warning of the potential for conflict between cultures. Nevertheless, the observed patterns provide a unique angle on changing global alignments in the Post-Cold War era.Our work builds on a study by Leskovec and Horvitz of the global flows of online Instant Messaging (IM) [4], extending that research in four important ways. First, we measure the density of social ties, not the density of message traffic. The “fault lines of civilizations” are indicated not by the number of messages two people exchange across borders but by the number of individuals in each country who exchange messages with one another. Second, we measure the density of social ties after taking into account differences in language, geo-location, Cold War alignment, economic development, and religion. (NB: In addition to analyzing communication densities between country pairs, Leskovec and Horvitz also measured global properties of the social network among pairs of individuals, but they did not use the latter to analyze social densities between country pairs. They also found that between-country communication densities were highly correlated with language and spatial distance, but they did not measure communication densities relative to the expected density given similarities of language and geo-location.) Third, we use multiple platforms (Yahoo! email and Twitter) to provide greater robustness and to avoid the possibility that our results are artifacts of the idiosyncrasies of a particular service. Twitter differs from email in two ways that are relevant to our study: most email exchanges are dyadic while Twitter messages are publicly visible, and the Twitter platform makes it much easier for users to discover one another, thereby reducing the tendency for online interactions to reflect pre-existing relationships. Fourth, we correct for internet access and market penetration, without which online traffic flows confound the strength of interpersonal ties with the popularity of a given communication medium. By taking into account differences in Internet access and market penetration, we are able to estimate the global network of social ties derived from the interpersonal flows of Internet communications.We measured communication density based on the number of observed bi-directed ties between users in two countries, relative to the maximum possible number of such ties, given the number of users in each country and the number of people with Internet access. (NB: The email analysis was based on anonymized geo-tagged edge lists. Prior to the analysis, the edge lists were anonymized as follows: Individual email accounts were assigned a random numeric identifier, after which the original email addresses were deleted. The email message content was not accessed or used for this study. Other than country, the edge lists we analyzed contained no individually identifiable information. The project was approved by the Cornell University IRB. The Twitter dataset was provided to us already anonymized by the team that collected it [5]. Scripts for the processing of that dataset are available from http://dx.doi.org/10.6084/m9.figshare.1304572.)A bi-directed email tie exists between two users if at least two messages are exchanged, one in each direction. A bi-directed Twitter tie exists if two users each follow the other. We defined pairwise communication density as the ratio between the observed number of bi-directed ties and the number of expected ties, given the number of subscribers and the number of Internet users.We obtained qualitatively similar results for email and Twitter communication densities and therefore report only the combined density measures for the two platforms. We also measured densities net of geographic proximity, shared language, population size, economic development, and colonial history.     

Strategies for Improving Participation in Diabetes Education. A Qualitative Study

Objective

Diabetes mellitus is highly prevalent and can lead to serious complications and mortality. Patient education can help to avoid negative outcomes, but up to half of the patients do not participate. The aim of this study was to analyze patients'' attitudes towards diabetes education in order to identify barriers to participation and develop strategies for better patient education.

Methods

We conducted a qualitative study. Seven GP practices were purposively selected based on socio-demographic data of city districts in Hamburg, Germany. Study participants were selected by their GPs in order to increase participation. Semi-structured face-to-face interviews were conducted with 14 patients. Interviews were audiotaped and transcribed verbatim. The sample size was determined by data saturation. Data were analysed by qualitative content analysis. Categories were determined deductively and inductively.

Results

The interviews yielded four types of barriers: 1) Statements and behaviour of the attending physician influence the patients'' decisions about diabetes education. 2) Both, a good state of health related to diabetes and physical/psychosocial comorbidity can be reasons for non-participation. 3) Manifold motivational factors were discussed. They ranged from giving low priority to diabetes to avoidance of implications of diabetes education as being confronted with illness narratives of others. 4) Barriers also include aspects of the patients'' knowledge and activity.

Conclusions

First, physicians should encourage patients to participate in diabetes education and argue that they can profit even if actual treatment and examination results are promising. Second, patients with other priorities, psychic comorbidity or functional limitations might profit more from continuous individualized education adapted to their specific situation instead of group education. Third, it might be justified that patients do not participate in diabetes education if they have slightly increased blood sugar values only and no risk for harmful consequences or if they already have sufficient knowledge on diabetes.     

Jaw musculature during the dawn of turtle evolution

Using a new approach to study muscle anatomy in vertebrates, the fully differentiated jaw musculature of 42 turtle species was studied and character mappings were performed. Soft tissue arrangements were correlated to the temporal openings (emarginations) of the skull and the trochlearis system of the jaw apparatus among turtle taxa. When compared to the cranial anatomy of stem Testudines, most characters detected as diagnostic of particular extant groups have to be considered as being evolved first within Testudines. Hence, jaw muscle anatomy of extant turtles is difficult to compare to that of other reptilian taxa. Moreover, the high number of apomorphic character changes speaks for a divergating turtle and saurian morphotype of jaw musculature, which could indicate either a position of turtles outside of Sauria or a highly derived, undetectable origin within that group. In general, a low direct correlation of most soft and hard tissue characters was detected. This finding could imply that both character complexes are more integrated to each other driven by functional morphology; i.e., the composition of muscle fibre types. That condition highlights the difficulty in using gross anatomy of jaw muscle characters to interpret temporal bone arrangements among amniotes in general.     

Status and needs for online control of tertiary ozone-based water treatment: use of surrogate correlation models for removal of trace organic contaminants

The number of studies dealing with tertiary ozonation to remove trace organic contaminants (TrOCs) in effluents originating from wastewater treatment plants (WWTPs) is increasing due to the need for upgrading the WWTPs overall performance. To follow-up TrOCs removal in real-time during ozone-based treatment, online surrogate measurements are necessary, of which mainly spectroscopic surrogates (i.e. UV–VIS absorbance and fluorescence) are the emerging techniques in literature. This paper summarizes and reflects on the state-of-the-art as retrieved from more than 100 peer-reviewed studies published between January 2007 and December 2020 and dealing with (1) surrogate correlation models for the prediction of TrOCs removal in secondary effluent and (2) control strategies to adjust the ozone dose during (full-scale) operation. Next to the flow and load proportional ozone dosing strategies, controlling the ozone dose solely based on the characteristics of the effluent entering the ozonation unit, also a differential control strategy based on the change in characteristics due to ozonation of the WWTP effluent is highlighted. The latter seems the best option as flow and load proportional ozone dosing do not consider the amount and/or reactivity of the matrix constituents. The presence of organic and inorganic scavengers of ozone and radicals in the effluent matrix has a significant impact on the TrOCs removal efficiency. This effluent quality can differ in time and between WWTPs, hence the surrogate correlation models should be widely applicable. At the end of the review, recommendations are made for future research and implementation of an effective control strategy for (full-scale) applications.

     

Esophageal cancer proliferation is mediated by cytochrome P450 2C9 (CYP2C9)

Cytochrome P450 epoxygenases (CYP450) have been recently shown to promote malignant progression. Here we investigated the mRNA and protein expression and potential clinical relevance of CYP2C9 in esophageal cancer. Highest expression was detected in esophageal adenocarcinoma (EAC; n=78) and adjacent esophageal mucosa (NEM; n=79). Levels of CYP2C9 in EAC and NEM were significantly higher compared to esophageal squamous cell carcinoma (ESCC; n=105). Early tumor stages and well-differentiated tumors showed a significantly higher CYP2C9 expression compared to progressed tumors. Moreover, CYP2C9 expression was correlated to high Ki-67 labeling indices in EAC and Ki-67 positive tumor cells in EAC and ESCC. Selective inhibition of CYP2C9 decreased tumor cell proliferation (KYSE30, PT1590 and OE19) in vitro, which was abolished by 11,12-epoxyeicosatrienoic acid (11,12-EET). Cell-cycle analysis using FACS revealed that inhibition of CYP2C9 leads to a G0/G1 phase cell-cycle arrest. CYP2C9 seems to be relevant for early esophageal cancer development by promoting tumor cell proliferation. Pharmacological inhibition of CYP2C9 might contribute to a more efficient therapy in CYP2C9 highly expressing esophageal cancers.     

Poleward range expansion without a southern contraction in the ground beetle Agonum viridicupreum (Coleoptera, Carabidae)

We investigated the extent of poleward shifts in the distribution range of Agonum viridicupreum due to climate change in the western Palaearctic. Species' records were obtained from extensive literature sources as well as from collections, and consistent amateur entomologists' recordings. Within the general geographic range of the species, we analyzed in detail two parts of both, the northern and southern distribution range boundaries: (1 and 2) north-western Germany (leading or high-latitude edge), (3) Israel and (4) southern Italy (rear or low-latitude edge). Temporal changes in the occurrence data of the species indicated a northward shift of the leading edge of a minimum of 100 km within the last 50 to 100 years. In contrast, according to the data gathered, the rear edge has not changed during the last decades. Further studies are needed in order to fully understand the underlying mechanisms of the different behaviour of leading and rear range edges of Agonum viridicupreum in the current context of global change. Despite our incomplete understanding, chronosequences of the occurrence of the given species have the potential to optimize climate niche modelling to predict trends in the distribution range in the future.     

When to sample in an inaccessible landscape: a case study with carabids from the Allgäu (northern Alps) (Coleoptera, Carabidae)

While pitfall trapping is generally accepted as the standard method for sampling carabid beetles, this method has rarely been used in mountain ecosystems, mainly due to the high labour intensity it involves. As part of a research project in the German Alps, we investigated the phenologic appearance of adult carabid beetles in mountain ecosystems along with the consequences of possible reductions in sampling periods. Our results show that an early activity peak among carabids is predominant in mountain ecosystems. However, there are differences among species: the main group of species showed the highest activity directly after snow melt, a second group showed a delayed activity peak and a small third group had no clear peak at all. Based on this study, we recommend two fortnightly sampling periods as a minimum for a sampling programme: one immediately after snow melt, and a second sampling period after a pause of two weeks.     

Intentional modulation of the late positive potential in response to smoking cues by cognitive strategies in smokers

Attentional bias is considered an important concept in addiction since it has been found to correlate with subjective craving and is strongly associated with relapse after periods of abstinence. Hence, investigating in ways to regulate attention for drug cues would be of major clinical relevance. The present study examined deliberate, cognitive modulation of motivated attention for smoking cues in smokers. The effects of three different reappraisal strategies on an electrophysiological measure of attentive processing were investigated. Early and late LPP components in response to passively viewed neutral and smoking pictures were compared with LPPs in response to smoking pictures that were reappraised with three different reappraisal strategies. Results show that when smokers actively imagine how pleasant it would be to smoke (pleasant condition), their early LPP in response to smoking cues increases, but when smokers actively focus on an alternative stimulus (distraction condition) or think of a rational, uninvolved interpretation of the situation (rational condition), smoking-related late LPP amplitude decreases to the processing level of neutral stimuli. Present results are the first to indicate that smoking cue-elicited LPP amplitudes can be modulated by cognitive strategies, suggesting that attentive processing of smoking cues can be intentionally regulated by smokers with various levels of dependence. Although cognitive strategies can lead to enhanced processing of smoking cues, it is not completely clear whether cognitive strategies are also successful in reducing smoking-related motivated attention. Although findings do point in this direction, present study is best considered preliminary and a starting point for other research on this topic. A focus on the distraction strategy is proposed, as there are indications that this strategy is more successful than the rational strategy in decreasing LPP amplitude.