Relationship between local temperature and heat transfer through the hand and wrist

The heat uptake that resulted from immersing the hand and wrist into a water-filled calorimeter maintained at temperatures between 37-40 degrees C was measured under standard conditions in a group of eight subjects of either sex. The rate of heat transfer (W) increased exponentially with temperature and was a function of hand or body size and age, but not sex. The heat transfer rate normalized to hand mass (W.kg-1) was determined by temperature and age: best-fit mean values (and 95% confidence limits of the population) were 6.0 W.kg-1 (3.2-11.2 W.kg-1) at an immersion temperature of 37 degrees C and 25.4 W.kg-1 (13.7-47.0 W.kg-1) at 40 degrees C. The application of these results to limits on specific energy absorption rate induced in the hands and wrists by radiofrequency dielectric heat sealer welders is discussed.     

Bayesian network model informs on the impact of biotic and abiotic factors on the population characteristics of an endangered plant species

Preservation of the endangered plant species requires knowledge of the impact of environmental factors on their populations. This study was undertaken to evaluate the potential of a Bayesian network (BN) model to analyze the impact of habitat conditions on the current characteristics of Pulsatilla patens (L.) Mill. population in NE Poland. The model was based on field data collected in 2011–2015 from 47 sites in the four largest forest complexes of NE Poland. The causal network between (1) the biotic and (2) abiotic factors as well as morphological-developmental features of individuals and demographic features of populations (20 attributes, 1573 records) was made using the Bayesian Search Algorithm in GeNIe 2.0. The results indicate that the greatest impact on the population features had the number of competing species in forest undergrowth and exposition of slopes. Diagnostic testing and sensitivity analysis revealed that these factors were the major variables determining the size of the population, developmental phase, and the size of individuals. Tenfold cross-validation revealed that this model was the most effective to analyze the impact of habitat conditions on the presence of generative shoots, developmental phase, and juvenile shoots. The optimal levels of factors following from the BN modeling of the impact of habitat conditions on the characteristics of the population will allow regular growth (size of individuals) and development (life cycle of individuals) of a given endangered species.     

Structure and reactivity of Trypanosoma brucei pteridine reductase: inhibition by the archetypal antifolate methotrexate

The protozoan Trypanosoma brucei has a functional pteridine reductase (TbPTR1), an NADPH-dependent short-chain reductase that participates in the salvage of pterins, which are essential for parasite growth. PTR1 displays broad-spectrum activity with pterins and folates, provides a metabolic bypass for inhibition of the trypanosomatid dihydrofolate reductase and therefore compromises the use of antifolates for treatment of trypanosomiasis. Catalytic properties of recombinant TbPTR1 and inhibition by the archetypal antifolate methotrexate have been characterized and the crystal structure of the ternary complex with cofactor NADP+ and the inhibitor determined at 2.2 A resolution. This enzyme shares 50% amino acid sequence identity with Leishmania major PTR1 (LmPTR1) and comparisons show that the architecture of the cofactor binding site, and the catalytic centre are highly conserved, as are most interactions with the inhibitor. However, specific amino acid differences, in particular the placement of Trp221 at the side of the active site, and adjustment of the beta6-alpha6 loop and alpha6 helix at one side of the substrate-binding cleft significantly reduce the size of the substrate binding site of TbPTR1 and alter the chemical properties compared with LmPTR1. A reactive Cys168, within the active site cleft, in conjunction with the C-terminus carboxyl group and His267 of a partner subunit forms a triad similar to the catalytic component of cysteine proteases. TbPTR1 therefore offers novel structural features to exploit in the search for inhibitors of therapeutic value against African trypanosomiasis.     

Evidence of lipid peroxidation and protein phosphorylation in cells upon oxidative stress photo-generated by fullerols

An oxidative stress (OS) state is characterized by the generation of Reactive Oxygen Species (ROS) in a biological system above its capacity to counterbalance them [1]. Exposure to OS induces the accumulation of intracellular ROS, which in turn causes cell damage in the form of protein, lipid, and/or DNA oxidations. Such conditions are believed to be linked to numerous diseases or simply to the ageing of tissues. However, the controlled generation of ROS via photosensitizing drugs or photosensitizers (PS) is now widely used to treat various tumors and other infections [2,3]. Here we present a method to track the chemical changes in a cell after exposure to oxidative stress. OS is induced via fullerols, a custom made water soluble derivative of fullerene (C(60)), under visible light illumination. Synchrotron-based Fourier Transform InfraRed Microspectroscopy (S-FTIRM) was used to assess the chemical makeup of single cells after OS exposure. Consequently, a chemical fingerprint of oxidative stress was probed in this study through an increase in the bands linked with lipid peroxidation (carbonyl ester group at 1740 cm(-1)) and protein phosphorylation (asymmetric phosphate stretching at 1240 cm(-1)).     

Adrenergic, nitrergic and peptidergic innervation of the urethral muscle in the boar

In this study, the innervation of the urethral muscle in adult male pigs was investigated using combined NADPH-diaphorase (NADPH-d) histochemistry and immunocytochemistry. Nerve fibres supplying the urethral muscle were found to show NADPH-d activity and they also expressed immunoreactivity to catecholamine synthesising enzymes including tyrosine hydoxylase (TH) and dopamine-beta-hydroxylase (DbetaH) as well as to: vasoactive intestinal polypeptide (VIP) and neuropeptide Y (NPY). Different subpopulations of the nerve fibres (NADPH-d positive, TH-, DbetaH-, VIP- and NPY-immunoreactive (IR), but also NADPH-d/VIP- and NADPH-d/NPY-IR) were disclosed. These nerve fibres were observed not only to run among muscle fibres of the urethral muscle, but also within extrinsic nerve trunks. Moreover, in the organ studied, numerous ganglia were found. The intramural ganglia, composed of a few to 30 neurons were located in the proximal, middle and distal regions of the pelvic urethra. In the vicinity of the urethral muscle, there were mainly small ganglia containing two to several neurons, but also larger ganglia consisting of up to tens neurons were encountered in the connective tissue surrounding the pelvic urethra. In the ganglia observed in the neighbourhood of the urethral muscle, different subpopulations of nerve cells were found, namely: catecholaminergic, nitrergic, VIP-IR, NPY-IR and also NADPH-d/DbetaH-, NADPH-d/VIP- and NADPH-d/NPY-positive. Possible sources of the innervation for this muscle were also discussed.     

Erotylidae (Insecta, Coleoptera) of Poland - problematic taxa, updated keys and new records

New data concerning the occurrence of pleasing fungus beetles (Coleoptera: Erotylidae) in Poland are given, with a focus on rare and difficult to identify Central European taxa. Cryptophilus cf. integer (Heer) (Cryptophilinae) is reported from the Polish territory for the first time based on adult and larval specimens collected in the Wielkopolska-Kujawy Lowland. Identification problems concerning species of Cryptophilus introduced to Europe are discussed. Triplax carpathica Reitter (Erotylinae) is recorded from the Białowieża Primeval Forest, which is the first known non-Carpathian finding of this species, located in the close proximity of the Polish-Belarussian UNESCO World Heritage Site “Białowieża Forest”. Discussion of Triplax carpathica being conspecific with Siberian Triplax rufiventris Gebler is provided. New Polish localities of several other Erotylidae are reported, and an updated key to Central European species of Triplax is given. The Triplax key is supplemented with dorsal and ventral habitus images of all treated Triplax species. One of the rarest Central European erotyline species Combocerus glaber (Schaller) is recorded from xerothermic grasslands in North-West Poland.     

Cochlin induced TREK-1 co-expression and annexin A2 secretion: role in trabecular meshwork cell elongation and motility

Fluid flow through large interstitial spaces is sensed at the cellular level, and mechanistic responses to flow changes enables expansion or contraction of the cells modulating the surrounding area and brings about changes in fluid flow. In the anterior eye chamber, aqueous humor, a clear fluid, flows through trabecular meshwork (TM), a filter like region. Cochlin, a secreted protein in the extracellular matrix, was identified in the TM of glaucomatous patients but not controls by mass spectrometry. Cochlin undergoes shear induced multimerization and plays a role in mechanosensing of fluid shear. Cytoskeletal changes in response to mechanosensing in the ECM by cochlin will necessitate transduction of mechanosensing. TREK-1, a stretch activated outward rectifying potassium channel protein known to act as mechanotransducer was found to be expressed in TM. Cochlin expression results in co-expression of TREK-1 and filopodia formation. Prolonged cochlin expression results in expression and subsequent secretion of annexin A2, a protein known to play a role in cytoskeletal remodeling. Cochlin interacts with TREK-1 and annexin A2. Cochlin-TREK-1 interaction has functional consequences and results in changes in cell shape and motility. Annexin A2 expression and secretion follows cochlin-TREK-1 syn-expression and correlates with cell elongation. Thus cytoskeleton changes in response to fluid shear sensed by cochlin are further mediated by TREK-1 and annexin A2.     

Collective emotions online and their influence on community life

Background

E-communities, social groups interacting online, have recently become an object of interdisciplinary research. As with face-to-face meetings, Internet exchanges may not only include factual information but also emotional information – how participants feel about the subject discussed or other group members. Emotions in turn are known to be important in affecting interaction partners in offline communication in many ways. Could emotions in Internet exchanges affect others and systematically influence quantitative and qualitative aspects of the trajectory of e-communities? The development of automatic sentiment analysis has made large scale emotion detection and analysis possible using text messages collected from the web. However, it is not clear if emotions in e-communities primarily derive from individual group members'' personalities or if they result from intra-group interactions, and whether they influence group activities.

Methodology/Principal Findings

Here, for the first time, we show the collective character of affective phenomena on a large scale as observed in four million posts downloaded from Blogs, Digg and BBC forums. To test whether the emotions of a community member may influence the emotions of others, posts were grouped into clusters of messages with similar emotional valences. The frequency of long clusters was much higher than it would be if emotions occurred at random. Distributions for cluster lengths can be explained by preferential processes because conditional probabilities for consecutive messages grow as a power law with cluster length. For BBC forum threads, average discussion lengths were higher for larger values of absolute average emotional valence in the first ten comments and the average amount of emotion in messages fell during discussions.

Conclusions/Significance

Overall, our results prove that collective emotional states can be created and modulated via Internet communication and that emotional expressiveness is the fuel that sustains some e-communities.     

Band Shape Analysis of Vibronic Spectra of Flexible Molecules in Solution

Abstract

The absorption and emission spectra of biphenyl in cyclohexane are measured. Calculated Franck-Condon overlap integrals are used to simulate measured absorption and emission spectra of biphenyl in cyclohexane. The vibronic theory with the Born-Oppenheimer and Condon approximation is used.