Ligula intestinalis (Cestoda: Pseudophyllidea): an ideal fish-metazoan parasite model?

Since its use as a model to study metazoan parasite culture and in vitro development, the plerocercoid of the tapeworm, Ligula intestinalis, has served as a useful scientific tool to study a range of biological factors, particularly within its fish intermediate host. From the extensive long-term ecological studies on the interactions between the parasite and cyprinid hosts, to the recent advances made using molecular technology on parasite diversity and speciation, studies on the parasite have, over the last 60 years, led to significant advances in knowledge on host-parasite interactions. The parasite has served as a useful model to study pollution, immunology and parasite ecology and genetics, as well has being the archetypal endocrine disruptor

Do airstream mechanisms influence tongue movement paths?

Velar consonants often show an elliptical pattern of tongue movement in symmetrical vowel contexts, but the forces responsible for this remain unclear. We here consider the role of overpressure (increased intraoral air pressure) behind the constriction by examining how movement patterns are modified when speakers change from an egressive to ingressive airstream. Tongue movement and respiratory data were obtained from 3 speakers. The two airstream conditions were additionally combined with two levels of speech volume. The results showed consistent reductions in forward tongue movement during consonant closure in the ingressive conditions. Thus, overpressure behind the constriction may partly determine preferred movement patterns, but it cannot be the only influence since forward movement during closure is usually reduced but not eliminated in ingressive speech

Covariation Among Vowel Height Effects on Acoustic Measures

Covariation among vowel height effects on vowel intrinsic fundamental frequency (IF0), voice onset time (VOT), and voiceless interval duration (VID) is analyzed to assess the plausibility of a common physiological mechanism underlying variation in these measures. Phrases spoken by 20 young adults, containing words composed of initial voiceless stops or /s/ and high or low vowels, were produced in habitual and voluntarily increased F0 conditions. High vowels were associated with increased IF0 and longer VIDs. VOT and VID exhibited significant covariation with IF0 only for males at habitua

Glucagon-like peptide-1 protects against ischemic left ventricular dysfunction during hyperglycemia in patients with coronary artery disease and type 2 diabetes mellitus.

BACKGROUND: Enhancement of myocardial glucose uptake may reduce fatty acid oxidation and improve tolerance to ischemia. Hyperglycemia, in association with hyperinsulinemia, stimulates this metabolic change but may have deleterious effects on left ventricular (LV) function. The incretin hormone, glucagon-like peptide-1 (GLP-1), also has favorable cardiovascular effects, and has emerged as an alternative method of altering myocardial substrate utilization. In patients with coronary artery disease (CAD), we investigated: (1) the effect of a hyperinsulinemic hyperglycemic clamp (HHC) on myocardial performance during dobutamine stress echocardiography (DSE), and (2) whether an infusion of GLP-1(7-36) at the time of HHC protects against ischemic LV dysfunction during DSE in patients with type 2 diabetes mellitus (T2DM). METHODS: In study 1, twelve patients underwent two DSEs with tissue Doppler imaging (TDI)-one during the steady-state phase of a HHC. In study 2, ten patients with T2DM underwent two DSEs with TDI during the steady-state phase of a HHC. GLP-1(7-36) was infused intravenously at 1.2 pmol/kg/min during one of the scans. In both studies, global LV function was assessed by ejection fraction and mitral annular systolic velocity, and regional wall LV function was assessed using peak systolic velocity, strain and strain rate from 12 paired non-apical segments. RESULTS: In study 1, the HHC (compared with control) increased glucose (13.0 ± 1.9 versus 4.8 ± 0.5 mmol/l, p < 0.0001) and insulin (1,212 ± 514 versus 114 ± 47 pmol/l, p = 0.01) concentrations, and reduced FFA levels (249 ± 175 versus 1,001 ± 333 μmol/l, p < 0.0001), but had no net effect on either global or regional LV function. In study 2, GLP-1 enhanced both global (ejection fraction, 77.5 ± 5.0 versus 71.3 ± 4.3%, p = 0.004) and regional (peak systolic strain -18.1 ± 6.6 versus -15.5 ± 5.4%, p < 0.0001) myocardial performance at peak stress and at 30 min recovery. These effects were predominantly driven by a reduction in contractile dysfunction in regions subject to demand ischemia. CONCLUSIONS: In patients with CAD, hyperinsulinemic hyperglycemia has a neutral effect on LV function during DSE. However, GLP-1 at the time of hyperglycemia improves myocardial tolerance to demand ischemia in patients with T2DM. TRIAL REGISTRATION: http://www.isrctn.org . Unique identifier ISRCTN69686930

Pathological and ecological host consequences of infection by an introduced fish parasite

The infection consequences of the introduced cestode fish parasite Bothriocephalus acheilognathi were studied in a cohort of wild, young-of-the-year common carp Cyprinus carpio that lacked co-evolution with the parasite. Within the cohort, parasite prevalence was 42% and parasite burdens were up to 12% body weight. Pathological changes within the intestinal tract of parasitized carp included distension of the gut wall, epithelial compression and degeneration, pressure necrosis and varied inflammatory changes. These were most pronounced in regions containing the largest proportion of mature proglottids. Although the body lengths of parasitized and non-parasitized fish were not significantly different, parasitized fish were of lower body condition and reduced weight compared to non-parasitized conspecifics. Stable isotope analysis (δ15N and δ13C) revealed trophic impacts associated with infection, particularly for δ15N where values for parasitized fish were significantly reduced as their parasite burden increased. In a controlled aquarium environment where the fish were fed ad libitum on an identical food source, there was no significant difference in values of δ15N and δ13C between parasitized and non-parasitized fish. The growth consequences remained, however, with parasitized fish growing significantly slower than non-parasitized fish, with their feeding rate (items s−1) also significantly lower. Thus, infection by an introduced parasite had multiple pathological, ecological and trophic impacts on a host with no experience of the parasite

Distribution, magnitudes, reactivities, ratios and diurnal patterns of volatile organic compounds in the Valley of Mexico during the MCMA 2002 and 2003 field campaigns

International audienceA wide array of volatile organic compound (VOC) measurements was conducted in the Valley of Mexico during the MCMA-2002 and 2003 field campaigns. Study sites included locations in the urban core, in a heavily industrial area and at boundary sites in rural landscapes. In addition, a novel mobile-laboratory-based conditional sampling method was used to collect samples dominated by fresh on-road vehicle exhaust to identify those VOCs whose ambient concentrations were primarily due to vehicle emissions. Five distinct analytical techniques were used: whole air canister samples with Gas Chromatography/Flame Ionization Detection (GC-FID), on-line chemical ionization using a Proton Transfer Reaction Mass Spectrometer (PTR-MS), continuous real-time detection of olefins using a Fast Olefin Sensor (FOS), and long path measurements using UV Differential Optical Absorption Spectrometers (DOAS). The simultaneous use of these techniques provided a wide range of individual VOC measurements with different spatial and temporal scales. The VOC data were analyzed to understand concentration and spatial distributions, diurnal patterns, origin and reactivity in the atmosphere of Mexico City. The VOC burden (in ppbC) was dominated by alkanes (60%), followed by aromatics (15%) and olefins (5%). The remaining 20% was a mix of alkynes, halogenated hydrocarbons, oxygenated species (esters, ethers, etc.) and other unidentified VOCs. However, in terms of ozone production, olefins were the most relevant hydrocarbons. Elevated levels of toxic hydrocarbons, such as 1,3-butadiene, benzene, toluene and xylenes were also observed. Results from these various analytical techniques showed that vehicle exhaust is the main source of VOCs in Mexico City and that diurnal patterns depend on vehicular traffic. Finally, examination of the VOC data in terms of lumped modeling VOC classes and its comparison to the VOC lumped emissions reported in other photochemical air quality modeling studies suggests that some, but not all, VOC classes are underestimated in the emissions inventory by factors of 1.1 to 3

Structure in mind, structure in vocal tract

We update our understanding of the view that grammar regulates intersegmental temporal coordination and present an extension of that view to a new domain: we argue that inter-segmental coordination is basic to prosody. It is the glue joining segments together differently in different languages (here, illustrated with examples from Arabic and Spanish) and orchestrates their unfolding in ways corresponding to constructs posited in theoretical analysis. The correspondence is one between organization in mind-brain and organization in vocal tract. Moreover, for both mind-brain and vocal tract, the organization is phonological and abstract. It is so because it holds over segments of various identities: in Arabic, the first segment in /bka/ is not prosodified as part of the same unit as /ka/ and this holds true also for /blat/, /klat/ and so on, regardless of sonority. In contrast, in English or Spanish, a different organization holds. Crucially, uniformity in organization (same organization presiding over sequences with varying segmental makeup) does not imply uniqueness of phonetic exponents: prosodic organization is pleiotropic, simultaneously expressed by more than one phonetic exponent. Finally, two properties of coordination relations are underscored: lawful flexibility and abstractness. The first is revealed in the degrees of freedom with which movements corresponding to any given effector begin; the second in invariances of task-relevant kinematic signatures regardless of the effectors implicated in any given segmental sequence. Once again, abstract phonological structure is mirrored in vocal tracts via coordination relations holding across physiology and the particular modes of its operation

Linear Smart Array Antenna Configurations for a Transceiver in a Multi-Signal Environment

Future smart antenna technology requires multielement, adaptive array antennas to be placed on very small cell phone units. Small adaptive array antennas require heavy signal processing if the statistical techniques are used to maximize radiation in the desired direction and to null the beam in the direction of interfering signals. In terms of weight, battery energy and computational memory and time required it is imperative to minimize computational time, memory required and weight of the hardware to be used for adaptive beamforming in smart antennas. In this paper is presented a three-element antenna that uses analytically solved weight computation. No statistical or number crunching techniques are used. Moreover, it is shown that the antenna elements behind which two signal processing units are placed are critical. The placement of the weight processing signal processing units is critical for obtaining simultaneous beam maximizing towards the desired direction and nulling towards the interferer direction

Ground to Cloud Lightning Flash Currents and Electric Fields: Interaction with Aircraft and Production of Ionosphere Sprites

This paper presents for the first time a case for the importance of ground to cloud (upward leader) lightning flash parameters for safety testing of direct aircraft-lightning interaction and protection of wind turbines, as well as the importance of radiated electric fields for indirect lightning-aircraft interaction and generation of electric discharges called sprites and halos in the ionosphere. By using an electric circuit model of the transverse magnetic waves along the return stroke channel, electric currents at ground level as well as cloud level are determined for both the cloud to ground lightning flash and the ground to cloud lightning flash. We show that when an aircraft triggers lightning, the electric currents will be much more severe in current magnitude, rate of rise of currents, and frequency spectrum than otherwise and are more severe than the parameters observed for the usual and well monitored (and measured) cloud to ground (downward leader) flashes. The rate of rise of currents and the frequency spectrum of the ground to cloud lightning flash are also given here. The electric fields radiated by the lightning flashes that would appear in the ionosphere are presented for both the earth flash and the ground to cloud flash.</jats:p

The university as a just anchor: universities, anchor networks and participatory research

In this paper, we connect literature on civic universities and anchor institutions with the notion of visibility to explore how universities can play more engaged roles in their areas. We introduce the concept of ‘just anchors’, which are institutions with strategies to achieve local social, economic and epistemic justice goals through collaboration in networks of other anchors and knowledge co-production with citizens. This paper is based on data from USE-IT!, an ERDF-funded programme that developed mechanisms to build social resilience in inner-city wards of Birmingham, the second-largest city in England. Our findings show that co-production empowers citizens, and that universities are well-placed to facilitate and benefit from the outputs of this process. Based on the experience of delivering a community researcher training scheme, we reflect on the potential of universities to be more visible to, and facilitate the visibility of, marginalised groups, introducing a new theoretical concept into the literature on universities as anchor institutions. We also draw further lessons from USE-IT! to offer practice-based recommendations to other universities seeking to activate their role as just anchors