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Head Tissues (head + tissue)
Selected AbstractsIdentification and expression of odorant-binding proteins of the malaria-carrying mosquitoes Anopheles gambiae and Anopheles arabiensisARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 3 2005Zheng-Xi Li Abstract Host preference and blood feeding are restricted to female mosquitoes. Olfaction plays a major role in host-seeking behaviour, which is likely to be associated with a subset of mosquito olfactory genes. Proteins involved in olfaction include the odorant receptors (ORs) and the odorant-binding proteins (OBPs). OBPs are thought to function as a carrier within insect antennae for transporting odours to the olfactory receptors. Here we report the annotation of 32 genes encoding putative OBPs in the malaria mosquito Anopheles gambiae and their tissue-specific expression in two mosquito species of the Anopheles complex; a highly anthropophilic species An. gambiae sensu stricto and an opportunistic, but more zoophilic species, An. arabiensis. RT-PCR shows that some of the genes are expressed mainly in head tissue and a subset of these show highest expression in female heads. One of the genes (agCP1588) which has not been identified as an OBP, has a high similarity (40%) to the Drosophila pheromone-binding protein 4 (PBPRP4) and is only expressed in heads of both An. gambiae and An. arabiensis, and at higher levels in female heads. Two genes (agCP3071 and agCP15554) are expressed only in female heads and agC15554 also shows higher expression levels in An. gambiae. The expression profiles of the genes in the two members of the Anopheles complex provides the first step towards further molecular analysis of the mosquito olfactory apparatus. Arch. Insect Biochem. Physiol. 58:175,189, 2005. © 2005 Wiley-Liss, Inc. [source] Impact of pinna compression on the RF absorption in the heads of adult and juvenile cell phone usersBIOELECTROMAGNETICS, Issue 5 2010Andreas Christ Abstract The electromagnetic exposure of cell phone users depends on several parameters. One of the most dominant of these is the distance between the cell phone and the head tissue. The pinna can be regarded as a spacer between the top of the phone and the head tissue. The size of this spacer has not yet been systematically studied. The objective of this article is to investigate the variations of distance as a function of age of the exposed person, and the mechanical force on the pinna and how it affects the peak spatial specific absorption rate (psSAR). The distances were measured for adults and children (6,8 years of age) while applying a well-defined force on the pinna using a custom-developed measurement device. The average distances of the pinnae to the heads and their standard deviations showed no major differences between the two age groups: 10.5,±,2.0,mm for children (6,8 years) and 9.5,±,2.0,mm for adults. The pinnae of our anatomical high-resolution head models of one adult and two children were transformed according to the measurement results. The numerical exposure analysis showed that the reduced distance due to the pinna compression can increase the maximum 10,g psSAR by approximately 2,dB for adults and children, if the exposure maximum is associated with the upper part of the phone. Bioelectromagnetics 31:406,412, 2010. © 2010 Wiley-Liss, Inc. [source] The history of a developmental stage: Metamorphosis in chordatesGENESIS: THE JOURNAL OF GENETICS AND DEVELOPMENT, Issue 11 2008Mathilde Paris Abstract Metamorphosis displays a striking diversity in chordates, a deuterostome phylum that comprises vertebrates, urochordates (tunicates), and cephalochordates (amphioxus). In anuran amphibians, the tadpole loses its tail, develops limbs, and undergoes profound changes at the behavioral, physiological, biochemical, and ecological levels. In ascidian tunicates, the tail is lost and the head tissues are drastically remodeled into the adult animal, whereas in amphioxus, the highly asymmetric larva transforms into a relatively symmetric adult. This wide diversity has led to the proposal that metamorphosis evolved several times independently in the different chordate lineages during evolution. However, the molecular mechanisms involved in metamorphosis are largely unknown outside amphibians and teleost fishes, in which metamorphosis is regulated by the thyroid hormones (TH) T3 and T4 binding to their receptors (thyroid hormone receptors). In this review, we compare metamorphosis in chordates and then propose a unifying definition of the larva-to-adult transition, based on the conservation of the role of THs and some of their derivatives as the main regulators of metamorphosis. According to this definition, all chordates (if not, all deuterostomes) have a homologous metamorphosis stage during their postembryonic development. The intensity and the nature of the morphological remodeling varies extensively among taxa, from drastic remodeling like in some ascidians or amphibians to more subtle events, as in mammals. genesis 46:657,672, 2008. © 2008 Wiley-Liss, Inc. [source] Improved EEG source analysis using low-resolution conductivity estimation in a four-compartment finite element head modelHUMAN BRAIN MAPPING, Issue 9 2009Seok Lew Abstract Bioelectric source analysis in the human brain from scalp electroencephalography (EEG) signals is sensitive to geometry and conductivity properties of the different head tissues. We propose a low-resolution conductivity estimation (LRCE) method using simulated annealing optimization on high-resolution finite element models that individually optimizes a realistically shaped four-layer volume conductor with regard to the brain and skull compartment conductivities. As input data, the method needs T1- and PD-weighted magnetic resonance images for an improved modeling of the skull and the cerebrospinal fluid compartment and evoked potential data with high signal-to-noise ratio (SNR). Our simulation studies showed that for EEG data with realistic SNR, the LRCE method was able to simultaneously reconstruct both the brain and the skull conductivity together with the underlying dipole source and provided an improved source analysis result. We have also demonstrated the feasibility and applicability of the new method to simultaneously estimate brain and skull conductivity and a somatosensory source from measured tactile somatosensory-evoked potentials of a human subject. Our results show the viability of an approach that computes its own conductivity values and thus reduces the dependence on assigning values from the literature and likely produces a more robust estimate of current sources. Using the LRCE method, the individually optimized four-compartment volume conductor model can, in a second step, be used for the analysis of clinical or cognitive data acquired from the same subject. Hum Brain Mapp, 2009. © 2008 Wiley-Liss, Inc. [source] Stabilizing Smoked Salmon (Oncorhynchus gorbuscha) Tissue after Extraction of OilJOURNAL OF FOOD SCIENCE, Issue 3 2010Cindy Bower ABSTRACT:, Alaska salmon oils are rich in n-3 polyunsaturated fatty acids and are highly valued by the food and pharmaceutical industries. However, the tissue that remains after oil extraction does not have an established market. Discarded pink salmon (Oncorhynchus gorbuscha) tissues were preserved using a combination of smoke-processing and acidification with lactic acid bacteria (LAB). All samples were analyzed for moisture, protein, ash, and lipid contents. Bacterial cell counts, pH, and lactic acid concentrations were recorded as a measure of LAB viability. Neither raw nor smoked salmon were free from spoilage during 60 d of storage. Only fermented samples successfully stabilized below pH 4.7, while retaining lactic acid concentrations over 15 g/L during storage. When smoked, fermented salmon head tissues were dried, the pH of the resulting high-protein "cracker" was significantly lower than when crackers were prepared only from the smoked (but not fermented) salmon material. Both cracker varieties retained valuable polyunsaturated fatty acids. This research suggests that salmon-head tissues discarded after oil extraction represent a good source of protein and high-value fatty acids in a shelf-stable form. Practical Application: Alaska salmon oils are rich in n-3 polyunsaturated fatty acids and are highly valued by the food and pharmaceutical industries. However, the tissue that remains after oil extraction does not have an established market. Material produced from salmon tissue discarded after oil extraction may represent a valuable resource for preparing high-protein crackers and other fish-based food products. In addition to providing a unique smoke-flavoring, the smoked, fermented fish material may also impart antioxidant factors thereby extending the shelf life of the product. [source] Small-size wireless wide area network loop chip antenna for clamshell mobile phone with hearing-aid compatibilityMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2009Wei-Yu Li Abstract A loop chip antenna with an FR4 chip base suitable for clamshell mobile phone application to achieve wireless wide area network operation and hearing-aid compatibility (HAC) is presented. The loop chip antenna is formed by a loop strip excited by a capacitively coupled feed, all printed on the surfaces of the FR4 chip base to achieve a small size of 1.35 cm3 only. Two resonant loop paths are provided by the antenna and each loop path can generate its 0.5, and 1.0, resonant modes with good impedance matching. The excited loop resonant modes are formed into two wide operating bands for the antenna to cover GSM850/900 and GSM1800/1900/UMTS operations for both the open (talk) and closed (idle) states of the clamshell mobile phone. Furthermore, the loop antenna also excites small surface currents on the two ground planes of the clamshell mobile phone. In this case, weak near-field EM fields in the vicinity of the mobile phone can be generated. Results show that the strengths of the near-field E-field and H-field fall in the M3 or M4 Category, making the clamshell mobile phone with the proposed antenna to be an HAC communication device. The obtained specific absorption rate values in 1-g and 10-g head tissues also meet the limit of 1.6 and 2.0 W/kg, respectively. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2327,2335, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24665 [source] | |||||||||||||