What Does a Pigeon (Columba livia) Brain Look Like During Homing? Selective Examination of ZENK Expression.

Lesion studies have shown that the avian hippocampus plays a crucial role in homing pigeon (Columba livia) navigation. Using the expression of the immediate early gene protein ZENK in intact pigeons, the authors found regional variation in hippocampal activation as a consequence of homing and, necessarily, the behavior and internal states that accompany it. Specifically, pigeons that homed displayed a significant increase in the number of ZENK-labeled cells in the lateral hippocampal formation compared with pigeons that did not home, whereas no difference was seen in the medial hippocampus. Significant changes in ZENK expression were also found in the medial striatum, which resembles the mammalian ventral striatum. The results identify portions of the hippocampal formation and the medial striatum as sites of plasticity associated with homing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The JDTDOA algorithm applied to signal recovery: a performance analysis

This article suggests a novel method to retrieve a narrowband signal sent in a multipath environment with a delay spread considering ISI between symbols. The proposed method does not require any preamble nor known signal. Using the joint direction and time delay of arrivals estimation algorithm developed in prior work, the directions and time delays of arrival in the multipath channel are jointly estimated and associated while keeping a low computational cost. In this process, a MVDR beamformed copy of each arriving signal is created. The quality of these “pseudo copies” is evaluated and compared to the original direct and reflected signals in this work. Another beamforming method, the Moore–Penrose pseudoinverse, with better retrieval of the direct and reflected signals is also proposed. Using a simple delay-and-sum operation on the previously beamformed copies, it is possible to substantially improve the the system’s performance in terms of bit error rate. An approach using oversampling on the array antenna is introduced to improve performance. Numerical simulations are discussed to support theory.     

Temperature dependence of the characteristic travel distance

The effect of temperature variation on the environmental fate of organic chemicals can be evaluated in steady-state multimedia box models by expressing chemical partitioning data and reaction rate coefficients as functions of temperature. Using such a modelthetemperature dependence of the characteristic travel distance in air L(A), which is a measure for the atmospheric long-range transport potential of organic chemicals, is calculated. Simulations are reported for a set of 40 chemicals of environmental interest. Increasing temperature is shown to have two opposing effects on L(A). Rates of chemical transformations in the atmosphere (k(air)) and surface media are increased, which reduces L(A). Rates of atmospheric deposition (k(dep)) are reduced leading to increased mobility and L(A). Accordingly, L(A) can monotonically increase or decrease with increasing temperature, or it can have a maximum in the modeled temperature range, but it cannot have a minimum. For chemicals with a strong temperature dependence of k(air) relative to k(dep), L(A) will increase with increasing temperature. Results for selected polychlorinated biphenyls are compared to monitoring data yielding qualitative agreement when chemical properties are adjusted to mean temperatures for the measurement period. The results demonstrate that the temperature dependence of the characteristic travel distance is highly dependent on chemical characteristics and can be counterintuitive. The use of mass balance models is thus essential. The difference between the L(A) values at 5 degrees C and 30 degrees C can be up to a factor of 6. Accordingly, chemical ranking with respect to L(A) can change significantly if performed at different temperatures. Implications of the different temperature dependencies on long-range transport to polar regions are discussed.     

Freeze-Dried Fennel Oleoresin Products Formed by Biopolymers: Storage Stability and Characterization

In this work, fennel oleoresin (FO) was encapsulated through freeze drying of the so produced emulsions within different edible biopolymeric carriers. Specifically, modified starch, maltodextrin, chitosan, and gum arabic were used as carriers both individually and in blends (binary and ternary ones). The freeze-dried FO products were characterized in terms of structure (X-ray diffraction (XRD) analysis), whereas their stability was studied by means of sorption isotherm analysis under various a _w. Moreover, the formation of complexes was evaluated through Fourier transform infrared spectroscopy (FTIR) technique and ζ-potential analysis. The verification of the encapsulation process was also conducted by applying FTIR technique. Results showed that the final products presented an amorphous character, whereas the sorption isotherms could be described adequately by the Guggenheim-Anderson-de Boer (GAB) model. FTIR technique proved to be effective to confirm both the formation of complexes and the presence of FO into the studied carriers, verifying thus the success of the process.     

Detection and Quantification of Free Glycerol in Virgin Olive Oil by <Superscript>31</Superscript>P-NMR Spectroscopy

³¹P-Nuclear magnetic resonance (NMR) spectroscopy was employed to detect and quantify free glycerol in virgin olive oils originating from various regions of Greece. This analytical method was based on the derivatization of the hydroxyl groups of glycerol with the tagging reagent 2-chloro-4,4,5,5-tetramethyldioxaphospholane, and identification of the phosphitylated compound on the basis of ³¹P chemical shifts. Quantification of glycerol in olive oils was accomplished by integration of the appropriate signals in the ³¹P NMR spectrum and the use of the phosphitylated cyclohexanol as internal standard. A linear correlation was observed between the glycerol content and 1,3-diacylglycerols and free acidity indicating that glycerol is the final product of the partial hydrolysis of triacylglycerols.     

Passive and active air samplers as complementary methods for investigating persistent organic pollutants in the Great Lakes Basin

Data obtained using passive air samplers (PAS) are compared to active high-volume air sampling data in order to assess the feasibility of the PAS as a method, complementary to active high-volume air sampling (AAS), for monitoring levels of organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) in the Laurentian Great Lakes. PAS were deployed at 15 of the Integrated Atmospheric Deposition Network (IADN) sites on a quarterly basis between July 2002 and June 2003, and PAS and AAS results are compared. Levels for the OC pesticides are typically highest in agricultural areas, with endosulfan I dominating air concentrations with values ranging between 40 and 1090 pg x m(-3), dieldrin values between 15 and 165 pg x m(-3), and gamma-HCH values between 13 and 100 pg x m(-3). alpha-HCH was seen to be relatively uniform across the Great Lakes Basin with values ranging between 15 and 73 pg x m(-3). Large urban centers, such as Chicago and Toronto, have the highest levels of PCBs and PBDEs that range between 400 and 1200 pg x m(-3) and 10 and 70 pg x m(-3), respectively. Comparison of the AAS and the PAS data collected during this study shows good agreement, within a factor of 2 or 3, suggesting that the two sample methods produce comparable results. It is suggested that PAS networks, while providing data that are different in nature from AAS, can provide a cost-effective and complementary approach for monitoring the spatial and temporal trends of persistent organic pollutants.     

Open-lung biopsy in patients with acute respiratory distress syndrome

Occupational exposures contribute to the morbidity and mortality of many diseases. However, occupational diseases continue to be underrecognized even though they are responsible for an estimated 860,000 illnesses and 60,300 deaths each year. Family physicians can play an important role in improving the recognition of occupational disease, preventing progressive illness and disability in their own patients, and contributing to the protection of other workers similarly exposed. This role can be maximized if physicians raise their level of suspicion for workplace disease, develop skills in taking occupational histories and establish routine access to occupational health resources.     

Proteins spontaneously released by rat insulinoma (RIN) cells are anchored on cell membrane by a glycosyl-phosphatidyl-inositol link and inhibit increased RIN cell adhesion of lymphocytes from type 1 diabetic patients and non-obese diabetic mice in vitro

Our group previously reported an assay for the study of lymphocyte adhesion to insulin-producing cells in which xenogeneic rat insulinoma (RIN) cells were used as targets. The present study found an increased number of RIN-cytoadherent lymphocytes in 63 patients with Type 1 diabetes compared with 150 control subjects and in 211 NOD mice compared with 104 BALB/c mice (p < 0.001). Proteins concentrated from spontaneous RIN cell culture supernatants inhibited increased RIN-adhesion of NOD splenocytes or lymphocytes from diabetic patients (p < 0.001). In addition, increased RIN binding was dose-dependently abolished by RIN membrane extracts. The fact that RIN binding was inhibited by proteins from both membrane and the culture supernatant from RIN cells suggests that soluble inhibitory proteins were spontaneously released into the supernatant from a hydrophobic membrane-bound form. This tended to be confirmed since inhibition obtained with both preparations involved a 55-75 kDa HPLC protein fraction. The possibility that the membrane form of the inhibitory protein was anchored by a glycosylphosphatidylinositol (GPI) tail was evaluated. When RIN cells were treated with PI-PLC, their ability to bind lymphocytes from diabetic patients or NOD splenocytes decreased (p < 0.001) to control levels. Co-incubation with the 55-75 kDa fraction of proteins cleaved from RIN cells by PI-PLC also lowered the number of RIN-adherent NOD splenocytes to control levels. SDS-PAGE and IEF analyses of the 55-75 kDa inhibitory fraction from RIN cell supernatant revealed a major band with Mr 66 kDa and PI5.4, which may correspond to a protein with similar characteristics noted on 2-D electrophoresis of proteins cleaved from RIN cells by PI-PLC. Specific labelling of GPI moieties with 3H-ethanolamine, 3H-glucosamine, or 14C-glucosamine, as well as conversion of the hydrophobic Triton-X114 solubilised form into a hydrophilic form after PI-PLC treatment, confirmed the presence of a GPI anchor in this approximately 66 kDa RIN protein, which could thus be the molecule inhibiting adhesion in the system. Our data suggest that GPI-proteins from insulin-producing cells may influence the immune system both in their membrane-anchored and soluble forms. When considering the binding model, in which beta cells were tumoral and xenogeneic to diabetic lymphocytes, this potential influence of GPI-proteins suggests possible implications in situations of lymphocyte-beta cell interaction, i.e. anti-beta cell autoimmunity, immune reaction against insulinomas, and reaction against islet xenografts.