ICAN (TRPM4) Contributes to the Intrinsic Excitability of Prefrontal Cortex Layer 2/3 Pyramidal Neurons

Pyramidal neurons in the medial prefrontal cortical layer 2/3 are an essential contributor to the cellular basis of working memory; thus, changes in their intrinsic excitability critically affect medial prefrontal cortex (mPFC) functional properties. Transient Receptor Potential Melastatin 4 (TRPM4), a calcium-activated nonselective cation channel (CAN), regulates the membrane potential in a calcium-dependent manner. In this study, we uncovered the role of TRPM4 in regulating the intrinsic excitability plasticity of pyramidal neurons in the mouse mPFC layer of 2/3 using a combination of conventional and nystatin perforated whole-cell recordings. Interestingly, we found that TRPM4 is open at resting membrane potential, and its inhibition increases input resistance and hyperpolarizes membrane potential. After high-frequency stimulation, pyramidal neurons increase a calcium-activated non-selective cation current, increase the action potential firing, and the amplitude of the afterdepolarization, these effects depend on intracellular calcium. Furthermore, pharmacological inhibition or genetic silencing of TRPM4 reduces the firing rate and the afterdepolarization after high frequency stimulation. Together, these results show that TRPM4 plays a significant role in the excitability of mPFC layer 2/3 pyramidal neurons by modulating neuronal excitability in a calcium-dependent manner.     

Producing Place and Declaring Rights Through Thliitsapilthim (Nuu-chah-nulth First Nations’ Ceremonial Curtains)

Thliitsapilthim (designed ceremonial partitions) are textiles used by Nuu-chah-nulth First Nations families to display their crests, which declare rights, responsibilities, and prestige. These large painted murals adorn and transform spaces, from secular to ceremonial, during potlatches and other significant events. This paper combines nearly a decade of ethnographic fieldwork with archival- and museum-based research to argue that thliitsapilthim function as important legal documents for Nuu-chah-nulth peoples and make declarations about rights to territories, natural resources, ceremonial privileges, and family histories.     

Effects of selenium supplementation on chemical composition and aromatic profiles of cow milk and its derived cheese

This study aimed to investigate the effect of dietary selenium supplementation of Friesian cows on chemical-nutritional and volatile fraction of caciocavallo cheese. A sample of 32 Friesian cows, balanced for parity, milk production, and days in milk, were randomly assigned to 2 groups. The control group (CG) was fed with a conventional feeding strategy, while the experimental group (SeG) received a daily selenomethionine supplementation of 0.45 mg/kg in total mixed ration. During the experimental period, milk yield was monitored, and samples of milk and caciocavallo cheese were collected and analyzed to obtain information on chemical-nutritional composition and volatile compounds profile. Dietary Se integration did not induce variations on milk yield or composition but significantly lowered the somatic cell count (SCC). In both milk and cheese, samples from SeG were characterized by a lower concentration of saturated fatty acids (SFA) and increases in linoleic and rumenic acids. The volatile compounds profile of dairy products was also positively affected by dietary Se intake, with an increase in concentration of free fatty acids, esters, and aldehydes. These results suggest that Se plays a positive role in improving bovine mammary gland functionality and the nutraceutical properties of milk and caciocavallo cheese made therefrom. Such findings could contribute to the production of cheeses with interesting organoleptic properties, although further sensorial evaluations should be performed to deeply investigate these changes and confirm consumer acceptability.     

Geography and stage of development affect persistent organic pollutants in stranded and wild-caught harbor seal pups from central California

Persistent organic pollutants have been associated with disease susceptibility and decreased immunity in marine mammals. Concentrations of polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), polybrominated diphenyl ethers (PBDEs), chlordanes (CHLDs), and hexachlorocyclohexane isomers (HCHs) were evaluated in terms of stage of development and likely exposure routes (in utero, suckling, fasting) in the blubber of 202 stranded and wild-caught, primarily young of the year (n = 177), harbor seals (Phoca vitulina) in the central California coast. This is the first report of HCH concentrations in the blubber of California seals. Lipid normalized concentrations ranged from 200 to 330,000 ng/g for sum PCBs, 320-1,500,000 ng/g for sum DDTs, 23-63,000 ng/g for sum PBDEs, 29-29,000 ng/g for sum CHLDs, and 2-780 ng/g for sum HCHs. The highest concentrations were observed in harbor seal pups that suckled in the wild and then lost mass during the post-weaning fast. Among the pups sampled in the wild and those released from rehabilitation, there were no differences in mass, blubber depth, or percent lipid although contaminant concentrations were significantly higher in the pups which nursed in the wild. When geographic differences were evaluated in a subset of newborn animals collected near their birth locations, the ratio of sum DDTs to sum PCBs was significantly greater in samples from an area with agricultural inputs (Monterey), than one with industrial inputs (San Francisco Bay). A principal components analysis distinguished between seals from San Francisco Bay and Monterey Bay based on specific PCB and PBDE congeners and DDT metabolites. These data illustrate the important influence of life stage, nutritional status, and location on blubber contaminant levels, and thus the need to consider these factors when interpreting single sample measurements in marine mammals.     

Nitrate removal, communities of denitrifiers and adverse effects in different carbon substrates for use in denitrification beds

Denitrification beds are containers filled with wood by-products that serve as a carbon and energy source to denitrifiers, which reduce nitrate (NO₃⁻) from point source discharges into non-reactive dinitrogen (N₂) gas. This study investigates a range of alternative carbon sources and determines rates, mechanisms and factors controlling NO₃⁻ removal, denitrifying bacterial community, and the adverse effects of these substrates. Experimental barrels (0.2 m³) filled with either maize cobs, wheat straw, green waste, sawdust, pine woodchips or eucalyptus woodchips were incubated at 16.8 °C or 27.1 °C (outlet temperature), and received NO₃⁻ enriched water (14.38 mg N L⁻¹ and 17.15 mg N L⁻¹). After 2.5 years of incubation measurements were made of NO₃⁻-N removal rates, in vitro denitrification rates (DR), factors limiting denitrification (carbon and nitrate availability, dissolved oxygen, temperature, pH, and concentrations of NO₃⁻, nitrite and ammonia), copy number of nitrite reductase (nirS and nirK) and nitrous oxide reductase (nosZ) genes, and greenhouse gas production (dissolved nitrous oxide (N₂O) and methane), and carbon (TOC) loss. Microbial denitrification was the main mechanism for NO₃⁻-N removal. Nitrate-N removal rates ranged from 1.3 (pine woodchips) to 6.2 g N m⁻³ d⁻¹ (maize cobs), and were predominantly limited by C availability and temperature (Q₁₀ = 1.2) when NO₃⁻-N outlet concentrations remained above 1 mg L⁻¹. The NO₃⁻-N removal rate did not depend directly on substrate type, but on the quantity of microbially available carbon, which differed between carbon sources. The abundance of denitrifying genes (nirS, nirK and nosZ) was similar in replicate barrels under cold incubation, but varied substantially under warm incubation, and between substrates. Warm incubation enhanced growth of nirS containing bacteria and bacteria that lacked the nosZ gene, potentially explaining the greater N₂O emission in warmer environments. Maize cob substrate had the highest NO₃⁻-N removal rate, but adverse effects include TOC release, dissolved N₂O release and substantial carbon consumption by non-denitrifiers. Woodchips removed less than half of NO₃⁻ removed by maize cobs, but provided ideal conditions for denitrifying bacteria, and adverse effects were not observed. Therefore we recommend the combination of maize cobs and woodchips to enhance NO₃⁻ removal while minimizing adverse effects in denitrification beds.     

Effects of the climatic conditions of the southeastern Brazil on degradation the fibers of coir-geotextile: Evaluation of mechanical and structural properties

In tropical countries where rainfall rates are high, and especially in deforested areas in the Atlantic Rainforest and Cerrado in southeastern Brazil, water is the dominant driving force of erosion. The most common method used to restore degraded tropical lands is to plant nursery-raised tree seedlings, but this method is not always practical and a variety of newer reforestation techniques have become available. Biodegradable coir geotextiles combined with native seeds can be used to restore degraded forest areas. The effects of the climatic conditions during a seasonal cycle of rain and drought were evaluated on the structural and mechanical properties of coir geotextile fibers that were treated, or not, with lime. Analyses of the tensile strength of coir fibers showed that after 12 months of exposure untreated fiber had retained 23% and treated fiber 19% of their initial strength. Two principal factors were considered in evaluating the structural properties of the coir fibers after environmental exposure: (i) initial cellulose retention and its stability after lime-treatment; (ii) lignin degradation and/or its loss to the environment. The structural changes seen by thermogravimetry (TGA) and Fourier Transforms in Infrared spectroscopy (FTIR) analyses explained the changes seen in coir mechanical properties. The greater cellulose contents of fiber structures treated with lime explained their greater tensile strength and high Young's modulus measures after the first three months of exposure in local weather conditions. Considering that lime treatment improved coir fiber properties, lime applications are indicated when coir geotextiles are to be used in acidic Brazilian Cerrado soils.     

Organized turbulent structures—Link between experimental data and LES

Methods of eddy structure identification are applied to velocity data of atmospheric surface layer flows modeled in a boundary-layer wind tunnel. The objective is to test their potential to serve as mathematical tools for the validation of eddy-resolving numerical models like large-eddy simulation and for the generation of realistic turbulent inflow conditions. The reconstruction of complex atmospheric flows on the basis of two-point space-time statistics is tested with the proper orthogonal decomposition and linear stochastic estimation that are both applied to spatially well-resolved flow data. The continuous wavelet transform is used to derive joint time-frequency information from single-point velocity time series. Whereas the proper orthogonal decomposition and the continuous wavelet transform show particular strengths in the spatiotemporal characterization of turbulent flows, the stochastic estimation is moreover qualified to generate new flow scenarios from a minimum number of instantaneous data.     

Fluorescent N2,N3-epsilon-adenine nucleoside and nucleotide probes: synthesis, spectroscopic properties, and biochemical evaluation

N1,N(6)-ethenoadenine, epsilon-A, nucleos(t)ides have been previously applied as fluorescent probes in numerous biochemical systems. However, these epsilon-A analogues lack the H-bonding capability of adenine. To improve the fluorescence characteristics while preserving the H-bonding pattern required for molecular recognition, we designed a novel probe: N(2),N3-etheno-adenosine, (N(2),N3-epsilon-A). Here, we describe four novel syntheses of the target epsilon-nucleoside and related analogues. These methods are short, facile, and provide the product regiospecifically. In addition, we report the absorption and emission spectra of N(2),N3-epsilon-A and the dependence of the spectral features on the pH and polarity of the medium. Specifically, maximum emission of N(2),N3-epsilon-A in water is observed at 420 nm (phi=0.03, excitation at 290 nm). The biochemical relevance of the new probe was evaluated with respect to the P2Y(1) receptor and NTPDases 1 and 2. N(2),N3-epsilon-ATP was found to be almost equipotent with ATP at the P2Y(1) receptor and was hydrolyzed by NTPDases 1 and 2 at about 80 % of the rate of ATP. Furthermore, protein binding does not seem to shift the fluorescence of N(2),N3-epsilon-ATP. Based on the fluorescence and full recognition by ATP-binding proteins, we propose N(2),N3-epsilon-ATP and related nucleo(s)tides as unique probes for the investigation of adenine nucleo(s)tide-binding proteins as well as for other biochemical applications.