Effects of herbicides on Selenastrum capricornutum and Daphnia magna

The toxicity of five herbicides, Propanil, Machete, Rilof-H, Saturn, and Ronestar, commonly used in Iranian rice fields, were investigated in acute toxicity bioassays on two organisms belonging to different in aquatic food chain. Compared with Daphnia magna, green algae Selenastrum capricornutum, showed more sensitivly to the herbicides. Machete and Saturn were the most toxic herbicides for algae. Three other herbicides, having more effect on the toxicity rate were Ronestar, Rilof-H, and Propanil. The toxic herbicides for Daphnia magna were Rilof-H and Saturn, and the others showed less toxicity. Comparing the amount of 6 to 23 mg/1 field concentrations of the herbicides with 0.01 to 12.46 mg/1 MAV-values for Selenastrum capticomutum and 0.446 to 9.5 mg/1, MAC-values for Daphnia magna in laboratory experiments revealed that the herbicides would certainly kill all useful organisms in aquatic food chain such as algae and zooplanktons in rice fields, and would damage other neighboring ecosystems in rivers, reservoirs, lagoon and the Caspian Sea which are connected with the fields. Ministry of Agriculture should be asked to introduce other less toxic herbicides

Effects of diazinon, malathion, machete and saturn on mortality of fingerling of Rutilus frisii kutum

The toxicity of the pesticides, malathion and diazinon, and the herbicides, Machete and Saturn, on mortality of fingerling of Rutilus frisii kutum were examined. Lc10 values for diazinon, Malathion, Machete and Saturn were 0.14 - 0.24, 0.10 - 0.35, 0.14 - 0.55, and 1.45 - 2.50 mg/L respectively. The result showed that diazinon, malathion and machete have a highly toxic effect on fingerling of R. frisii kutum and the herbicide, saturn, in comparison with other poisons was less toxic

NASCENT: an automatic protein interaction network generation tool for non-model organisms.

Large quantity of reliable protein interaction data are available for model organisms in public depositories (e.g., MINT, DIP, HPRD, INTERACT). Most data correspond to experiments with the proteins of Saccharomyces cerevisiae, Drosophila melanogaster, Homo sapiens, Caenorhabditis elegans, Escherichia coli and Mus musculus. For other important organisms the data availability is poor or non-existent. Here we present NASCENT, a completely automatic web-based tool and also a downloadable Java program, capable of modeling and generating protein interaction networks even for non-model organisms. The tool performs protein interaction network modeling through gene-name mapping, and outputs the resulting network in graphical form and also in computer-readable graph-forms, directly applicable by popular network modeling software. AVAILABILITY: http://nascent.pitgroup.org

Ecotoxicological studies on Daphnia magna

In this study we used Daphnia magna as an index organism for ecotoxicological studies. In order to determine the filtration and ingestion rates in Daphnia magna, we used algea Chlorella volgaris (10 mg/1). Prior to the tests, the acute toxicity of the herbicides Machete and Saturn and the pesticides Diazinon and Malathion, in order to calculate their EC50, were determined. The concentrations which caused the same mortality rate in 24 hours as the EC50 concentrations of these chemical did, were 18.49 mg/1 for Machete, 4.46mg/1 for Saturn, 0.31 gr/1 for Diazinon and 1.5 grit for Malathion. In order to study the toxic effect of Machete, Saturn, Diazinon and Malathion on the filtration and ingestion rates, Daphnia magna was exposed to Ec50, 3/4 Ec50 ,1/2 Ec50 and 1/4 Ec50 concentrations. The rates were reduced after the organism had been exposed to these toxic chemicals for 5 hours. The effective concentrations at which feeding rate were reduced by 50%, compared to the controls, were for herbicides activity and pesticides action. These values in regard to filtration and ingestion rates were 2.8 and 3.3 mg/1 for Machete, 1.45 and 1.6 mg/1 for Saturn, 0.16 and 0.075 mg/1 for Diazinon and 0.6 and 0.7 mg/1 for Malathion respectively

Correlation Between Freezing Sites and Xylem Vessel Diameter for Three Chaparral Species of the Santa Monica Mountains

Coastal exposures of the Santa Monica Mountains rarely experience freezing temperatures (0 °C) because of the ameliorating effects of the Pacific Ocean and seawater’s specific heat capacity. In contrast, inland sites of the Santa Monica Mountains frequently experience winter temperatures below -10 °C. This temperature gradient, from coast to inland, may be a major determinate of species distribution patterns. To investigate possible mechanisms by which freezing impacts chaparral distribution patterns, we examined xylem vessel diameter and vessel length of three chaparral species growing at inland freezing sites versus coastal nonfreezing sites (Malosma laurina, Umbellularia californica, and Ceanothus megacarpus). It has been established that vessel size influences freezing-induced embolism and the blockage of xylem water transport from soil to leaves. However, it is not known if this “size effect” is primarily due to vessel diameter, vessel length, or both. We initially hypothesized that matched species-pairs at non-freezing sites would have both longer and wider vessels than at freezing sites. We determined maximum vessel length by injecting air into stems at decreasing segment lengths and mean vessel diameters by using an ocular micrometer in conjunction with a light microscope. Sample sizes were six for each species pairs. For all three species, mean vessel diameters were narrower at freezing than non-freezing sites (P \u3c 0.05) ranging between 13 µm mean differences for C. megacarpus to 20.4 µm mean differences for U. californica. In contrast, we found no significant difference in vessel lengths for any of the species-pairs (P \u3e 0.05). We conclude that reduction in vessel diameter is more significant than reduction in vessel length for protection from freezing-induced embolism of stem xylem. Furthermore, limits in the genetic plasticity of some species to reduce vessel diameter may preclude their survival at freezing sites

The Effect of Freezing Conditions on Xylem Diameter of Malosma laurina and Umbellularia californica in the Santa Monica Mountains

Temperature variations in the Santa Monica Mountains are drastic at times, which may be affecting the local plants. To determine the repercussions of these variations in temperature, we measured the xylem diameters of freezing and non-freezing Malosma laurina and Umbellularia californica. U. californica was chosen because it has a large xylem diameter, yet is known to survive freezing conditions. We thought that this plant could provide the most significant results to prove or disprove our hypothesis. M. laurina was chosen because it is abundant in the Santa Monica Mountains and has different physical dimensions than U. californica. Smaller xylem diameters may affect water transport , possibly resulting in physically smaller plant sizes. Natural selection may be acting on these species in the Santa Monica Mountains, eliminating plants with larger xylem diameters in freezing areas. We hypothesize that M. laurina and U. californica in freezing zones will have smaller xylem diameters compared to those in non-freezing zones. We collected samples of M. laurina and U. californica from freezing and non-freezing sites located in Tapia Park and Solstice park in the Santa Monica Mountains and on Pepperdine University’s Malibu Campus. We then prepared slides of the plants’ stems and measured the diameters of the xylems. Using Kaleidagraph, we statistically analyzed our data and found the average values for each plant; freezing M. laurina had an average xylem diameter of 33.3 μm, non-freezing M. laurina had an average xylem diameter of 48.7 μm, freezing U. californica had an average xylem diameter of 33.4 μm, and non-freezing U. californica had an average xylem diameter of 53.8 μm. These results indicate significance as revealed by a p value \u3c0.05

Structure in the Magnetic Field of the Milky Way Disk and Halo traced by Faraday Rotation

Magnetic fields in the ionized medium of the disk and halo of the Milky Way impose Faraday rotation on linearly polarized radio emission. We compare two surveys mapping the Galactic Faraday rotation, one showing the rotation measures of extragalactic sources seen through the Galaxy (from Hutschenreuter et al 2022), and one showing the Faraday depth of the diffuse Galactic synchrotron emission from the Global Magneto-Ionic Medium Survey. Comparing the two data sets in 5deg x 10deg bins shows good agreement at intermediate latitudes, 10 < |b| < 50 deg, and little correlation between them at lower and higher latitudes. Where they agree, both tracers show clear patterns as a function of Galactic longitude: in the Northern Hemisphere a strong sin(2 x longitude) pattern, and in the Southern hemisphere a sin(longitude + pi) pattern. Pulsars with height above or below the plane |z| > 300 pc show similar longitude dependence in their rotation measures. Nearby non-thermal structures show rotation measure shadows as does the Orion-Eridanus superbubble. We describe families of dynamo models that could explain the observed patterns in the two hemispheres. We suggest that a field reversal, known to cross the plane a few hundred pc inside the solar circle, could shift to positive z with increasing Galactic radius to explain the sin(2xlongitude) pattern in the Northern Hemisphere. Correlation shows that rotation measures from extragalactic sources are one to two times the corresponding rotation measure of the diffuse emission, implying Faraday complexity along some lines of sight, especially in the Southern hemisphere.Comment: 37 pages, 26 figures, Ap. J. accepte

Light transmittance in human atrial tissue and transthoracic illumination in rats support translatability of optogenetic cardioversion of atrial fibrillation

Background: Optogenetics could offer a solution to the current lack of an ambulatory method for the rapid automated cardioversion of atrial fibrillation (AF), but key translational aspects remain to be studied. Objective: To investigate whether optogenetic cardioversion of AF is effective in the aged heart and whether sufficient light penetrates the human atrial wall. Methods: Atria of adult and aged rats were optogenetically modified to express light-gated ion channels (i.e., red-activatable channelrhodopsin), followed by AF induction and atrial illumination to determine the effectivity of optogenetic cardioversion. The irradiance level was determined by light transmittance measurements on human atrial tissue. Results: AF could be effectively terminated in the remodeled atria of aged rats (97%, n = 6). Subsequently, ex vivo experiments using human atrial auricles demonstrated that 565-nm light pulses at an intensity of 25 mW/mm(2) achieved the complete penetration of the atrial wall. Applying such irradiation onto the chest of adult rats resulted in transthoracic atrial illumination as evidenced by the optogenetic cardioversion of AF (90%, n = 4). Conclusion: Transthoracic optogenetic cardioversion of AF is effective in the aged rat heart using irradiation levels compatible with human atrial transmural light penetration.Thoracic Surger

A Detection of Cosmological 21 cm Emission from CHIME in Cross-correlation with eBOSS Measurements of the Lyman-α\alpha Forest

We report the detection of 21 cm emission at an average redshift $\bar{z} = 2.3$ in the cross-correlation of data from the Canadian Hydrogen Intensity Mapping Experiment (CHIME) with measurements of the Lyman-$\alpha$ forest from eBOSS. Data collected by CHIME over 88 days in the $400-500$~MHz frequency band ($1.8 < z < 2.5$) are formed into maps of the sky and high-pass delay filtered to suppress the foreground power, corresponding to removing cosmological scales with $k_\parallel \lesssim 0.13\ \text{Mpc}^{-1}$ at the average redshift. Line-of-sight spectra to the eBOSS background quasar locations are extracted from the CHIME maps and combined with the Lyman-$\alpha$ forest flux transmission spectra to estimate the 21 cm-Lyman-$\alpha$ cross-correlation function. Fitting a simulation-derived template function to this measurement results in a $9\sigma$ detection significance. The coherent accumulation of the signal through cross-correlation is sufficient to enable a detection despite excess variance from foreground residuals $\sim6-10$ times brighter than the expected thermal noise level in the correlation function. These results are the highest-redshift measurement of \tcm emission to date, and set the stage for future 21 cm intensity mapping analyses at $z>1.8$

Changes in the gastric enteric nervous system and muscle: A case report on two patients with diabetic gastroparesis

<p>Abstract</p> <p>Background</p> <p>The pathophysiological basis of diabetic gastroparesis is poorly understood, in large part due to the almost complete lack of data on neuropathological and molecular changes in the stomachs of patients. Experimental models indicate various lesions affecting the vagus, muscle, enteric neurons, interstitial cells of Cajal (ICC) or other cellular components. The aim of this study was to use modern analytical methods to determine morphological and molecular changes in the gastric wall in patients with diabetic gastroparesis.</p> <p>Methods</p> <p>Full thickness gastric biopsies were obtained laparoscopically from two gastroparetic patients undergoing surgical intervention and from disease-free areas of control subjects undergoing other forms of gastric surgery. Samples were processed for histological and immunohistochemical examination.</p> <p>Results</p> <p>Although both patients had severe refractory symptoms with malnutrition, requiring the placement of a gastric stimulator, one of them had no significant abnormalities as compared with controls. This patient had an abrupt onset of symptoms with a relatively short duration of diabetes that was well controlled. By contrast, the other patient had long standing brittle and poorly controlled diabetes with numerous episodes of diabetic ketoacidosis and frequent hypoglycemic episodes. Histological examination in this patient revealed increased fibrosis in the muscle layers as well as significantly fewer nerve fibers and myenteric neurons as assessed by PGP9.5 staining. Further, significant reduction was seen in staining for neuronal nitric oxide synthase, heme oxygenase-2, tyrosine hydroxylase as well as for c-KIT.</p> <p>Conclusion</p> <p>We conclude that poor metabolic control is associated with significant pathological changes in the gastric wall that affect all major components including muscle, neurons and ICC. Severe symptoms can occur in the absence of these changes, however and may reflect vagal, central or hormonal influences. Gastroparesis is therefore likely to be a heterogeneous disorder. Careful molecular and pathological analysis may allow more precise phenotypic differentiation and shed insight into the underlying mechanisms as well as identify novel therapeutic targets.</p