Rows Of Wells Research Articles

Biofilm Development by Mycobacterium avium Complex Clinical Isolates: Effect of Clarithromycin in Ultrastructure.

The Mycobacterium avium complex includes the commonest non-tuberculous mycobacteria associated with human infections. These infections have been associated with the production of biofilms in many cases, but there are only a few studies about biofilms produced by the species included in this group. Three collection strains (M. avium ATCC25291, M. intracellulare ATCC13950, and M. chimaera DSM756), three clinically significant strains (647, 657, and 655), and three clinically non-significant ones (717, 505, and 575) of each species were included. The clinical significance of the clinical isolates was established according to the internationally accepted criteria. The biofilm ultrastructure was studied by Confocal-Laser Scanning Microscopy by using BacLight Live-Dead and Nile Red stains. The viability, covered surface, height, and relative autofluorescence were measured in several images/strain. The effect of clarithromycin was studied by using the technique described by Muñoz-Egea et al. with modifications regarding incubation time. The study included clarithromycin in the culture medium at a concentration achievable in the lungs (11.3 mg/L), using one row of wells as the control without antibiotics. The bacterial viability inside the biofilm is expressed as a percentage of viable cells. The differences between the different parameters of the biofilm ultrastructure were analyzed by using the Kruskal-Wallis test. The correlation between bacterial viability in the biofilm and treatment time was evaluated by using Spearman's rank correlation coefficient (ρ). The strains showed differences between them with all the studied parameters, but neither a species-specific pattern nor a clinical-significance-specific pattern were detected. For the effect of clarithromycin, the viability of the bacteria contained in the biofilm was inversely proportional to the exposure time of the biofilm (ρ > -0.3; p-value < 0.05), excluding two M. chimaera strains (M. chimaera DSM756 and 575), which showed a weak positive correlation with treatment time (0.2 < ρ < 0.39; p-value < 0.05). Curiously, despite a clarithromycin treatment of 216 h, the percentage of the biofilm viability of the strains evaluated here was not less than 40% at best (M. avium 717). All the M. avium complex strains studied can form biofilm in vitro, but the ultrastructural characteristics between them suggest that these are strain-specific characteristics unrelated to the species or the clinical significance. The clarithromycin effect on MAC species is biofilm-age/time-of-treatment-dependent and appears to be strain-specific while being independent of the clinical significance of the strain.

Estimation of L-carnitine levels in diabetic completely edentulous patients for implant diagnosis: A cross-sectional study

Background: Carnitine is effective in preventing the accumulation of end products related to lipid peroxidation due to its anti-inflammatory and antioxidant effects. Carnitine also exerts a significant anti-inflammatory role through the downregulation of the nuclear factor kappa beta pathway, which leads to a decrease in the expression of pro-inflammatory cytokines. The aim of the study was to estimate the L-carnitine (L-C) levels in diabetic completely edentulous patients. Materials and Methods: A cross-sectional study was conducted after the selection of 60 samples based on the inclusion and exclusion criteria. The collected saliva samples were utilized to measure the levels of L-C using the sandwich enzyme-linked immunosorbent assay (ELISA) method. One hundred microliters of sample was applied to a particular row of wells and incubated for an hour as part of the sandwich ELISA procedure. After the wells had been cleaned, a second batch of monoclonal L-C was added, and they were once more incubated for an hour. The horseradish peroxidase substrate was then applied after washing the second batch as well. To allow the blue-to-yellow color transition, the wells were kept steady. Following the observation of the color shift, the OD was measured, and the concentration was determined using the sandwich ELISA kit's standard curve as an intercept. The data were statistically analyzed using the independent t-test (significant level P &lt; 0.05) and were tabulated. Results: The L-C levels have higher levels in nondiabetic patients than in diabetic patients. The difference in the baseline mean value between the groups was statistically significant (P = 0.00). Although it is statistically significant (P = 0.00), the mean value for diabetic individuals is 0.19 as opposed to 0.29 for nondiabetic patients. Conclusion: Based on the findings, it can be concluded that L-C improves insulin sensitivity and glucose disposal in diabetic completely edentulous patients.

Оптимизация интервалов замедлений при короткозамедленном взрывании вскрышных пород на разрезах Кузбасса

Introduction. The solution of the level maintaining problem of blasting negative impact on the environment and protected objects within acceptable values while simultaneously increasing the volume and intensity of preparation of overburden by drilling and blasting lies in the field of improving methods and means, as well as optimizing the parameters of blasting, including by determining the optimal values of deceleration intervals during short-delayed blasting of overburden. Research methods and materials. To solve this problem, an algorithm was developed implemented in a software package that allows calculating the number of wells being blown up simultaneously; modeling and visually demonstrating the development of an explosion; calculating combinations of values of deceleration values of short-delayed blasting between rows of wells and between wells in a row; quantifying the quality of the found combination of values of deceleration values of short-delayed blasting and visually displaying how much the mass explosion proceeds uniformly in time, as well as the total duration of the explosion. Research results. The calculation of deceleration values combinations of short-delayed blasting between rows of wells and between wells in a row is performed depending on the number of rows of wells and the number of wells in a row for the selected number of wells exploding simultaneously. It is established that with an increase in the number of rows of wells, the number of points corresponding to a particular number of wells being blown up simultaneously (in the interval of 20 ms) decreases. At the same time, the sets of points corresponding to each next step of increasing the number of rows partially belong to the set of points corresponding to the previous step, and solutions for different values of the number of wells in a series with a constant number of rows are mutually exclusive. It is shown that with an increase in the values of the deceleration intervals, the quality of the solution increases in the case of a constant number of wells exploding simultaneously. Conclusion. The choice of optimal deceleration intervals during drilling and blasting operations is an effective way to control the seismic impact on protected objects. Increasing the deceleration to a value that ensures the formation of additional exposed surfaces is effective from the point of view of providing a complex effect as a result of an explosion, as a combination of the possibility of obtaining the required quality of rock crushing and reducing the seismic impact on protected objects. Resume. The developed algorithm, implemented in the software package, makes it possible to efficiently calculate the number of wells exploding simultaneously, find the optimal combination of values of deceleration values, quantify the quality of the found combination. For a more adequate assessment of the expected seismic impact, it is necessary to calculate the ratio of the duration of the period of non-maximum intensity of explosions to the total duration of explosions, expressed as a percentage. The larger the calculated value, the less seismic impact the explosion will have when comparing explosions with an equal number of wells exploding simultaneously.

МОДЕЛИРОВАНИЕ ВОДОЗАБОРОВ В ПОЛУОГРАНИЧЕННОМ ПЛАСТЕ В ЦЕЛЯХ УПРАВЛЕНИЯ МЕЛИОРАТИВНЫМ РЕЖИМОМ ОКРЕСТНОСТИ ОТКРЫТОГО КОЛЛЕКТОРА

This article presents materials on the creation of a model of water intakes in a semi-limited reservoir in order to study the regularities of failures of an open collector-drainage network, as well as the impact of a decrease in their performance on the reclamation state of irrigated lands, taking into account the regulation of the reclamation regime of the soils of the Shuruzyak collector in the Syrdarya region. The authors consider a single well and a group of interacting wells located in any way, as well as a linear row of wells, of a very significant length near the Shuruzyak collector. The performed calculation shows an estimate of the balance with the identification of individual constituent sources, which ensure the flow rate of wells, which is most reliably produced by constructing filtration grids (graphically or based on modeling) using the method of adding currents. When calculating onshore water intakes in all the considered schemes, including those where the water intake is provided entirely by the inflow of groundwater from the coastline, the effect of an open collector must be taken into account. A decrease in the level under the action of pumping out of wells in such conditions should theoretically occur at all points of the formation, not only in the “capture zone”, limited by the neutral streamline, but also outside it, up to the collector.

Improving the production technology of drilling and blasting operations by blasting of high ledges

In modern economic conditions, the issue of improving the efficiency of mining enterprises is very relevant. One of the key processes isdrilling and blasting operations (DBO), which determine the efficiency of the entire complex of mining operations. One of the main methods of controlling the explosion energy is the diameter of the blast wells. According to the recommendations of prof. B N Kutuzov the diameter of blast wells is correlated with the fracturing and strength of the exploding rocks. With increasing blockage and rock strength to achieve the required quality of explosive crushing preference is given to drilling equipment with a small diameter of wells. By blasting of high ledges, especially large-block rocks with a strength coefficient of more than 15 on the M M Protodyakonov scale; the use of high-performance drilling equipment for drilling small-diameter blast wells is difficult. This is due to the fact that the calculated value of the resistance line along sole (RLAS) does not pass the safety condition for drilling the first row of wells. In this regard, the paper proposes and justifies the use of extensions of the lower parts of wells using mechanical expanders.

An underground barrier of locally resonant metamaterial to attenuate surface elastic waves in solids

The low frequency of seismic waves severely limits the regulation of wave propagation in earthquake protection engineering applications. In recent years, locally resonant metamaterials have been introduced for seismic wave attenuation. A barrier based on locally resonant metamaterials consisting of rows of wells is proposed to reduce the transmission of Rayleigh waves during propagation, achieving earthquake protection. First, comparisons are made between the wells of the metamaterial, empty wells, solid steel wells, and a continuous steel wall. It is evident that locally resonant metamaterials exhibit better performance than that of the other materials. Simulations of the relationships between the attenuation of Rayleigh waves and the depth, number of rows, and working frequency of the wells are presented. With a barrier of ten rows of wells, where the diameter of each well is less than one-twentieth of the wavelength of the Rayleigh wave and the depth of the wells is nearly four-fifths of the wavelength, the maximum attenuation reaches up to 16.2 dB when all the wells share the same working frequency, and the bandwidth is broader, but the maximum value is less when the rows have different working frequencies. Depending on the demand for a higher value or a broader bandwidth of the Rayleigh wave attenuation, this barrier promotes flexible and achievable improvements by adding rows or decentralizing the working frequencies of the wells. The vast potential of seismic wave attenuation from locally resonant metamaterials is anticipated in the future.

Design and Study of Intensive Track Laying System for Single Hole and Double Road in Open Cut Station

This paper takes Qingdao subway station as an example, considers reducing the cycle of track laying on the whole line, and adds rails and wells under the existing envelope structure. The single-track row of wells and a double-line entrance to the crossing are proposed. The analytical calculations and numerical simulation methods were used to check the mechanical condition of the station envelope and the main structure of the station under the rails. The research results show that the track laying base can be laid out in the enclosed open excavation station, and a series of problems such as land occupation coordination have been solved, and the period benefit is significant. This scheme can ensure the structural safety before the entrance of the rail row well is closed, and the position of the rail side frame below the middle plate of the station satisfies the requirements of the laying limit. This method has a novel design idea, has high application and promotion value, and provides a good reference for the design and construction of open-cut subway stations.

Digital Colorimetry of Non-steroidal Anti-inflammatory Drugs: Identification Using Principal Component Method

Introduction . Digital colorimetry is one of the available and simple methods that can be used for the rapid detection of low-quality drugs. The main limitation of the method is its lack of selectivity. To increase the selectivity, the use of molecular sensors is proposed. Molecular sensors are substances that change color during physicochemical interaction with the analyte. Digital colorimetric analysis using a set of sensors allows one to obtain a large amount of information about the sample, however, such a significant amount of data is rather difficult to interpret and use for rapid assessment of the composition of the drug. In addition, the use of a large set of sensors significantly increases the level of information noise. To reduce the influence of the noise component, as well as to reduce the dimensionality of the data, it is advisable to use chemometric algorithms, in particular, the method of principal components (principal component analysis, PCA). It is shown that the using of PCA will make it possible to replace 24 values of the luminosity of color channels with 2-3 numerical values of the main components without loss of analytical information. Aim . Aim of our investigation is the development of a new approach to identifying non-steroidal anti-inflammatory drugs using multisensory digital colorimetry by the principal component method. Materials and methods . The analysis was performed in 96-well transparent polypropylene plates with flat bottom ( Thermo Fischer Scientific , USA, № 430341). 100 μl of the correspond-ing sensor and 100 μl of alcohol solutions of non-steroidal anti-inflammatory substance sub-stances were consistently added to the wells of the plate. Sensor solutions were added to a separate row of wells for comparison without adding substance solutions (intact wells). After adding solutions of the substance, the plate was sealed with a film, shaken on a PST-100HL plate shaker (BioSan, Latvia) for 5 minutes and left for 20 minutes to complete the reaction. To obtain raster images an Epson Perfection 1670 office flatbed scanner (CCD matrix) with a removable cover was used. The difference in the lightness of the color channels between the analyte well and the intact well was used as an analytical signal. The obtained digital images of the cells were processed in the ImageJ program using the RGB 24 bit color model (8 bits per channel). Results and discussion . It is shown that the use of chemometric algorithms for processing the results of multisensor colorimetric analysis allows to use the entire data array in obtaining an-alytical information, and not just the lightness values of individual channels of some sensors. The method of principal components allows you to simultaneously get rid of the noise com-ponent of the colorimetric signal and highlight the most sensitive sensors for this sample. The adequacy of the proposed combined approach is confirmed by the identification of active sub-stances in 5 drugs of the group of non-steroidal anti-inflammatory drugs. Conclusion . The approach proposed in this work can be successfully applied as an express and available way to assess the authenticity of medications of the group of non-steroidal anti-inflammatory drugs.

EFFICIENT LOCATION OF THE ROWS OF INJECTION AND PRODUCTION WELLS IN HIGH VISCOSITY OIL DEPOSITS WITH EXTENDED RESERVOIR TIGHTNESS ZONES

Background A lot of works are devoted to the issues of injection and production wells location in a zonal inhomogeneous permeable reservoir. Researchers are trying to understand how the location of wells in reservoir zones with different permeability affects oil recovery efficiency. This issue is particularly acute for development systems with maintaining reservoir pressure. It has been established that the location of injection wells in low-permeable zones, and production in the high-permeable zones of the reservoir contributes to increasing the coverage of the impact. Moreover, even in the conditions of a partially developed reservoir, the transformation of the existing development system according to the above principle has significant potencies for increasing the oil recovery factor (ORF). Another actual problem is the study of the effect of extensive high-permeable inclusions (faults, reservoir tightness zones) on the effectiveness of regular development systems. It is concluded that the development systems with different location of production and injection wells with regard to fault lines are unequal. This assumption requires not only qualitative, but also quantitative evaluation. Aims and Objectives: Consider the dependence of oil recovery on the location and orientation of the rows of production and injection wells with regard to fault lines. Results 1. It was established that the location of the rows of wells parallel to the fault line (variants 1, 2, 5, 6) allows to achieve a higher ORF compared to placing the rows of wells perpendicular to the fault line (variant 3). 2. Location a row of injection wells in the raised part of the reservoir is less effective than their location in the lower part. The most effective is the location of a row of production wells in the zone of decompression of the reservoir, and the rows of injection wells - outside the zone of decompression. This variant of well row location has the maximal withdrawal rate and the highest ORF value.

ANTIPLAQUE EFFICACY OF GANODERMA LUCIDUM TOOTHPASTE - AN IN VITRO STUDY

Objective: The objective of the study was to evaluate the efficacy of Ganoderma lucidum toothpaste as an antiplaque agent and to compare its efficacy with herbal toothpaste and mouthwash.Methods: Pooled saliva was collected in a sterile container from the volunteers after taking the consent. Tissue culture plate with 12 (3 × 4) wells was chosen. Pooled saliva of 20 mL was added to each well using the micropipette and was kept in the incubator at 37°C for 72 h. After 72 h, saliva was removed without touching the walls or the base of the wells. Each row was treated either with slurry prepared with Ganoderma/herbal/Colgate total toothpaste or herbal/chlorhexidine mouthwash/distilled water. One row of wells was kept as a control using erythrosine dye. After 30 s, all the wells were rinsed with distilled water. Erythrosine dye was added to all the wells, kept for 30 s, and rinsed with distilled water. The tissue culture plate was kept in the ELx800MS machine (ELISA reader) which was set at 540 nm, and the readings were obtained.Results: The results showed that G. lucidum toothpaste slurry reduced plaque than herbal and chlorhexidine mouthwash. However, there was no significant difference in plaque reduction between herbal and G. lucidum toothpaste slurries.Conclusion: The present study concluded that G. lucidum had better antiplaque efficacy than herbal toothpaste, herbal mouthwash, and chlorhexidine mouthwash.

Chemical and mechanical clogging of groundwater abstraction wells at well field Heel, the Netherlands

Well field Heel, in the south east of the Netherlands, consists of a row of wells drilled in an anoxic pyrite-containing aquifer alongside a former gravel pit, which now serves as a recharge basin, where water is actively aerated. All wells are seriously affected by chemical (screen slot) and/or mechanical (well bore) clogging. The objective of this study is to explain this combined occurrence. A combination of chemical, hydraulic and well-maintenance data indicate three groundwater quality types: (1) oxic basin water, (2) anoxic iron-containing basin water after oxidation of the traversed aquifer, and (3) deeply anoxic native groundwater. Wells abstracting a mixture of oxic basin water and anoxic basin water and/or native groundwater experience chemical well clogging, whereas wells abstracting (only or partly) native groundwater are vulnerable to mechanical well clogging. In the end, after oxic basin water has completely oxidized the traversed the aquifer, only two groundwater quality types will be present. Wells abstracting only oxic basin water will show no clogging, and wells abstracting a mixture of native groundwater and oxic basin water will experience chemical and possibly also mechanical well clogging. In this reasoning, the sequence in abstracted groundwater quality types coincides with a sequence in well clogging: from mechanical to chemical to no clogging. As well field Heel is situated in sloping terrain, the interplay between regional hydraulic gradient and different water qualities results in one-sided chemical clogging in the upper part of the well screen during abstraction, and in the lower part during the resting phase.

Scaling and Pedotransfer in Numerical Simulations of Flow and Transport in Soils

Flow and transport parameters of soils in numerical simulations need to be defined at the support scale of computational grid cells. Such support scale can substantially differ from the support scale in laboratory or field measurements of flow and transport parameters. The scale dependence of flow and transport parameters essentially precludes the direct use of measured or pedotransfer-estimated parameter values in numerical simulations. The hypothesis of this work was that a support-based scaling law can be introduced that can convert pedotransfer-estimated saturated hydraulic conductivity values into values to be used over grid cells for finite-element-based simulations of water flow and tracer transport in variably saturated soils. A 4-month-long experiment was conducted at the USDA–ARS experimental site where Cl− as a tracer was applied with a pulse of irrigation water and its transport in groundwater and variably saturated shallow coarse-textured soils was monitored in two rows of wells on a daily basis. The HYDRUS-3D software was used to set and calibrate the Richards model for flow simulations and the convective–dispersive equation for transport simulations. Saturated hydraulic conductivity values were estimated with class pedotransfer functions derived from the USDA database containing results of about 1000 measurements in soils of different textures and bulk densities. A power law scaling for the saturated hydraulic conductivity was suggested based on literature data. When only two parameters of the scaling law rather than nine values of hydraulic conductivity from nine soil materials were calibrated, using the scaled saturated hydraulic conductivity values resulted in an accuracy of simulations that was similar to the accuracy of the calibrated model results. Upscaling of pedotransfer-estimated saturated hydraulic conductivities can provide reasonable estimates for numerical flow and transport modeling in variably saturated soils.

High-throughput fluorescence assay for membrane-protein interaction

Membrane-protein interaction plays key roles in a wide variety of biological processes. Although various methods have been employed to measure membrane binding of soluble proteins, a robust high-throughput assay that is universally applicable to all proteins is lacking at present. Here we report a new fluorescence quenching assay utilizing enhanced green fluorescence protein (EGFP)-fusion proteins and a lipid containing a dark quencher, N-dimethylaminoazobenzenesulfonyl-phosphatidylethanolamine (dabsyl-PE). The EGFP fluorescence emission intensity showed a large decrease (i.e., >50%) when EGFP-fusion proteins bound the vesicles containing 5 mol% dabsyl-PE. This simple assay, which can be performed using either a cuvette-based spectrofluorometer or a fluorescence plate reader, allowed rapid, sensitive, and accurate determination of lipid specificity and affinity for various lipid binding domains, including two pleckstrin homology domains, an epsin N-terminal homology domain, and a phox homology domain. The assay can also be applied to high-throughput screening of small molecules that modulate membrane binding of proteins.

Quality assurance phantom for digital dental imaging

The purpose of this research was to develop a simple quality assurance phantom that could be used for the initial calibration and follow-up testing of commercially available intraoral digital imaging systems. A radiographic phantom was constructed that contains a calibrated step wedge for measuring dose response, an etched pattern of slits in a metallic background for measuring the spatial resolution in line pairs per millimeter, and 2 rows of wells of varying diameter and depth in an acrylic background for contrast-detail analysis. Quality assurance protocols were developed and validated. The quality assurance phantom provides a method of assessing a digital intraoral imaging system by measuring the sensitivity and dynamic range, the contrast/detail detectability and the spatial resolution. This quality assurance phantom can serve as an effective means to calibrate and monitor the performance characteristics of a digital dental intraoral imaging system.

Actions of β-Amyloid Protein on Human Neurons Are Expressed through the Amylin Receptor

Disruption of neurotoxic effects of amyloid β protein (Aβ) is one of the major, but as yet elusive, goals in the treatment of Alzheimer's disease (AD). The amylin receptor, activated by a pancreatic polypeptide isolated from diabetic patients, is a putative target for the actions of Aβ in the brain. Here we show that in primary cultures of human fetal neurons (HFNs), AC253, an amylin receptor antagonist, blocks electrophysiological effects of Aβ. Pharmacological blockade of the amylin receptor or its down-regulation using siRNA in HFNs confers neuroprotection against oligomeric Aβ-induced caspase-dependent and caspase-independent apoptotic cell death. In transgenic mice (TgCRND8) that overexpress amyloid precursor protein, amylin receptor is up-regulated in specific brain regions that also demonstrate an elevated amyloid burden. The expression of Aβ actions through the amylin receptor in human neurons and temporospatial interrelationship of Aβ and the amylin receptor in an in vivo model of AD together provide a persuasive rationale for this receptor as a novel therapeutic target in the treatment of AD.

Strain array for cell culture: cyclic strain affects epithelial cell spreading

We have designed, fabricated and characterized a strain array (6 mm well plate format) for cell culture that applies different strain to cells plated in each row of wells on the device. This device is capable of applying 0%, 2%, 4%, 7% or 17% strain to distinct samples with separate perfusion paths using a pressure difference of 10kPa. Our device has 25 wells but mimics the geometry of a standard 96‐well plate (for compatibility with automated plate readers and other technologies) and leaves samples easily accessible to assay. Further, samples experiencing different strain fields have separate perfusion pathways. These capabilities are useful in experiments to examine mechanotransduction mechanisms, specifically sensitivity to applied strain. Madin‐Darby Canine Kidney epithelial cells were attached on the device for 3 hrs then cyclically strained at 1Hz. Cells exhibited different patterns of spreading and localization of GFP‐tagged vinculin in response to strain levels over time.This work is funded by NSF EFRI CBE0735551, NIH R21 HL089027, and CIRM RC1‐00151‐1. CS is funded by the Smittcamp Graduate Fellowship of the Stanford Cardiovascular Institute and an NSF Graduate Research Fellowship.

Merging Microfluidics with Microtitre Technology for More Efficient Drug Discovery

Detecting multiple components from a single red blood cell (RBC) sample within a flow-based system and in less than 20 minutes will enable improved in vitro determinations of drug efficacy and cellular response to administered drugs. Here, an example of an improved in vitro measurement involving iloprost, a pharmaceutical reported to improve blood flow, has been determined by incorporating multiple cell types onto a single device. The method allows fluid flow to address individual rows of wells contained within an 18-well microfluidic array that serves as a precursor to a 96-well micro-titre plate device. The ability to better mimic the in vivo circulation by incorporating the flow of blood components, coupled with simultaneous detection and laboratory automation in place for micro-titre plates, suggests that the microfluidic array presented here will allow for improved mechanistic drug research studies. Utilizing fluorescence microscopy, concentrations of multiple metabolites present within the RBC can also be determined using the microfluidic array. The current progress towards using this device for personalized medicine is presented here.

A Pitfall of the 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethonyphenol)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) Assay due to Evaporation in wells on the Edge of a 96 well Plate

The 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethonyphenol)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) calorimetric assay is replacing the traditional 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay as a fast, one-step assay of cell viability. We have observed that evaporation of the outer wells of a 96 well plate increases the absorbancy by 52% compared to the inner wells. Filling the outer 2 rows of wells with media and replacement of the media prior to addition of the MTS reagent will, however, correct this inaccuracy.

A Simple, Efficient, and Economical Method for Recovering DNA from Agarose Gel

A simple method of recovering DNA from agarose gel that is fast, inexpensive, and friendly both to operators and environment is described. Two rows of wells are made in an agarose gel, and a DNA sample is loaded into the well nearest to the negative pole for separation by electrophoresis. Recovery is accomplished by pipetting the DNA‐containing TAE buffer from the well near the positive pole after target DNA fragments have migrated into the well. A recovery rate of up to 94 ± 2.3% was observed with this method.

Memory for Spatial Location: Role of the Hippocampus in Mediating Spatial Pattern Separation

A paradigm based on measuring short-term memory for spatial location information as a function of spatial similarity between distal cues was developed to examine the role of pattern separation in the modulation of short-term memory for spatial information. A delayed-match-to-sample for spatial location task using a dryland version of the Morris water maze was used to assess spatial pattern separation in male Long-Evans rats. In the sample phase, animals were trained to displace an object that covered a baited food well in one of 15 spatial locations along a row of food wells perpendicular to a start box. In the ensuing choice phase, the animal was allowed to choose between two objects identical to the sample phase object. One covered the same baited food well as did the object in the study phase (correct choice), and another foil object (incorrect choice) covered a different unbaited food well along the row of wells. Five spatial separations were randomly used to separate the correct object from the foil object. After reaching a criterion before the operation, animals were given either hippocampal or cortical control lesions. In trials after the operation, control animals matched their performance before the operation across all spatial separations. In contrast, hippocampal-lesioned animals displayed impairments across all spatial separations with the exception of the longest (105 cm) spatial separation. The results suggest that the hippocampus may serve to separate incoming spatial information by temporarily storing one place separate from another. It is proposed that hippocampal lesions decrease efficiency in pattern separation, resulting in impairments in trials with increased spatial similarity among working-memory representations.