Bottom Chambers Research Articles

Cardiac Arrhythmia Prediction and Prevention of Heart failure using PCG(PhonoCardioGram) and CNN

Abstract: Arrhythmias are abnormal cardiac rhythms. According to WHO, in today's world 31% of deaths occur due to Cardiac Arrhythmia. Life-threatening arrhythmias including Ventricular Tachycardia (VT) and Ventricular Fibrillation are frequent causes of cardiac arrest (VF). The sinus node controls the heart's rhythm by triggering an electrical signal that goes through the heart, causing the heart to beat and circulate blood around throughout. The heart does not pump efficiently if there is too much electrical activity in the top or bottom chambers. Shortness of breath, fainting, an abrupt loss of heart function, and unconsciousness are the most common signs of Arrhythmia, which can result in death within minutes unless the victim receives emergency medical treatment to restart the heart. The purpose of this research is to use the CNN and VGG16 models in conjunction with data augmentation and picture pixel creation to diagnose cardiac arrhythmias using PCG signals. For greater efficiency, phonocardiography (PCG) is also investigated. The majority of arrhythmia detection and classification methods rely solely on surface ECG analysis. So, to improve the efficiency of heart diagnostics, an algorithm is devised that relates to wavelet analysis at several resolutions combining temporal and wavelet properties of Electrocardiogram and Phonocardiogram, as well as ElectrocardiogramPhonocardiogram interactions. We want to be able to classify phonocardiograms (PCGs) or heartbeat recordings. as "normal" or "abnormal" in order to identify individuals who will require further diagnosis. The main concept is to transform each cardiac sound recording (wav file) into a spectrogram image and train a CNN model on that picture. We will then be able to categorize a fresh PCG recording as normal or abnormal.

Movable Layer Device for Rapid Detection of Influenza a H1N1 Virus Using Highly Bright Multi-Quantum Dot-Embedded Particles and Magnetic Beads.

Preventing the rapid spread of viral infectious diseases has become a major concern for global health. In this study, we present a microfluidic platform that performs an immunoassay of viral antigens in a simple, automated, yet highly sensitive manner. The device uses silica particles embedded with highly bright quantum dots (QD2) and performs the immunoassay with a vertically movable top layer and a rotating bottom layer. Through the motion of the layers and the surface tension in the liquids, reagents move from top chambers to bottom chambers and mix homogeneously. A tip in the top layer with a mobile permanent magnet moves the immune complexes comprising the magnetic beads, virus particles, and QD2 between the bottom chambers. In this way, our automated device achieves a highly sensitive magnetic bead-based sandwich immunoassay for the influenza A H1N1 virus within 32.5 min. The detection limit of our method is 5.1 × 10−4 hemagglutination units, which is 2 × 103 times more sensitive than that of the conventional hemagglutination method and is comparable to PCR. Our device is useful for the rapid and sensitive detection of infectious diseases in point-of-care applications and resource-limited environments.

Rapid Truck Loading for Efficient Feedstock Logistics

A multi-bale handling unit offers an advantage for the efficient hauling of round bales. Two empty racks on trailers are left at a satellite storage location for loading while a truck tractor delivers two loaded racks to the biorefinery, thus uncoupling the loading and hauling operations and increasing the efficiency of both. The projected 10 min trailer exchange time equals the projected 10 min unload time at the biorefinery achieved by lifting off the two full racks and replacing them with two empties, a technology adapted from the container shipping industry. A concept is presented for a bale loader that latches onto the rack/trailer and loads bales into the bottom tier chambers. This machine will load 10 bales into the rack on the front trailer by attaching on to the front of the trailer and 10 bales into the rear trailer by attaching onto the rear. A telehandler removes bales from single-layer storage and places them in the bale loader to load the bottom tier compartments. The top tier compartments are loaded directly from the top. Expectations are that an experienced operator can average 9 loads in a 10 h workday, and load-out cost is estimated as 3.61 USD/Mg, assuming the average achieved load-out productivity over annual operation is 60% of optimum productivity (24 Mg/h) equal to 14.4 Mg/h. Cost increases to 4.81 USD/Mg when the productivity factor drops to 45%, and cost is 3.09 USD/Mg for a factor of 70%.

Integrated and finger-actuated microfluidic chip for point-of-care testing of multiple pathogens

The integration of gel-based loop-mediated isothermal amplification (gLAMP) and finger-actuated microfluidic chip (μFAchip) was developed for the simultaneous detection of various different types of bacterial pathogens. The developed μFAchip consisted of three PDMS layers attached together by two adhesive tapes. Multiple chambers in the top PDMS layer were used for sample preparation, and the corresponding chambers in the bottom PDMS layer was used for long-term storage of LAMP reagents without DNA templates. The thin PDMS layer in the middle contained cross-shaped cuts as finger-actuated valves for fluid control. To reduce operation steps on the chip, such as pipetting and manipulation of samples, Whatman CloneSaver card was pre-embedded in the top chambers for on-chip DNA extraction and purification. Upon a simple press on the top layer, the finger-actuated valve was opened up, allowing DNA samples on the top layer flow into the bottom reaction chambers for gLAMP reaction. For POCT applications, on-chip LAMP reaction and imaging were conducted on a miniaturized peltier heater and a portable fluorescence imaging system respectively. Under the optimized condition, multiple pathogens were detected simultaneously with high selectivity and sensitivity (as low as 1.6 cells). The developed μFAchip provided a rapid and easy-to-operate platform for gLAMP-based pathogen detection, with the potential for in-field detection, especially in areas with limited resources.

Performance Analysis of 2 in 1 Parabolic Trough Collector for Both Hot Water and Hot Air Production for Domestic Household Applications

Parabolic trough collectors (PTC) are solar thermal energy collectors designed to capture the sun’s direct radiation over aperture area and concentrate it onto a focal point. Parabolic shaped mirrors are used to focus the solar radiation on the pipe that carries water to heat it. The concentrated heat from the parabolic collector heats up the water and helps in producing hot water which can be used domestically. Drying is one of the important and energy consuming processes. Especially foragricultural product processing open yard drying is widely adapted, without proper hygienic condition. The presently designed cost effective two in one PTC setupcanheat water and air simultaneously. In the box shaped structure the hot water isgenerated at the top of the box. The unused absorbed heat on the collector is used to heat the air which is passed via bottom chambers. As a result, hot water (60°C) and hot air (45°C) can be obtained which is used mainly for heating purpose. Manual tracking type of design is chosen for cost effectiveness and simplicity in structure. This Combined water and air heating design improves the total efficiency of the system up to 4.3% when compared with the conventional PTC design. In addition, the emission reduction of 1 kg of CO2/day can be achieved and simple payback period is 2 years when compared to electric heaters which can be easily affordable by common man.

Experimental and numerical study of oxy‐methane flames in a porous‐plate reactor mimicking membrane reactor operation

The work investigates the reacting flow field, oxy-methane flame characteristics and location, and the species distributions in a porous-plate reactor mimicking the operation of oxygen transport membrane reactors (OTMRs). The study was performed experimentally and numerically considering ranges of operating equivalence ratio, from 0.5 to 1.0, and CO2 concentrations in the total oxidizer flow (O2 and CO2), from 0% to 55% (by Vol). Oxygen was supplied through a slightly pressurized top and bottom chambers to cross the two porous plates to the central chamber, where a premixed mixture of CH4 and CO2 is introduced. ANSYS Fluent 17.1 software was used to solve for conservation and radiative transfer equations in the full three-dimensional (3-D) domain. The modified Westbrook-Dryer (Oxy-WD) two-step reduced mechanism for oxy-methane combustion was adapted for the calculations of chemical kinetics. The captured flame shapes using a high-speed camera were compared with the calculated ones, and the results showed good agreements. At fixed equivalence ratio, elongated flames were obtained at higher CO2 concentrations due to the increase in the mainstream Reynolds number and reduction in reaction rates, which delays the completeness of combustion. At fixed CO2 concentration, the increase in equivalence ratio resulted in more compact and intense flames. The effective mixing and flame stability resulted in complete fuel conversion under stoichiometric condition. Stable flames were located between the two porous plates at reasonable distance. This perfect flame location prevents the thermal fracture of the membranes and improves their oxygen permeation flux, resulting in better combustion characteristics when the results are projected on the case of OTMRs. This implies efficient and safe applicability of the OTMRs by the condition that membranes can provide sufficient oxygen flux for complete combustion. A warm outer recirculation zone (ORZ) was created beside each porous plate, which helps anchoring the flame at the leading edge of the porous plate. The range of temperature within the ORZ was 800 to 1600 K, which lies in the operability limits of membranes for the case of OTMRs. The effective complete mixing and flame stability resulted in complete fuel conversion under stoichiometric condition. The temperature and species distributions within the reactor are presented in detail over wide ranges of operating conditions. The results recommended the reactor operation under stoichiometric combustion condition based on performance and economic points of views. The results are promising when projected on the application of the OTMRs under oxy-combustion conditions for clean and efficient energy production.

Internal loading of phosphorus in western Lake Erie

Abstract This study applied eight techniques to obtain estimates of the diffusive flux of phosphorus (P) from bottom sediments throughout the western basin of Lake Erie. The flux was quantified from both aerobic and anaerobic incubations of whole cores; by monitoring the water encapsulated in bottom chambers; from pore water concentration profiles measured with a phosphate microelectrode, a diffusive equilibrium in thin films (DET) hydrogel, and expressed pore waters; and from mass balance and biogeochemical diagenetic models. Fluxes under aerobic conditions at summertime temperatures averaged 1.35 mg P/m2/day and displayed spatial variability on scales as small as a centimeter. Using two different temperature correction factors, the flux was adjusted to mean annual temperature yielding average annual fluxes of 0.43–0.91 mg P/m2/day and a western basin-wide total of 378–808 Mg P/year as the diffusive flux from sediments. This is 3–7% of the 11,000 Mg P/year International Joint Commission (IJC) target load for phosphorus delivery to Lake Erie from external sources. Using these average aerobic fluxes, the sediment contributes 3.0–6.3 μg P/L as a background internal contribution that represents 20–42% of the IJC Target Concentration of 15 μg P/L for the western basin. The implication is that this internal diffusive recycling of P is unlikely to trigger cyanobacterial blooms by itself but is sufficiently large to cause blooms when combined with external loads. This background flux may be also responsible for delayed response of the lake to any decrease in the external loading.

Bone Marrow Derived Mesenchymal Stem Cells from Splenic Marginal Zone Lymphoma Patients Exhibit Altered Proliferative Potential and B Lymphocyte Immunomodulatory Properties

Splenic marginal zone lymphoma (SMZL) originates from the neoplastic transformation of mature B-lymphocytes. However, there is a concurrent high prevalence of bone marrow (BM) infiltration, suggesting that BM microenvironment dynamics could have a potential involvement in disease pathology. In this regard, we aim to characterise BM derived mesenchymal stem cells (MSCs), since they comprise key components of the BM hematopoietic stroma, in order to investigate if MSCs show altered properties in SMZL patients compared to healthy controls.BM MSCs were isolated from 8 SMZL patients and 10 age- and sex-matched healthy controls. MSCs were in vitro expanded and re-seeded for a total of 5 passages (P). The colony forming unit-fibroblast (CFU-F) assay was used for the estimation of MSC frequency within the BM mononuclear cell (BMMC) fraction. Ex-vivo expanded MSCs were phenotypically characterized by flow cytometry (FC) using appropriate markers. In vitro differentiation to adipocytes and osteoblasts was assessed by cytochemical stains. The proliferative potential of ex vivo expanded MSCs was evaluated by Methyl Triazolyl Tetrazolium (MTT)-based assay and survival characteristics were studied using FC and 7-Aminoactinomycin D (7-AAD) staining. To assess the effect of patient MSCs on B cell growth, B cells were immunomagnetically isolated (Miltenyi Biotec GmbH, Germany) from peripheral blood (PB) of normal individuals, labeled with carboxy fluorescein succinimidyl ester (CFSE; Gibco Invitrogen, Paisley, Scotland) and subsequently cultured in the absence or presence of confluent layers of allogeneic BM-MSCs from SMZL patients or normal controls in the presence of CpG oligonucleotide 2006 (Invivogen, France) and IL-2 (R&D Systems, Minneapolis, MN). In a separate set of experiments, B cell survival was evaluated via FC and 7-AAD staining, after co-culturing with BM-MSCs from patients or healthy donors. Finally, to study BM-MSC capacity to chemotactically attract B-cells, transwell migration assays were set. In the bottom chambers MSCs from patients or healthy individuals were grown until confluency and then isolated B cells from PB of either patients or controls were added into the upper chamber. Twelve hours later migrated cells were enumerated. Grouped data are expressed as means± 1 standard error of the mean (SEM).MSCs were successfully expanded from all participants in the study. Adherent cells from both study groups displayed the typical spindle-shape morphology and immunophenotypic analysis at the end of P2-P3-P4 demonstrated that cultures constituted of a homogeneous cell population, typically expressing CD29, CD44, CD73, CD90 and CD105 while being negative for CD14, CD34 and CD45. SMZL-derived MSCs were similar to their normal counterparts in the capacity to differentiate towards adipocytes and osteocytes as evidenced by Oil Red O and Alizarin Red staining, respectively. The frequency of MSCs within the BMMC compartment was significantly lower in patients as compared to healthy individuals (2.5±0.68/105 ΒΜΜCs and 7.23±0.6/105 ΒΜΜCs, respectively; P=0.0032) apparently due to the predominance of the lymphoma cells within patient BMMCs. SMZL MSCs displayed defective proliferative potential as compared to their normal counterparts at P2, as evidenced by the MTT assay (P<0.0001). To explore the influence of SMZL BM-MSCs in B cells survival we compared the viability of B cells isolated from the PB of healthy individuals cultured in medium alone to that of such cells co-cultured with either BM-MSCs derived from patients or normal controls. 43.85±1.46% of B cells cultured alone were apoptotic, while only 20.8±2.63% and 12±0.77% of B cells co-cultured with either normal MSCs or SMZL MSCs were apoptotic (P<0.0001 and P<0.0001, respectively). Notably patient MSCs confer a survival advantage in B cell viability over their normal counterparts (P=0.0374). Finally SMZL MSCs had a more potent chemotactic activity on B cells from healthy donors, as compared to MSCs from normal controls ( P<0.05).In conclusion we have shown for the first time that SMZL lymphoma MSCs are intrinsically defective in terms of proliferative potential and exert an altered modulation of B cell apoptosis and B cell chemotaxis. These preliminary results concerning the properties of SMZL MSCs merit further investigation and provide the theoretical background for exploring their potential implication in lymphomagenesis. DisclosuresNo relevant conflicts of interest to declare.

Cartilage Derived Morphogenetic Protein-2 Induces Cell Migration and Its Chondrogenic Potential in C28/I2 Cells.

Intervertebral disc degeneration is a major cause of low back pain. Previous researches have demonstrated local administration of signalling molecules as potential biological therapies for disc regeneration. Our laboratory has published encouraging results for effectiveness of injection of the cartilage derived morphogenetic protein-2 (CDMP-2) into ovine discs following annular injury. To elucidate the mechanisms underpinning these in vivo effects, this project aimed to investigate the potential of CDMP-2 on cellular migration, proliferation and extracellular matrix production in a human chondrocytic cell line. To evaluate cell motility, cells were seeded into Boyden chambers and CDMP-2 as a chemo-attractant or a stimulant was placed into either the bottom or top chambers respectively. Cells that had completed migration through the porous membrane were visualized by immunocytochemical staining and analysed using Image J. The effect of CDMP-2 on cell proliferation, proteoglycan and collagen production, as well as chondrogenic gene expression in human chondrocytic cell line C28/I2 was also examined. The results revealed that cells migrated significantly under the influence of CDMP-2 (200 ng/ml) stimulation compared to control (3-fold increase, p = 0.033) and demonstrated a significant chemotactic movement towards a solution of 200ng/ml CDMP-2 (>2-fold increase, p = 0.027). A 35% increase in C28/I2 proliferation was observed after CDMP-2 stimulation (p < 0.0001) compared to control, and in the presence of 100ng/ml CDMP-2, proteoglycan synthesis had an 8-fold increase (p = 0.048). Similarly, gene expression analysis demonstrated increased expression of aggrecan, collagen types II, X and XXVII, BMPR-1A and BMPR-2 when cells were treated with CDMP-2. The study shows that C28/I2 cells can migrate under the influence of CDMP-2 as a chemoattractant or migration stimulator, suggestive of an effect on chondrocytic cells in the intervertebral disc. Further, CDMP-2 can stimulate C28/I2 cells to proliferate and synthesize key extracellular matrix proteins.

The Laoguanshan Cemetery of the Han Dynasty in Tianhui Town, Chengdu City

AbstractIn July 2012 through August 2013, four earthen shaft pit tombs with wooden chambers were excavated in a cemetery of the Western Han Dynasty located in Tianhui Town, Jinniu District, Chengdu City. All of the four tombs, which had been looted and disturbed, were in similar sizes and same south-north orientation, and could be classified into two types by the presence and absence of the bottom chambers. 620 pieces of grave goods were unearthed from these tombs, most of which were lacquered wooden wares and pottery wares, as well as some bronzes and iron objects. The most important discoveries are the over 50 wooden tablets unearthed from M1, the jade seal and four loom models made of bamboo and wood unearthed from M2 and 920 (numbered) bamboo slips and lacquered human figurine with marks of meridians and acupuncture points unearthed from M3. The bamboo slips unearthed from M3 were mostly medical works, the contents of which were about medical theory, meridian and pulse, diagnoses, causes and symptoms of diseases and the treating of diseases, etc.

New Pneumatic Rubber Leg Mechanism for Omnidirectional Locomotion

This paper describes a new pneumatic rubber leg mechanism for omnidirectional locomotion. The new mechanism was adopted from a pneumatic balloon actuator where translation and bending motions are produced as a result of balloon deformation. It was constructed using five chambers: one on the top and centered over four bottom chambers arranged in a square. Several possible designs were simulated to achieve the optimal design using a non-linear finite element analysis that considered the design parameters and the geometrical and material non-linearity of the elements. Prototyping was then performed using a rapid and efficient silicone rubber molding fabrication process based on computer-aided design and manufacturing. The experimental results were in good agreement with the analytical results. In conclusion, we have established a new rubber leg mechanism with a high degree of freedom to realize omnidirectional locomotion for a soft robot base, delicate object conveyance, and / or microscope stage applications.

Does the presence of zooplankton influence growth and toxin production ofNodularia spumigena?

The ecological role of toxin production in cyanobacteria is still unknown. Here, we studied the potential effect of different zooplankton taxa and density on growth and toxin production of the cyanobacterium Nodularia spumigena. In this experiment, N. spumigena was exposed to three different zooplankton taxa: Rotifera (Synchaeta baltica), Copepoda (Eurytemora affinis) and Cladocera (Daphnia magna) and as a comparison a zooplankton free control. We used false bottom chambers separating the cyanobacterium and zooplankton and were thereby able to prevent direct grazing. Overall, N. spumigena toxin levels (nodularin expressed as microcystin equivalents) were significantly lower when exposed to the different zooplankton compared to the zooplankton free control, whereas no effects could be detected on N. spumigena growth and biomass. Although we did not test the underlying mechanism, these findings suggest that the presence of zooplankton reduce toxin production in N. spumigena, independent of growth. Therefore, toxin production in N. spumigena should not be considered an induced defence mechanism against zooplankton, at least not on a short-term basis.

The Collagen-binding Integrin α2β1 Is a Novel Interaction Partner of the Trimeresurus flavoviridis Venom Protein Flavocetin-A

Many snake venoms are known for their antithrombotic activity. They contain components that specifically target different platelet-activating receptors such as the collagen-binding integrin α2β1 and the von Willebrand factor receptor GPIb. In a search for an α2β1 integrin-blocking component from the venom of the habu snake (Trimeresurus flavoviridis), we employed two independent purification protocols. First, we used the integrin α2A domain, a major collagen-binding domain, as bait for affinity purification of an α2β1 integrin-binding toxin from the crude venom. Second, in parallel, we used classical protein separation protocols and tested for α2β1 integrin-inhibiting capabilities by ELISA. Using both approaches, we identified flavocetin-A as an inhibitor of α2β1 integrin. Hitherto, flavocetin-A has been reported as a GPIb inhibitor. However, flavocetin-A inhibited collagen-induced platelet aggregation even after GPIb was blocked with other inhibitors. Moreover, flavocetin-A antagonized α2β1 integrin-mediated adhesion and migration of HT1080 human fibrosarcoma cells, which lack any GPIb, on collagen. Protein chemical analyses proved that flavocetin-A binds to α2β1 integrin and its α2A domain with high affinity and in a cooperative manner, which most likely is due to its quaternary structure. Kinetic measurements confirmed the formation of a strong complex between integrin and flavocetin-A, which dissociates very slowly. This study proves that flavocetin-A, which has long been known as a GPIb inhibitor, efficiently targets α2β1 integrin and thus blocks collagen-induced platelet activation. Moreover, our findings suggest that the separation of GPIb- and α2β1 integrin-blocking members within the C-type lectin-related protein family is less strict than previously assumed.

Abstract P5-04-02: DYRK2 regulates breast cancer invasion via Snail/E-cadherin pathway

Abstract Introduction: Epithelial-Mesenchymal Transition (EMT) is characterized by the loss of cellular adhesion molecule E-cadherin, and plays a fundamental role during early steps of breast cancer invasion. An important regulator of E-cadherin expression is Snail, a zinc finger transcriptional repressor. Snail is posphorylated by GSK3β and then degraded by βTrCP mediated ubiquitination. Here we found another kinase, DYRK2, regulates the stability of Snail. Knockdown of DYRK2 promoted the EMT and cancer invasion both in vitro and in vivo experiments. Methods: Cell lines: MCF-7 cells were transfected with pSuper vector (pSuper control) and pSuper shRNA DYRK2 (shRNA-DYRK2) with G418 to isolate stable cell lines. Immunoblotting: Expression of pertinent molecular markers was determined by western blotting. RT-PCR: RNA was extracted using TRIsure and 500 ng of total RNA was amplified using Primer Script One Step RT-PCR Kit Ver.2. Invasion assay: Various cancer cell lines were seeded on the top of the upper chamber with serum free medium while the bottom chambers were filled with medium containing 10% FBS. In vivo metastasis assay: Cells in PBS were injected into the left ventricle of 7-week-old female nude mice. Metastases to distant organs were confirmed by IVIS2000. Immunohistochemistry: We acquired paraffin-embedded tissue sections from primary breast tumor cores and from Jikei University of Medicine. Immunohistochemistry for DYRK2 was performed. Results: In MCF-7 cells, knockdown of DYRK2 increased Snail in the protein level but not in mRNA level. Upon DYRK2 knockdown, MG132 treatment had no effect on additional increase in Snail. DYRK2 knockdown decreased Snail ubiquitination. Stable DYRK2 depletion led to Snail accumulation and E-cadherin abrogation. Fibroblast marker, Vimentin, emerged in DYRK2 depleted cells. For further analysis, we carried out invasion assays. The invasion potential in DYRK2-depleted cells was substantially higher than that in control cells. In xenograft model, we used nude mice received intracardial injections of pSuper control or shRNA-DYRK2 cells. 6 weeks after injections, a significant increase in bone and lung metastasis was observed in shRNA-DYRK2 group. The patients with tumors expressed low DYRK2 showed significantly poor prognosis. Conclusion: In breast cancer cells, Snail is phosphorylated by DYRK2 and then acquires the ability to be ubiquitinated. In the absence of DYRK2, Snail is unable to be degraded by ubiquitin-proteasome machinery. Accumulation of Snail promotes EMT and cancer invasion, so low expression of DYRK2 leads to poor prognosis in breast cancer. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-04-02.

Endogenous Expression of Matriptase in Neural Progenitor Cells Promotes Cell Migration and Neuron Differentiation

Recent studies show that type II transmembrane serine proteases play important roles in diverse cellular activities and pathological processes. Their expression and functions in the central nervous system, however, are largely unexplored. In this study, we show that the expression of one such member, matriptase (MTP), was cell type-restricted and primarily expressed in neural progenitor (NP) cells and neurons. Blocking MTP expression or MTP activity prevented NP cell traverse of reconstituted basement membrane, whereas overexpression of MTP promoted it. The NP cell mobilization induced by either vascular endothelial growth factor or hepatocyte growth factor was also impaired by knocking down MTP expression. MTP acts upstream of matrix metalloproteinase 2 in promoting NP cell mobility. In embryonic stem cell differentiation to neural cells, MTP knockdown had no effect on entry of embryonic stem cells into the neural lineage. High MTP expression or activity, however, shifts the population dynamics from NP cells toward neurons to favor neuronal differentiation. This is the first report to demonstrate the direct involvement of type II transmembrane serine protease in NP cell function.

Root system architecture of Kosteletzkya pentacarpos (Malvaceae) and belowground environmental influences on root and aerial growth dynamics

Root growth and architecture of Kosteletzkya pentacarpos and its response to nutrients and soil texture were studied to facilitate domestication of this plant as a biofuel crop (seeds for oil, stems for ethanol). Because it is salt tolerant, it does not compete with food crops for land. Four soil treatments in the bottom chambers of two-chambered growing units (three nutrient levels in sandy loam and saline, dredged material) were used to test substrate influences on root structure and aerial growth in a greenhouse study. Simultaneously, underground reserves were determined by collecting aerial biomass of dark-grown plants. Root cores (15 × 50 cm) were taken to determine root architecture of 2-year-old field-grown plants. High nutrient availability increased the coarse root biomass (≥2 mm diameter) and increased capsule production. Plants grown in dredged sediment had no substantial growth differences from the controls. Underground reserves were significant. Field cores demonstrated that roots extended more than 50 cm with most of the coarse roots in the upper 20 cm and the coarse to fine root ratio decreasing with depth. Fine root surface area, measured using image-analysis software, was substantially greater than many other crops, as was root mass density. Root architecture of K. pentacarpos and its responses to various nutrient levels and soil types demonstrate that it is a promising species for further development as a crop on coastal saline land including dredged material sites. Its perennial taproot system stores carbon and will perform buffer functions between upland and wetlands as sea level rises.

Studying chemical exchange across the water-bed interface in Golubaya Bay, the Black Sea

The results of first application of automated bottom station for studying chemical exchange across the water-bed interface (IO RAS lander) were obtained for the case of sediments in the northwestern Black Sea near Gelendzhik (Golubaya Bay). The lander is equipped with bottom chambers, sensors of environmental characteristics, and samplers, allowing fluxes of chemical elements through the water-bed interface to be determined directly. Bottom sediments were represented by organogenous silts containing hydrogen sulfide. The high activity of diagenetic processes resulted in a higher consumption of O2 by sediments (the flux from the bottom water was 130 mM/(m2/day), high fluxes of biogenic elements (P, Si,) and metals (Mn, Fe). At the same time, fluxes across the water-bed interface were evaluated based on the difference between concentrations of these elements in the near-bed and silt water (Fick’s law). The obtained data demonstrate the priority of direct measurements of fluxes (lander) over the calculation method. The first application of the lander suggests the need for methodological improvements both of engineering character and in chemical-analytical support.

Abstract 5507: The development and evaluation of a model for assessing convective fluid flow through multicell layers in vitro

Abstract Introduction: Elevated interstitial fluid pressure (IFP) is a characteristic feature of many solid tumours. One consequence of elevated IFP is that the normal process of convective fluid flow through tissues is impeded, and this is now recognised as a major barrier to drug uptake. Therapeutic approaches designed to reduce tumour IFP with the aim of restoring convective fluid flow thereby enhancing the delivery of partner therapeutics, are currently of considerable interest. To date, studies of intratumoural IFP have almost exclusively used in vivo models; the aim of this study was to develop an in vitro model that could be used to measure convective fluid flow. Methods: The standard approach to analysing drug penetration through multicell layers involves culturing cells on transwell membranes which are then inserted into one well of a 24 well plate. The level of medium is the same in both top and bottom chambers, so there is no pressure gradient across the membrane. In a modification of this model, a graduated tube is attached to the top chamber of the transwell; the level of medium in the top chamber can be systematically raised above that in the bottom chamber thereby creating a pressure gradient across the membrane. Convective flow is determined by measuring the weight of medium in the bottom chamber as a function of time, expressed as ml/min. DLD-1 human colorectal cells were grown on the transwell membrane to various thicknesses and convective flow was determined using this model. Results: Collagen coated membranes with a pore size of 3 μm provided a consistent flow rate of 5.5 ml/min when the hydrostatic pressure gradient applied across the membrane was 28.8 mmHg (13mls of medium in the graduated tube). DLD-1 cells seeded 1 × 105 cells per well were cultured at 37oC for up to 6 days with daily changes in medium. Histological analysis allowed the thickness of the multicell layer to be determined using a graduated eyepiece calibrated with a stage micrometer. The thickness of the multicell layer increased from 6.17 ± 2.12 μm to 19.62 ± 4.21 μm on days 1 and 5 of culture respectively. With a pressure gradient of 28.8 mmHg, convective flow rates ranged from 0.192 ml/min to 0.09 ml/min on days 1 to 4 of culture respectively; beyond day 4, the convective flow rate was less than 0.001 ml/min. Conclusions: A novel model for measuring the convective flow of fluid across multicell layers in vitro has been developed. Initial validation of this model has demonstrated that as the thickness of the multicell layer increases, convective flow decreases. In the case of DLD-1 cells, multicell layers of approximately 20 μm completely prevented convective flow. Further characterisation of this model is required but these initial results suggest it could be used to assess therapeutic strategies designed to modulate the tumour microenvironment with the aim of restoring or modifying convective fluid flow. Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5507.

New Approach to Evaluate Pollutant Removal by Storm-Water Treatment Devices

A methodology was developed to monitor and evaluate the removal of solids and associated constituents by a nutrient separating baffle box (NSBB) storm-water treatment device treating runoff from a 4.3 ha (10.6 acre) residential watershed discharging into the Indian River Lagoon, Florida. The NSBB was monitored over a 359-day time period using autosamplers to quantify water column removal during runoff events, and by quantifying and analyzing solids that accumulated within the NSBB. Flow composited influent and effluent samples were collected to represent water column performance. Event mean concentration (EMC) reduction was moderate (mean: 17%) and variable (range: −39 to 68%) for suspended solids, and negative for nitrogen, phosphorus, fecal coliforms chromium, and copper. The mass of solids that accumulated in bottom chambers and in a strainer screen was quantified and analyzed for nitrogen, phosphorus, heavy metals, and polycyclic aromatic hydrocarbons. A quantitative evaluative framework was devised to estimate the total pollutant mass removal by NSBB, which consisted of the summation of the separately calculated mass removals for water column, bottom chamber material, and strainer screen material. The water column accounted for only 4% of total solids that accumulated in the NSBB, which was equally divided between bottom chamber and strainer screen. Removal of nitrogen, phosphorus, and metals could be accounted for only by considering mass accumulations. Results suggest that overall assessment of pollutant removal by NSBB must be cognizant of the materials not captured by typical autosamplers: larger size sediment particles, large floating and suspended matter, and the pollutants associated with these materials. Using water column EMCs as the sole measure of performance significantly underestimated loading reduction of storm-water constituents by the NSBB. The monitoring and evaluative methodology applied to the NSBB may be applicable to load reduction evaluations for other storm-water treatment devices with a similar function.

A new streaming potential chamber for zeta potential measurements of particulates

A novel streaming potential measurement device has been validated by determining the average electrokinetic (zeta) potential of densely packed particulate such as human erythrocytes and ground bovine cortical bone. The new streaming potential device used in this study is easy to construct in the laboratory, designed to allow dense packing of particles, and determines zeta potentials for a broad range of particle sizes. The streaming potential device consists of four Plexiglas parts: (i) an upper and (ii) a lower chamber, which act as reservoirs for fluid; (iii) a midchamber which connects the upper and lower chambers and holds the sample holder, and (iv) a sample holder. Pressurization of fluid in the top chamber generates a pressure gradient that induces movement of fluid through the stationary sample and into the bottom chamber. Pressure induced flow through the interconnected pores of the densely packed particulate generates a potential difference across the sample that is measured using electrodes housed in the top and bottom chambers. The measured potential difference is then converted to zeta potentials. The advantage of this chamber is its ability to handle densely packed particulates exhibiting a broad distribution of sizes. Dense packing of particulate is achieved by compacting samples at the bottom of the sample holder under centrifugal forces before the device is assembled. This approach allowed us to determine average zeta potentials of densely packed particulate made of soft and hard materials.