Rocky intertidal filter feeders couple benthic and pelagic systems by consuming particles in the water column and transferring energy and nutrients to sediments and benthic predators. Less is known ...about their role as links between terrestrial and marine systems. I explored this link using a dual stable isotope approach to discern the diets and trophic position of 4 common sympatric rocky intertidal filter feeders (Mytilus californianus,Balanus glandula,Semibalanus cariosus, Pollicipes polymerus) living near river mouths in the Pacific Northwest (USA). Freshwater particulate organic matter (POM) was assimilated by all filter feeders, though at relatively low levels (5 to 41%). Intertidal macroalgae and seagrass also contributed to filter feeder diets, but the primary resource base was kelp in both summer and winter, accounting for 11 to 88% in filter feeder diets, depending on species and season. Although these species shared a common resource base, they occupied distinct trophic positions. Natural and logging-induced increases in riverine inputs were related to higher trophic position for all species, indicating that riverine carbon may enter the rocky intertidal food web through the microbial loop. I show that filter feeder trophic positions were higher in winter when river discharge is highest, near river mouths (in winter) where river-borne inputs are highest, and downstream of more heavily logged watersheds where river loads of dissolved organic carbon are highest. Rocky intertidal filter feeders do couple land and sea, further emphasizing the need to manage these ecosystems jointly.
Farmer profit can be increased and air quality improved
Although intentional use of fires to transform land has decreased globally (
1
,
2
), particularly among highly capitalized countries through ...regulatory and market-oriented approaches and moral suasion, regulatory strategies have been less effective in southern and eastern Asia (see table S21). Some densely populated agricultural regions in China and India buck the global trend, showing increases in agricultural fires (
2
). This is particularly true in northwestern India, where rice residue burning makes a substantial contribution to air pollution and short-lived climate pollutants (
3
,
4
). Regulations are in place to reduce agricultural fires, but burning continues because of uncertainty regarding policy implementation and regarding access and returns to alternative technologies. With the field burning season soon upon us, we synthesize emerging evidence on alternatives to burning, clarify the business case for alternative practices, identify remaining uncertainties, and discuss approaches to increase their widespread adoption. Often, there are difficult trade-offs between environmental improvement and profitable economic opportunities. The case of crop residue management in northwestern India does not appear to fit this pattern and provides lessons that may be useful elsewhere.
This paper presents a two dimensional force sensor fabricated on PDMS nanocomposite, with patterned carbon nanotubes (CNTs) acting as a force sensing unit. A novel fabrication method is composed of ...inkjet printing of CNTs onto polyethylene terephthalate (PET) and subsequent transfer of the CNT patterns to PDMS, resulting in a CNT-elastomer nanocomposite that is flexible and conductive. This approach allows patterning of a large-area conductive carbon nanotube pattern on PDMS. The achieved sheet resistance of the transferred patterns on PDMS was 1.2kΩ/□ when printed 35 times, using an office inkjet printer. The fabricated sensor changes its resistance when force is applied perpendicularly to the sensor. A two dimensional force sensor, working on the principle of compression-induced deformation was fabricated and characterized with achieved resolution of four sensing cells per cm2. Additionally, we demonstrate a two dimensional flexible force sensor capable of creating a pressure map of the applied force. Together with inkjet printing, this pattern transfer process represents a highly effective patterning technique for embedding carbon nanotubes in PDMS.
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•A transfer printing technique has been developed to pattern embedded carbon nanotubes onto PDMS.•Patterns show good uniformity, forming an embedded CNT network.•A highly flexible two dimensional force sensor has been demonstrated, showing the pressure map applied.
Microelectrodes for detection of chemicals present several advantages over conventional sized electrodes. However, rapid and low-cost fabrication of microelectrodes is challenging due to high ...complexity of patterning equipment. We present the development of a low-cost, customizable inkjet printer for printing nanomaterials including carbon nanotubes for the fabrication of microelectrodes. The achieved spatial resolution of the inkjet printer is less than 20 µm, which is comparable to advanced commercially available inkjet printers, with the advantage of being low-cost and easily replicated.
This paper proposes a simple and rapid fabrication of a glucose sensor based on inkjet printing method. A commercially available inkjet printer is used to print carbon nanotubes and polyaniline ...nanowires for patterning low sheet resistance electrodes and a chemiresistive glucose sensing area, respectively. Enzyme glucose oxidase, in conjunction with platinum nanoparticles were also incorporated into the chemiresistive sensor to generate a two-step catalytic process: in the first step, glucose is catalyzed by the oxidase to produce hydrogen peroxide as a byproduct, and in the second step, platinum nanoparticles catalyze hydrogen peroxide to produce hydroxide ions which causes a local pH change near the site of reaction. Since the conductivity of polyaniline is known to be pH-responsive, the polyaniline layer serves as a chemiresistive sensor to detect the H
2
O
2
concentration which subsequently leads to the quantification of the glucose concentration. The developed inkjet-printed glucose sensor was able to achieve a detection limit of 2 mM and a good linear relationship between current measurements and glucose concentration was obtained. The results indicate that the proposed method to print a simple, rapid, and disposable glucose sensing device can lead to the development of an on-demand printable point-of-care diagnostic kit for glucose measurement.
This work reports an inkjet printing technique for patterning a conducting polymer nanowire network on a flexible film for applications in chemical sensing. The novelty of this work is in the ...patterning capability of polymer nanowires to form a conducting path. Polyaniline nanowires were chemically synthesized in an aqueous solution and a surfactant was added to lower the surface tension which enabled the printing of the nanowires using a commercially available inkjet printer. The nanowire network-based patterns were printed on a flexible transparency film, and its morphology characterization, patterning ability as well as the electrical properties were investigated. Finally, as a proof-of-concept, a fully-printed chemical sensors were developed by using the proposed printing technique on flexible films. Two types of sensors were fabricated: a pH sensor and a hydrogen peroxide sensor. The results demonstrate that the developed sensors can be utilized as a low cost, disposable, and easily printable chemical sensors. The proposed technology may find applications in the development of a simple print-and-use biochemical sensing kit for potential use in point-of-care diagnostics.
Advances in several engineering fields have led to a trend toward miniaturization and portability of wearable biosensing devices, which used to be confined to large tools and clinical settings. ...Various systems to continuously measure electrophysiological activity through electrical and optical methods are one category of such devices. Being wearable and intended for prolonged use, the amount of noise introduced on sensors by movement remains a challenge and requires further optimization. User movement causes motion artifacts that alter the overall quality of the signals obtained, hence corrupting the resulting measurements. This paper introduces a fully wearable optical biosensing system to continuously measure pulse oximetry and heart rate, utilizing a reflectance-based probe. Furthermore, a novel data-dependent motion artifact tailoring algorithm is implemented to eliminate noisy data due to the motion artifact and measure oxygenation level with high accuracy in real time. By taking advantages of current wireless transmission and signal processing technologies, the developed wearable photoplethysmography device successfully captures the measured signals and sends them wirelessly to a mobile device for signal processing in real time. After applying motion artifact tailoring, evaluating accuracy with a continuous clinical device, the blood oxygenation measurements obtained from our system yielded an accuracy of at least 98%, when compared to a range of 93.6%-96.7% observed before from the same initial data. Additionally, heart rate accuracy above 97% was achieved. Motion artifact tailoring and removal in real time, continuous systems will allow wearable devices to be truly wearable and a reliable electrophysiological monitoring and diagnostics tool for everyday use.
This paper presents a fully inkjet-printed electrochemical sensor on paper which consists of carbon nanotube-printed working, reference, and counter electrodes. The proposed technique aims at ...low-cost and disposable paper-based electrochemical sensors. First, a carbon nanotube (CNT) ink was inkjet-printed directly on paper, forming a conductive network. Additionally, a hydrophobic barrier was patterned on paper to limit the absorption of liquid to the designed area. The inkjet printing method allows for rapid patterning of electrodes on paper, resulting in a simple and effective electrochemical sensor. The sheet resistance of the CNT-printed paper was as low as 1 kΩ/◻ after 33 prints. A potential step voltammetry method was applied to determine the concentration of the analytes, iron ion (Fe2+) and dopamine (DA), with linear ranges of 10 μM-200 μM and 10 μM-100 μM, respectively. The reported approach for a fully inkjet-printed electrochemical sensor is easy and cheap, and it has a potential for simple and rapid paper-based point-of-care diagnostics.
Bilateral adrenal metastases may cause adrenal insufficiency (AI) but it is unclear if screening for AI in patients with bilateral adrenal metastases is justified, despite the potential for adrenal ...crises.
A search using PubMed/Medline, ScienceDirect and Cochrane Reviews was performed to collect all original research articles and all case reports from the past 50 years that describe AI in bilateral adrenal metastases.
Twenty studies were included with 6 original research articles, 13 case reports and one case series. The quality was generally poor. The prevalence of AI was 3–8%. Of all cases of AI (n = 25) the mean pooled baseline cortisol was 318 ± 237 nmol/L and stimulated 423 ± 238 nmol/L. Hypotension was present in 69%, hyponatremia in 9% and hyperkalemia in 100%. Lung cancer was the cause in 35%, colorectal 20%, breast cancer 15% and lymphoma 10%. The size of the adrenal metastases was 5.5 ± 2.8 cm (left) and 5.5 ± 3.1 cm (right), respectively. There was no correlation between basal cortisol, stimulated cortisol concentration or ACTH with the size of adrenal metastases. The median time to death was 5.0 months (IQR 0.6–6.5). However, two cases were alive after 12–24 months.
The prevalence of AI in patients with bilateral adrenal metastases was low. Prognosis was very poor. Due to the low prevalence of AI, screening is likely only indicated in patients with symptoms and signs suggestive of hypocortisolism.
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