1,308 research outputs found

    Carbon dioxide flux and net primary production of a boreal treed bog: Responses to warming and water-table-lowering simulations of climate change

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    Midlatitude treed bogs represent significant carbon (C) stocks and are highly sensitive to global climate change. In a dry continental treed bog, we compared three sites: control, recent (1–3 years; experimental) and older drained (10–13 years), with water levels at 38, 74 and 120 cm below the surface, respectively. At each site we measured carbon dioxide (CO2) fluxes and estimated tree root respiration (Rr; across hummock–hollow microtopography of the forest floor) and net primary production (NPP) of trees during the growing seasons (May to October) of 2011–2013. The CO2–C balance was calculated by adding the net CO2 exchange of the forest floor (NEff-Rr) to the NPP of the trees. From cooler and wetter 2011 to the driest and the warmest 2013, the control site was a CO2–C sink of 92, 70 and 76 g m−2, the experimental site was a CO2–C source of 14, 57 and 135 g m−2, and the drained site was a progressively smaller source of 26, 23 and 13 g CO2–C m−2. The short-term drainage at the experimental site resulted in small changes in vegetation coverage and large net CO2 emissions at the microforms. In contrast, the longer-term drainage and deeper water level at the drained site resulted in the replacement of mosses with vascular plants (shrubs) on the hummocks and lichen in the hollows leading to the highest CO2 uptake at the drained hummocks and significant losses in the hollows. The tree NPP (including above- and below-ground growth and litter fall) in 2011 and 2012 was significantly higher at the drained site (92 and 83 g C m−2) than at the experimental (58 and 55 g C m−2) and control (52 and 46 g C m−2) sites. We also quantified the impact of climatic warming at all water table treatments by equipping additional plots with open-top chambers (OTCs) that caused a passive warming on average of ~ 1 °C and differential air warming of ~ 6 °C at midday full sun over the study years. Warming significantly enhanced shrub growth and the CO2 sink function of the drained hummocks (exceeding the cumulative respiration losses in hollows induced by the lowered water level × warming). There was an interaction of water level with warming across hummocks that resulted in the largest net CO2 uptake at the warmed drained hummocks. Thus in 2013, the warming treatment enhanced the sink function of the control site by 13 g m−2, reduced the source function of the experimental by 10 g m−2 and significantly enhanced the sink function of the drained site by 73 g m−2. Therefore, drying and warming in continental bogs is expected to initially accelerate CO2–C losses via ecosystem respiration, but persistent drought and warming is expected to restore the peatland's original CO2–C sink function as a result of the shifts in vegetation composition and productivity between the microforms and increased NPP of trees over time

    Responses of carbon dioxide flux and plant biomass to water table drawdown in a treed peatland in northern Alberta: a climate change perspective

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    Northern peatland ecosystems represent large carbon (C) stocks that are susceptible to changes such as accelerated mineralization due to water table lowering expected under a climate change scenario. During the growing seasons (1 May to 31 October) of 2011 and 2012 we monitored CO2 fluxes and plant biomass along a microtopographic gradient (hummocks-hollows) in an undisturbed dry continental boreal treed bog (control) and a nearby site that was drained (drained) in 2001. Ten years of drainage in the bog significantly increased coverage of shrubs at hummocks and lichens at hollows. Considering measured hummock coverage and including tree incremental growth, we estimate that the control site was a sink of −92 in 2011 and −70 g C m−2 in 2012, while the drained site was a source of 27 and 23 g C m−2 over the same years. We infer that, drainage-induced changes in vegetation growth led to increased biomass to counteract a portion of soil carbon losses. These results suggest that spatial variability (microtopography) and changes in vegetation community in boreal peatlands will affect how these ecosystems respond to lowered water table potentially induced by climate chang

    Gambaran Kualitas Hidup Pasien Ppok Stabil di Poli Paru RSUD Arifin Achmad Provinsi Riau dengan Menggunakan Kuesioner Sgrq

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    Chronic Obstructive Pulmonary Disease (COPD) is one of disease that have high morbidity and mortality, even in developingor developed country. One of negative effect of COPD is becoming low in quality of patients' life because this disease has a chronic and irreversible characters. This research was conducted to know about quality of COPD patients' life at Poli Paru RSUD Arifin Ahmad of Riau Province, included about patients' characteristic based on age, sex, occupation, education level, smoking status, and diagnosis level of COPD patients. This research was conducted at Poli Paru RSUD Arifin Ahmad of Riau Province, and the design of this research used cross sectional descriptive design. The sample of this research was COPD patients that has fully achieved of inclusion and exclusion criteria by using collecting consecutive sampling technique with 64 respondents. The data was collected from SGRQ questionnaire. Based on the analyzing of data, there were found that majority of COPD patients contributed onsex (male) (80,28%), elderly (64,78%), primary educational level (36,61%), smoker (61,97%), retired (25,35%), and new COPD diagnostic <3 years (60.56%). In general, the quality of COPD patients' life is not good which showed (61,97%)

    Gambaran Faal Paru Pada Pasien Asma Yang Melakukan Senam Asma Dengan Yang Tidak Melakukan Senam Asma

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    Asthma is chronic inflammation disorder of respiratory tract that cause trial episode of symptoms like wheezing, breathlessness, feel heavy in chest, cough especially in the night or early morning that reversible with or without therapy. Spirometry is used in clinical examination to diagnose and evaluation patient with asthma. Asthma gymnastic is one of recommendation exercise therapy to help the process of rehabilitation in asthma patient. This study was cross sectional descriptive that used total sampling method which explained overview lung function of asthma patient that followed asthma gymnastic and not followed asthma gymnastic. In this study, total sampling was 62 patient which 31 asthma patient that followed asthma gymnastic and 31 not followed asthma gymnastic. The result showed asthma patient that followed asthma gymnastic were in the age group 41-50 years old consist of 12 patient (38,7%), most commonly happened in female consist of 24 patient (77,4%), most common not had comorbidities consist of 18 patient (58%), most common patient had family history of asthma consist of 19 patient (61,3%), the lung function was obstructive consist of 17 patient (54.9%), the level of asthma was intermittent consist of 12 patient (38.7%), assessment of asthma control was controlled consist of 14 patient (45.1%) the length of time following the most gymnastic was asthma ≥3 month 19 patient (61,3%). In asthma patient that was not followed asthma gymnastic were in the age group 41-50 years old consist of 13 patient (42%), most commonly happened in female consist of 27 patient (81,7%), most common had comorbidities consist of 18 patient (58%), most common patient not had family history of asthma consist of 16 patient (51,6%), the lung function was restrictive consist of 20 patient (64.5%), the level of asthma was severe persistent consist of 12 patient (38.7%) and assessment of asthma control was controlled consist of 18 patient (58.1%)

    Sintesis Nanoserat Poli(vinil Alkohol) Dalam Bentuk Lembaran Dengan Pemintal Elektrik Multi Nozel Dan Kolektor Drum

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    Electrospinning system with single needle and planar collector has the disadvantage of a low productivity. To overcome this problem drum collector and multi-nozzle system were employed. The multi-nozzle system was used to improve the production rate, while the drum collector was used for maintaining the uniformity of the size. The purposes of this study were to examine the influence of electric field in the electrospinning process and to control the morphology of the obtained poly(vinyl alcohol)/PVA nanofibers by changing the solution flow rate. The obtained results were: (1) PVA nanofibers membrane have been successfully produced stacked on the drum collector, (2) distortion of the electric field at the tip of the needle was occurred, which results in inhomogeneous thickness of the stacked nanofibers, and (3) the morphology of the obtained nanofibers at the flow rates of 0.4 and 0.6 ml/hour have many beads while at 0.8 ml/hour the number of beads decreased

    Virtual milk for modelling and simulation of dairy processes

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    AbstractThe modeling of dairy processing using a generic process simulator suffers from shortcomings, given that many simulators do not contain milk components in their component libraries. Recently, pseudo-milk components for a commercial process simulator were proposed for simulation and the current work extends this pseudo-milk concept by studying the effect of both total milk solids and temperature on key physical properties such as thermal conductivity, density, viscosity, and heat capacity. This paper also uses expanded fluid and power law models to predict milk viscosity over the temperature range from 4 to 75°C and develops a succinct regressed model for heat capacity as a function of temperature and fat composition. The pseudo-milk was validated by comparing the simulated and actual values of the physical properties of milk. The milk thermal conductivity, density, viscosity, and heat capacity showed differences of less than 2, 4, 3, and 1.5%, respectively, between the simulated results and actual values. This work extends the capabilities of the previously proposed pseudo-milk and of a process simulator to model dairy processes, processing different types of milk (e.g., whole milk, skim milk, and concentrated milk) with different intrinsic compositions, and to predict correct material and energy balances for dairy processes

    Radiologic feeding gastrostomy placement: experience in 23 patients

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    Objective: To evaluate the safety, efficacy and complications of percutaneous gastrostomy catheter placementunder flouro guidance for long-term enteral feeding.MATERIALS AND Methods: Between April 1998 to May 2002, 23 patients who had percutaneous gastrostomy catheter placement were retrospectively reviewed. Clinical indications for catheter placement included patients with neurologic disease, head and neck malignancy, and pulmonary disease patients. Placement of 12 - 14 Fr gastrostomy catheter was then accomplished with the Seldinger technique. The technical success, procedural complications were recorded.Results: Twenty seven procedures, including revisions, were performed. The success rate for catheter placement was 100%. Revision was necessary in 7 (30%) instances in 7 patients. There was one (3.8%) major and 4 (14.8%) minor complications.CONCLUSION: Fluoroscopically directed percutaneous placement of gastrostomy catheters is a safe and effective procedure

    Perancangan Antarmuka Sistem Pakar Penyakit Padi Berbasis Web

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    Antarmuka merupakan salah satu bagian dari perangkat lunak yang berhubungan langsung dengan pengguna. Pengguna berinteraksi dengan sistem perangkat lunak melalui antarmuka pengguna. Penelitan terdahulu pada sistem pakar penyakit padi hanya terbatas pada pengujian apakah sistem pakar dapat berjalan tanpa memperhatikan aspek antarmuka pengguna. Tujuan dari penelitian ini adalah merancang antarmuka pengguna (user interface) pada sistem pakar penyakit padi dengan berbasis web. Tahapan-tahapan pada penelitian ini adalah melakukan analisis calon pengguna dan pihak terkait yang dapat menjadi kandidat pengguna, pemilihan platform pengembangan yaitu berbasis web, analisis user environment atau lingkungan pengguna yang berkaitan dengan basis web, perancangan struktur menu, perancangan antarmuka, dan evaluasi. Hasil rancangan dievaluasi dengan menggunakan model pendekatan evaluasi heuristik penggunaan (USAbility heuristics) yang diperkenalkan oleh Jacob Nielson untuk mengetahui kekurangan dan saran rancangan antarmuka sistem pakar. Hasil dari evaluasi heuristik penggunaan adalah penggunaan kata berbahasa Inggris seperti username, password, FAQ serta penggunaan kata tidak baku yaitu diagnosa pada aspek kesesuaian antara sistem dan dunia nyata. Kurangnya ikon pada menu dan perbedaan tombol dan teks yang kurang jelas pada aspek memahami lebih baik daripada mengingat. Pesan kesalahan yang muncul kurang detai
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