Neural Networks in the Analysis of Water-Soluble Sulfonylurea Herbicides Using an LC/MS

In this research, a hidden node pruning algorithm was developed for an artificial neural network (ANN) that automatically determined a more efficient size of the hidden layer, caused the ANN to resize itself, and then continued to train using a standard back-propagation algorithm. The hidden-node pruning algorithm was based on determining the number of significant eigenvalues present in the matrix of values produced by the hidden layer, starting with an excessive number of hidden nodes. Eight sulfonylurea herbicides were used as the target analytes in this study. The ability of an ANN to simplify the sample preparation needed for analysis using a liquid chromatograph/particle beam/mass spectrometer (LC/PB/MS) was evaluated. The results derived from this research demonstrated that ANNs allow the clean-up procedure to be simplified, while still obtaining reliable identification of the sulfonylurea herbicides in complex matrices such as soil. Specifically, this was accomplished by using retention times from the LC and MS when the herbicides were injected individually in pure forms combined with MS data obtained from extracted samples. This information was used by a trained neural network to identify sulfonylurea herbicides as both individual components and components in a mixture. Two different neural networks were created. One was trained with a single mass spectrum from each herbicide, resulting in an 8-training-sample network, and one was trained with five mass spectra of each herbicide, resulting in a 40-training-sample network. Both ANNs had 47 input nodes and eight output nodes. Starting with an excess of 20 hidden nodes, the networks resized themselves to contain 6 hidden nodes for the 8-training-sample network and 7 hidden nodes for the 40-training-sample network. An optimum sum-squared error (SSE) goal was determined to be 0.3 for the 8-training-sample network by using a statistical t-test . to establish the smallest SSE where the standard error of prediction was not significantly greater than the standard error of calibration. Results demonstrated that the 8-training-sample ANN performed just as well as the 40-training-sample ANN. When compared to the Hewlett-Packard probability-based matching (HP- PBM) library searching system, both neural networks out-performed the HP-PBM system in the identification of unknown mass spectra

City of Pompano Beach Proclamation

NSU 50th Anniversaryhttps://nsuworks.nova.edu/nsudigital_proclamations/1003/thumbnail.jp

Control of Initiation, Rate, and Routing of Spontaneous Capillary-Driven Flow of Liquid Droplets through Microfluidic Channels on SlipChip

This Article describes the use of capillary pressure to initiate and control the rate of spontaneous liquid–liquid flow through microfluidic channels. In contrast to flow driven by external pressure, flow driven by capillary pressure is dominated by interfacial phenomena and is exquisitely sensitive to the chemical composition and geometry of the fluids and channels. A stepwise change in capillary force was initiated on a hydrophobic SlipChip by slipping a shallow channel containing an aqueous droplet into contact with a slightly deeper channel filled with immiscible oil. This action induced spontaneous flow of the droplet into the deeper channel. A model predicting the rate of spontaneous flow was developed on the basis of the balance of net capillary force with viscous flow resistance, using as inputs the liquid–liquid surface tension, the advancing and receding contact angles at the three-phase aqueous–oil–surface contact line, and the geometry of the devices. The impact of contact angle hysteresis, the presence or absence of a lubricating oil layer, and adsorption of surface-active compounds at liquid–liquid or liquid–solid interfaces were quantified. Two regimes of flow spanning a 104-fold range of flow rates were obtained and modeled quantitatively, with faster (mm/s) flow obtained when oil could escape through connected channels as it was displaced by flowing aqueous solution, and slower (micrometer/s) flow obtained when oil escape was mostly restricted to a micrometer-scale gap between the plates of the SlipChip (“dead-end flow”). Rupture of the lubricating oil layer (reminiscent of a Cassie–Wenzel transition) was proposed as a cause of discrepancy between the model and the experiment. Both dilute salt solutions and complex biological solutions such as human blood plasma could be flowed using this approach. We anticipate that flow driven by capillary pressure will be useful for the design and operation of flow in microfluidic applications that do not require external power, valves, or pumps, including on SlipChip and other droplet- or plug-based microfluidic devices. In addition, this approach may be used as a sensitive method of evaluating interfacial tension, contact angles, and wetting phenomena on chip

GAMBARAN INTENSITAS PENCAHAYAAN PADA PENJAHIT DI KOMPLEKS GEDUNG PRESIDENT PASAR 45 KOTA MANADO

Latar belakang: Berdasarkan penelitian sebelumnya yang dilakukan oleh Agustin Puryani Wulandari, (2010) pengaruh intensitas cahaya terhadap aktivitas kerja bagian produksi di PT. Indofood Cbp Sukses Makmur Divisi Noodle Cabang Semarang. Penelitian ini menunjukan bahwa pengaruh intensitas cahaya pada proses kerja yang tidak sesuai dengan jenis pekerjaan akan mengakibatkan gangguan ketidaknyamanan pada aktivitas kerja. Pencahayaan adalah faktor lingkungan kerja yang termasuk dalam kelompok faktor risiko. Oleh karenanya sama seperti faktor lingkungan yang lain (seperti kadar debu yang banyak, intensitas bising yang tinggi, panas yang berlebihan, radiasi mengion ataupun radiasi yang tidak mengion), apabila intensitas pencahayaan tidak memadai (suram ataupun menyilaukan), maka dapat menyebabkan produktivitas tenaga kerja menurun ataupun menjadi rendah. Pencahayaan yang kurang baik dapat mengakibatkan pekerjaan menjadi lebih rumit dan sukar karena mengganggu penglihatan dari penjahit pakaian. Metode penelitian: Metode penelitian yang digunakan dalam penelitian ini adalah deskriptif.  Yaitu  memberikan gambaran secara jelas yang terbatas pada usaha mengungkapkan suatu masalah dan keadaan sebagaimana adanya sehingga hanya merupakan penyikapan suatu fakta dan data yang diperoleh digunakan sebagai bahan penulisan laporan. Dalam laporan ini, penulis memaparkan hasil peninjauan, pengamatan dan pengukuran tentang intensitas penerangan pada penjahit di kompleks Gedung President Pasar 45 Kota Manado. Populasi dari penelitian ini adalah semua penjahit di kompleks Gedung President Pasar 45 yang berjumlah 31 penjahit. Sampel  dari penelitian ini adalah semua populasi penjahit di kompleks Gedung President Pasar 45 yang berjumlah 31 penjahit. Intensitas pencahayaan ini di ukur menggunakan alat ukur pencahayaan (Lux meter) dengan satuan pengukuran 200 Lux. Hasil penelitian: Distribusi frekuensi gambaran intensitas pencahayaan terdapat 29 Orang (93,5%) pekerja dengan umur 15-49 tahundan 2 orang (6,5%) pekerja dengan umur ≥ 50 tahun, 16 orang (51,6%) pekerja laki-laki dan 15 (48,4%) pekerja perempuan, 25 orang (80,6%) pekerja berpendidikan terkahir SMA dan 6 Orang (19,4%) pekerja berpendidikan terakhir SMP, dan 21 Orang (67,7%) dengan masa kerja> 4 Tahun dan 10 Orang (32,3%) dengan masa kerja ≤ 4 Tahun. Dari Intensitas pencahayaan, terdapat 18 orang (58,1%) pekerja yang bekerja dengan memenuhi persyaratan Luks minimal untuk bekerja dan 13 Orang (41,9%). Kesimpulan: Berdasarkan hasil penelitian yang dilakukan dapat disimpulkan bahwa terdapat perbedaan intensitas pencahayaan pada penjahit di Kompleks Gedung President Pasar 45 Kota Manado yang dimana ada sejumlah 13 penjahit yang intensitas pencahayaannya tidak memenuhi syarat ( 4 years and 10 people (32.3%) with a working period ≤ 4 years. From the intensity of the lighting, there are 18 persons (58.1%) workers working with Luks are eligible to work on and at least 13 people (41.9%). Based on the results of research conducted can be concluded that there is a difference in the intensity of the lighting on the tailor in the complex Building President Market 45 Manado city in which there are a number of 13 seamstresses intensity pencahayaannya not qualified (200 < Luks) and 18 tailor who qualified pencahayaannya intensity ≥ 200 Luks. Keywords: Lighting Intensity

Crown Ether-Metal ‘Sandwiches’ As Linking Mechanisms in Assembled Nanoparticle Films

Crown ether ligands attached to monolayer-protected clusters (MPCs) were assembled as films and the linking mechanism between the crown ether–metal ion–crown ether bridges between nanoparticles was examined. Thicker films exhibited a red shift in the absorbance maximum for the surface plasmon band which was attributed to the increasing aggregation and cross linking within the film. Quantized double layer charging peaks suggest that film growth is selective toward a specific core size or exchange rate, either of which affect the number of potential linking ligands in the periphery of the MPCs. Multi-layer growth of films was only achieved with metal ions capable of coordinating within the cavity of the 15-crown-5 ether. Our exchange reaction parameters are in stark contrast to other types of MPC film assemblies

Toward Mechanistic Understanding of Nuclear Reprocessing Chemistries by Quantifying Lanthanide Solvent Extraction Kinetics via Microfluidics with Constant Interfacial Area and Rapid Mixing

The closing of the nuclear fuel cycle is an unsolved problem of great importance. Separating radionuclides produced in a nuclear reactor is useful both for the storage of nuclear waste and for recycling of nuclear fuel. These separations can be performed by designing appropriate chelation chemistries and liquid-liquid extraction schemes, such as in the TALSPEAK process (Trivalent Actinide-Lanthanide Separation by Phosphorus reagent Extraction from Aqueous Komplexes). However, there are no approved methods for the industrial scale reprocessing of civilian nuclear fuel in the United States. One bottleneck in the design of next-generation solvent extraction-based nuclear fuel reprocessing schemes is a lack of interfacial mass transfer rate constants obtained under well-controlled conditions for lanthanide and actinide ligand complexes; such rate constants are a prerequisite for mechanistic understanding of the extraction chemistries involved and are of great assistance in the design of new chemistries. In addition, rate constants obtained under conditions of known interfacial area have immediate, practical utility in models required for the scaling-up of laboratory-scale demonstrations to industrial-scale solutions. Existing experimental techniques for determining these rate constants suffer from two key drawbacks: either slow mixing or unknown interfacial area. The volume of waste produced by traditional methods is an additional, practical concern in experiments involving radioactive elements, both from disposal cost and experimenter safety standpoints. In this paper, we test a plug-based microfluidic system that uses flowing plugs (droplets) in microfluidic channels to determine absolute interfacial mass transfer rate constants under conditions of both rapid mixing and controlled interfacial area. We utilize this system to determine, for the first time, the rate constants for interfacial transfer of all lanthanides, minus promethium, plus yttrium, under TALSPEAK process conditions, as a first step toward testing the molecular mechanism of this separation process

Spatial localization of bacteria controls coagulation of human blood by ‘quorum acting'

Blood coagulation often accompanies bacterial infections and sepsis and is generally accepted as a consequence of immune responses. Though many bacterial species can directly activate individual coagulation factors, they have not been shown to directly initiate the coagulation cascade that precedes clot formation. Here we demonstrated, using microfluidics and surface patterning, that the spatial localization of bacteria substantially affects coagulation of human and mouse blood and plasma. Bacillus cereus and Bacillus anthracis, the anthrax-causing pathogen, directly initiated coagulation of blood in minutes when bacterial cells were clustered. Coagulation of human blood by B. anthracis required secreted zinc metalloprotease InhA1, which activated prothrombin and factor X directly (not via factor XII or tissue factor pathways). We refer to this mechanism as ‘quorum acting’ to distinguish it from quorum sensing—it does not require a change in gene expression, it can be rapid and it can be independent of bacterium-to-bacterium communication

Developing country consumers’ acceptance of biofortified foods: a synthesis

The success of biofortified staple crops depends on whether they are accepted and consumed by target populations. In the past 8 years, several studies were undertaken to understand consumers’ acceptance of foods made with biofortified staple crops. Consumer acceptance is measured in terms of their sensory evaluation and economic valuation of biofortified varieties vis-à-vis conventional ones. These studies apply expert sensory panel and hedonic trait analyses methods adopted from food sciences literature, as well as various preference elicitation methods (including experimental auctions, revealed choice experiments, and stated choice experiments) adopted from experimental economics literature. These studies also test the impact of various levers on consumers’ evaluation and valuation for biofortified foods. These levers include (i) nutrition information and the media through which such information is conveyed; (ii) the length and content of nutrition information; (iii) different branding options; (iv) the nature (national or international) of the branding/certification agency that is endorsing the biofortified staple food; and (v) the nature (national or international) of the agency that is delivering the biofortified staple food. This paper brings together evidence on consumer acceptance of biofortified crops on 5 crops across 7 countries in Africa, Asia and Latin America. The results of these studies are expected to aid in the development of biofortified crops that consumers like, as well as in the development of appropriate marketing and consumer awareness or information campaigns to encourage the switch in consumption from traditional staples to biofortified ones