321 research outputs found
Genetic algorithms for inventory constrained scheduling on a single machine
This paper focuses on Single machine scheduling subject to inventory constraints. Jobs add and remove items to and from, respectively, the inventory. Jobs that remove items cannot be processed if the required number of items is not available. We consider scheduling problems on a Single machine with regular objective functions Lmax ∑wjCj, ∑wjUj and ∑wjTj, and propose a genetic algorithm framework to tackle them. The focus is on discussion of different representations with respect to redundancy and corresponding decoding schemes. Moreover, we evaluate the different techniques by means of a computational study
Inventory constrained scheduling on a single machine
This paper studies inventory constraints in a machine scheduling environment. Jobs can add and remove items of different types to the inventory and from the inventory, respectively. Jobs removing items cannot be processed if the required amount of items is not available. We first have a look at general models and determine the computational status of these problems. Since it turns out that general models are strongly NP-hard except for makespan minimization on one machine we have a look at special cases in the following. We determine the computational complexity of all considered special cases for objection functions ∑Cj and Lmax and several special cases for objective functions ∑wjCj and ∑Uj
Allocating containers to ships with fixed departure times
We consider the problem of allocating containers to ships in which the size of container is 1 or 2, and each ship has its own capacity and fixed departure time. The fixed departure times implies the completion times of containers belonging to the same ship are identical. As objectives, Lmax, ∑wjCj, ∑wjUj and ∑Tj are considered. We verify the problems are closely related with the scheduling problem with eligibility constraint or the generalized assignment problem. The polynomial-time algorithms are developed for each problem, and moreover the more efficient algorithms are presented for the cases with ∑Cj and ∑Uj
Acupuncture Muscle Channel in the Subcutaneous Layer of Rat Skin
AbstractUsing a mixed-dye injection technique, we found a novel kind of muscle fiber with a lumen, established its precise location in the subcutaneous muscle layer along the acupuncture muscle of the bladder line, and determined its detailed ultrastructure. The channels with flowing liquid were a novel kind of muscle fibers with lumens and they were located in the subcutaneous muscle layer of rat. Their detection was realized by using chrome-hematoxylin and a mixture of fluorescent nanoparticles and commercial Pelikan ink. These acupuncture muscle channels were hidden among the neighboring skin skeletal muscle fibers and were barely distinguishable from them with light microscopes. Only with a transmission electron microscope were their characteristic features shown to be different from normal skin skeletal muscle. These features included undifferentiated muscle fibers that resembled immature myofibrils without Z-lines and reassembled telophase nuclei
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Characterization of Mammalian Selenoprotein O: A Redox-Active Mitochondrial Protein
Selenoproteins exhibit diverse biological functions, most of which are associated with redox control. However, the functions of approximately half of mammalian selenoproteins are not known. One such protein is Selenoprotein O (SelO), the largest mammalian selenoprotein with orthologs found in a wide range of organisms, including bacteria and yeast. Here, we report characterization of mammalian SelO. Expression of this protein could be verified in HEK 293T cells by metabolic labeling of cells with 75Se, and it was abolished when selenocysteine was replaced with serine. A CxxU motif was identified in the C-terminal region of SelO. This protein was reversibly oxidized in a time- and concentration-dependent manner in HEK 293T cells when cells were treated with hydrogen peroxide. This treatment led to the formation of a transient 88 kDa SelO-containing complex. The formation of this complex was enhanced by replacing the CxxU motif with SxxC, but abolished when it was replaced with SxxS, suggesting a redox interaction of SelO with another protein through its Sec residue. SelO was localized to mitochondria and expressed across mouse tissues. Its expression was little affected by selenium deficiency, suggesting it has a high priority for selenium supply. Taken together, these results show that SelO is a redox-active mitochondrial selenoprotein
The selenoproteome of \u3ci\u3eClostridium\u3c/i\u3e sp. OhILAs: Characterization of anaerobic bacterial selenoprotein methionine sulfoxide reductase A
Selenocysteine (Sec) is incorporated into proteins in response to UGA codons. This residue is frequently found at the catalytic sites of oxidoreductases. In this study, we characterized the selenoproteome of an anaerobic bacterium, Clostridium sp. (also known as Alkaliphilus oremlandii) OhILA, and identified 13 selenoprotein genes, five of which have not been previously described. One of the detected selenoproteins was methionine sulfoxide reductase A (MsrA), an antioxidant enzyme that repairs oxidatively damaged methionines in a stereospecific manner. To date, little is known about MsrA from anaerobes. We characterized this selenoprotein MsrA which had a single Sec residue at the catalytic site but no cysteine (Cys) residues in the protein sequence. Its SECIS (Sec insertion sequence) element did not resemble those in Escherichia coli. Although with low translational efficiency, the expression of the Clostridium selenoprotein msrA gene in E. coli could be demonstrated by 75Se metabolic labeling, immunoblot analyses, and enzyme assays, indicating that its SECIS element was recognized by the E. coli Sec insertion machinery. We found that the Sec-containing MsrA exhibited at least a 20-fold higher activity than its Cys mutant form, indicating a critical role of Sec in the catalytic activity of the enzyme. Furthermore, our data revealed that the Clostridium MsrA was inefficiently reducible by thioredoxin, which is a typical reducing agent for MsrA, suggesting the use of alternative electron donors in this anaerobic bacterium that directly act on the selenenic acid intermediate and do not require resolving Cys residues
The selenoproteome of \u3ci\u3eClostridium\u3c/i\u3e sp. OhILAs: Characterization of anaerobic bacterial selenoprotein methionine sulfoxide reductase A
Selenocysteine (Sec) is incorporated into proteins in response to UGA codons. This residue is frequently found at the catalytic sites of oxidoreductases. In this study, we characterized the selenoproteome of an anaerobic bacterium, Clostridium sp. (also known as Alkaliphilus oremlandii) OhILA, and identified 13 selenoprotein genes, five of which have not been previously described. One of the detected selenoproteins was methionine sulfoxide reductase A (MsrA), an antioxidant enzyme that repairs oxidatively damaged methionines in a stereospecific manner. To date, little is known about MsrA from anaerobes. We characterized this selenoprotein MsrA which had a single Sec residue at the catalytic site but no cysteine (Cys) residues in the protein sequence. Its SECIS (Sec insertion sequence) element did not resemble those in Escherichia coli. Although with low translational efficiency, the expression of the Clostridium selenoprotein msrA gene in E. coli could be demonstrated by 75Se metabolic labeling, immunoblot analyses, and enzyme assays, indicating that its SECIS element was recognized by the E. coli Sec insertion machinery. We found that the Sec-containing MsrA exhibited at least a 20-fold higher activity than its Cys mutant form, indicating a critical role of Sec in the catalytic activity of the enzyme. Furthermore, our data revealed that the Clostridium MsrA was inefficiently reducible by thioredoxin, which is a typical reducing agent for MsrA, suggesting the use of alternative electron donors in this anaerobic bacterium that directly act on the selenenic acid intermediate and do not require resolving Cys residues
Bonghan Ducts as Possible Pathways for Cancer Metastasis
Objective: The present study has been designed to find a possible new route for the
metastasis of cancer cells on the fascia surrounding tumor tissue using a novel technique
of trypan blue staining.
Materials and Methods: Tumor tissues were grown in the skin of nude mice after subcutaneous
inoculation with human lung cancer cells. Trypan blue was recently identified
as a dye with specificity for Bonghan ducts (BHDs) and not other tissues, such as
blood or lymph vessels or nerves.
Results: We demonstrate that the trypan blue staining technique allows the first
visualization of BHDs which are connected to tumor tissues
Bonghan Ducts as Possible Pathways for Cancer Metastasis
Objective: The present study has been designed to find a possible new route for the
metastasis of cancer cells on the fascia surrounding tumor tissue using a novel technique
of trypan blue staining.
Materials and Methods: Tumor tissues were grown in the skin of nude mice after subcutaneous
inoculation with human lung cancer cells. Trypan blue was recently identified
as a dye with specificity for Bonghan ducts (BHDs) and not other tissues, such as
blood or lymph vessels or nerves.
Results: We demonstrate that the trypan blue staining technique allows the first
visualization of BHDs which are connected to tumor tissues
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