1,407 research outputs found
Reduced impact logging guidelines for lowland and hill dipterocarp forest in Indonesia
U ovom radu opisana je tehnologija mehaničke obrade, sa svim operacijama koje su specifične za proizvodnju cijevi oružja. U uvodnom dijelu definiran je pojam streljačkog oružja sa tehnološkom problematikom u izradi i specifičnostima u eksploataciji cijevi. Kroz pojašnjenja namjene, materijala i konstrukcije cijevi, spomenute su tehnologije obrade koje su nužne za kvalitetnu izradu cijevi streljačkog naoružanja. Na kraju je opisan tehnološki postupak izrade cijevi u standardnom NATO kalibru 5,56x45 mm, zajedno sa ključnim točkama u kojima je potrebna posebna pozornost, kako bi se izbjegle greške.This paper describes the mechanical processing technology with all operations that are specific to the production of gun barrels. The introductory section defines the concept of infantry weapon with the technological issues in manufacturing and specificity of barrel exploitation. Through the clarification of the purpose, materials and construction of the barrel, the processing technologies are mentioned which are necessary factor in producing a barrel for infantry weapon. At the end, a technological process of a weapon barrel manufacturing in the standard NATO 5.56x45 mm caliber is described, along with key points where special attention is needed to avoid mistakes
Intracerebral Hemorrhage and Ischemic Stroke of Different Etiologies Have Distinct Alternatively Spliced mRNA Profiles in the Blood: a Pilot RNA-seq Study.
Whole transcriptome studies have used 3'-biased expression microarrays to study genes regulated in the blood of stroke patients. However, alternatively spliced messenger RNA isoforms have not been investigated for ischemic stroke or intracerebral hemorrhage (ICH) in animals or humans. Alternative splicing is the mechanism whereby different combinations of exons of a single gene produce distinct mRNA and protein isoforms. Here, we used RNA sequencing (RNA-seq) to determine if alternative splicing differs for ICH and cardioembolic, large vessel and lacunar causes of ischemic stroke compared to controls. RNA libraries from 20 whole blood samples were sequenced to 200 M 2 × 100 bp reads using Illumina sequencing-by-synthesis technology. Differential alternative splicing was assessed using one-way analysis of variance (ANOVA), and differential exon usage was calculated. Four hundred twelve genes displayed differential alternative splicing among the groups (false discovery rate, FDR; p < 0.05). They were involved in cellular immune response, cell death, and cell survival pathways. Distinct expression signatures based on usage of 308 exons (292 genes) differentiated the groups (p < 0.0005; fold change >|1.2|). This pilot study demonstrates that alternatively spliced genes from whole blood differ in ICH compared to ischemic stroke and differ between different ischemic stroke etiologies. These results require validation in a separate cohort
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Timber harvest layout by mathematical and Heuristic programming
Although some of the most difficult problems in forest management occur as a result of timber harvest operations, present methodology in harvest planning emphasizes guidelines which rely heavily upon the experience of the individual forest manager for their correct application. This study was undertaken in an effort to develop a comprehensive methodology to assist forest managers in the design of timber harvest cutting units and the assignment of logging equipment: to those units. The objective of the methodology is to maximize the total value of the timber harvested from a planning area, net of variable and fixed harvesting and transportation costs. The methodology thus developed consists of a two-part procedure. The first part considers the specific topographic and timber conditions on the planning area, plus any harvesting restrictions which may have been imposed on portions of the area because of expected environmental problems, This information is combined with the known mechanics of the logging systems under consideration to determine the feasibility and cost of harvesting each parcel of timber from the area. The second part of the methodology consists of a heuristic optimization algorithm which seeks to assign timber parcels to harvesting facilities so that total timber value, net of fixed and variable harvesting and transportation costs, is maximized. The output from this algorithm is a detailed harvest plan which specifies yarding system assignments and the physical layout of cutting units for each yarding system thus assigned. The optimization problem confronted in this study is an application of facilities location theory, but with two unique characteristics which render the conventional mixed integer programming formulation unsuitable for this problem. First, the planning area is visualized as being dichotomized into timber parcels of equal size, each of which is to be assigned to some harvesting facility. Thus, the problem is a fully discrete one, and can be formulated as a 0-1 integer programming problem. Second, the problem exhibits a special "cascading fixed charge" structure. Stated simply, this implies that several levels of fixed charges must be incurred for any complete facility installation. Thus, if a specific logging cableway is to be emplaced at a certain landing, then the fixed charge associated with the construction of the landing must already have been incurred, and the fixed charge associated with the installation of some yarding system at the landing must also have been incurred. Unfortunately the 0-1 integer programming formulation appropriate for this problem requires many thousands of variables and constraints, even for relatively small planning areas. To overcome the computational difficulties associated with the solution of such large integer programming problems, a heuristic algorithm was developed to find satisfactory, rather than optimal solutions. Applied to a realistic forest planning problem with 5507 variables and 6555 constraints, the algorithm found an initial feasible solution after 93.3 minutes on a CDC 3300 computer. The run was terminated after a total of 120 minutes, with the value of the final solution being only 0.09 percent better than that of the initial solution. Although the exact solution could not be verified, computational experience with smaller problems suggests that the initial feasible solution obtained with this algorithm is usually very close to the optimal solution
Conceptual Development About Motion and Force in Elementary and Middle School Students
Methods of physics education research were applied to find what kinds of changes in 4th, 6th, and 8th grade student understanding of motion can occur and at what age. Such findings are necessary for the physics community to effectively discharge its role in advising and assisting pre-college physics education. Prior to and after instruction the students were asked to carefully describe several demonstrated accelerated motions. Most pre-instruction descriptions were of the direction of motion only. After instruction, many more of the students gave descriptions of the motion as continuously changing. Student responses to the diagnostic and to the activity materials revealed the presence of a third “snapshot” view of motion not discussed in the literature. The 4th and 6th grade students gave similar pre-instructional descriptions of the motion, but the 4th grade students did not exhibit the same degree of change in descriptions after instruction. Our findings suggest that students as early as 6th grade can develop changes in ideas about motion needed to construct Newtonian-like ideas about force. Students’ conceptions about motion change little under traditional physics instruction from these grade levels through college level
Elevating microRNA-122 in blood improves outcomes after temporary middle cerebral artery occlusion in rats.
Because our recent studies have demonstrated that miR-122 decreased in whole blood of patients and in whole blood of rats following ischemic stroke, we tested whether elevating blood miR-122 would improve stroke outcomes in rats. Young adult rats were subjected to a temporary middle cerebral artery occlusion (MCAO) or sham operation. A polyethylene glycol-liposome-based transfection system was used to administer a miR-122 mimic after MCAO. Neurological deficits, brain infarction, brain vessel integrity, adhesion molecule expression and expression of miR-122 target and indirect-target genes were examined in blood at 24 h after MCAO with or without miR-122 treatment. miR-122 decreased in blood after MCAO, whereas miR-122 mimic elevated miR-122 in blood 24 h after MCAO. Intravenous but not intracerebroventricular injection of miR-122 mimic decreased neurological deficits and brain infarction, attenuated ICAM-1 expression, and maintained vessel integrity after MCAO. The miR-122 mimic also down-regulated direct target genes (e.g. Vcam1, Nos2, Pla2g2a) and indirect target genes (e.g. Alox5, Itga2b, Timp3, Il1b, Il2, Mmp8) in blood after MCAO which are predicted to affect cell adhesion, diapedesis, leukocyte extravasation, eicosanoid and atherosclerosis signaling. The data show that elevating miR-122 improves stroke outcomes and we postulate this occurs via downregulating miR-122 target genes in blood leukocytes
Determining Training Needs for Cloud Infrastructure Investigations using I-STRIDE
As more businesses and users adopt cloud computing services, security
vulnerabilities will be increasingly found and exploited. There are many
technological and political challenges where investigation of potentially
criminal incidents in the cloud are concerned. Security experts, however, must
still be able to acquire and analyze data in a methodical, rigorous and
forensically sound manner. This work applies the STRIDE asset-based risk
assessment method to cloud computing infrastructure for the purpose of
identifying and assessing an organization's ability to respond to and
investigate breaches in cloud computing environments. An extension to the
STRIDE risk assessment model is proposed to help organizations quickly respond
to incidents while ensuring acquisition and integrity of the largest amount of
digital evidence possible. Further, the proposed model allows organizations to
assess the needs and capacity of their incident responders before an incident
occurs.Comment: 13 pages, 3 figures, 3 tables, 5th International Conference on
Digital Forensics and Cyber Crime; Digital Forensics and Cyber Crime, pp.
223-236, 201
Geographic Differences in Event Rates by Model for End-Stage Liver Disease Score
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72232/1/j.1600-6143.2006.01508.x.pd
The Alpine Zone & Glacial Cirques of Mt. Washington & the Northern Presidential Range, New Hampshire
A treatment planning intercomparison of proton and intensity modulated photon radiotherapy.
peer reviewedAbstract
Purpose: A comparative treatment planning study has been undertaken between standard photon delivery techniques,b intensity modulated photon methods and spot scanned protons in order to investigate the merits and limitations of each of these treatment approaches.
Methods: Plans for each modality were performed using CT scans and planning information for nine patients with varying indications and lesion sites and the results have been analysed using a variety of dose and volume based parameters.
Results: Over all cases, it is predicted that the use of protons could lead to a reduction of the total integral dose by a factor three compared to standard photon techniques and a factor two compared to IM photon plans. In addition, in all but one Organ at Risk (OAR) for one case, protons are predicted to reduce both mean OAR dose and the irradiated volume at the 50% mean target dose level compared to both photon methods. However, when considering the volume of an OAR irradiated to 70% or more of the target dose, little difference could be shown between proton and intensity modulated photon plans. On comparing the magnitude of dose hot spots in OARs resulting from the proton and IM photon plans, more variation was observed, and the ranking of the plans was then found to be case and OAR dependent.
Conclusions: The use of protons has been found to reduce the medium to low dose load (below about 70% of the target dose) to OARs and all non-target tissues compared to both standard and inversely planned photons, but that the use of intensity modulated photons can result in similar levels of high dose conformation to that afforded by protons. However, the introduction of inverse planning methods for protons is necessary before general conclusions on the relative efficacy of photons and protons can be drawn
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