694 research outputs found
Air pollutant production by algal cell cultures
The production of phytotoxic air pollutants by cultures of Chlorella vulgaris and Euglena gracilis is considered. Algal and plant culture systems, a fumigation system, and ethylene, ethane, cyanide, and nitrogen oxides assays are discussed. Bean, tobacco, mustard green, cantaloupe and wheat plants all showed injury when fumigated with algal gases for 4 hours. Only coleus plants showed any resistance to the gases. It is found that a closed or recycled air effluent system does not produce plant injury from algal air pollutants
NASA aviation safety reporting system
The origins and development of the NASA Aviation Safety Reporting System (ASRS) are briefly reviewed. The results of the first quarter's activity are summarized and discussed. Examples are given of bulletins describing potential air safety hazards, and the disposition of these bulletins. During the first quarter of operation, the ASRS received 1464 reports; 1407 provided data relevant to air safety. All reports are being processed for entry into the ASRS data base. During the reporting period, 130 alert bulletins describing possible problems in the aviation system were generated and disseminated. Responses were received from FAA and others regarding 108 of the alert bulletins. Action was being taken with respect to 70 of the 108 responses received. Further studies are planned of a number of areas, including human factors problems related to automation of the ground and airborne portions of the national aviation system
CO and trans-cinnamaldehyde as corrosion inhibitors of I825, L80-13Cr and N80 alloys in concentrated HCl solutions at high pressure and temperature
Peer reviewedPostprin
Algorithms to automatically quantify the geometric similarity of anatomical surfaces
We describe new approaches for distances between pairs of 2-dimensional
surfaces (embedded in 3-dimensional space) that use local structures and global
information contained in inter-structure geometric relationships. We present
algorithms to automatically determine these distances as well as geometric
correspondences. This is motivated by the aspiration of students of natural
science to understand the continuity of form that unites the diversity of life.
At present, scientists using physical traits to study evolutionary
relationships among living and extinct animals analyze data extracted from
carefully defined anatomical correspondence points (landmarks). Identifying and
recording these landmarks is time consuming and can be done accurately only by
trained morphologists. This renders these studies inaccessible to
non-morphologists, and causes phenomics to lag behind genomics in elucidating
evolutionary patterns. Unlike other algorithms presented for morphological
correspondences our approach does not require any preliminary marking of
special features or landmarks by the user. It also differs from other seminal
work in computational geometry in that our algorithms are polynomial in nature
and thus faster, making pairwise comparisons feasible for significantly larger
numbers of digitized surfaces. We illustrate our approach using three datasets
representing teeth and different bones of primates and humans, and show that it
leads to highly accurate results.Comment: Changes with respect to v1, v2: an Erratum was added, correcting the
references for one of the three datasets. Note that the datasets and code for
this paper can be obtained from the Data Conservancy (see Download column on
v1, v2
A scaling law for the cosmological constant from a stochastic model for cosmic structures
A set of scaling laws, based on the stochastic motions of the granular
components of astronomical systems, is applied to a cosmological model with a
positive cosmological constant. It follows that the mass of the dominant
particle in the observable universe must be proportional to the sixth root of
the cosmological constant and of the order of the nucleon mass, which is
consistent with the Zeldovich scaling law. The approach is a natural way to
solve the cosmic coincidence problem. On the other hand, the observed value of
the cosmological constant emerges as the result of a scaling law induced by the
stochastic mechanism which gives rise to the gravitationally bound systems.Comment: 7 pages, 2 figure
Apical secretory glycoprotein complex contributes to cell attachment and entry by Cryptosporidium parvum
Cryptosporidium parvum is an enteric pathogen that invades epithelial cells in the intestine, where it resides at the apical surface in a unique epicellular location. Compared with those of related apicomplexan parasites, the processes of host cell attachment and invasion by C. parvum are poorly understood. The streamlined C. parvum genome contains numerous mucin-like glycoproteins, several of which have previously been shown to mediate cell attachment, although the majority are unstudied. Here, we identified the antigens recognized by monoclonal antibody (MAb) 1A5, which stains the apical end of sporozoites and mature merozoites. Immunoprecipitation with MAb 1A5 followed by mass spectrometry identified a heterodimer comprised of paralogous proteins which are related to additional orthologs in the genome of C. parvum and related species. Paralogous glycoproteins recognized by MAb 1A5 heterodimerize as a complex displayed on the parasite surface, and they also interact with lectins that suggest that they contain mucin-like, O-linked oligosaccharides. Although the gene encoding one of the paralogs was readily disrupted by CRISPR/Cas9 gene editing, its partner, which contains a mucin-like domain related to GP900, was refractory to deletion. Combined with the ability of MAb 1A5 to partially neutralize host cell attachment by sporozoites, these findings define a new family of secretory glycoproteins that participate in cell invasion b
Integrated Vehicle-Based Safety System (IVBSS): Heavy truck extended pilot test summary report
This report describes the findings and recommendations from the heavy-truck (HT) extended pilot test (EPT) conducted by University of Michigan Transportation Research Institute (UMTRI) and its partners under the Integrated Vehicle-Based Safety Systems (IVBSS) program. The EPT was conducted to provide evidence of system performance (alert rate and reliable operation) and driver acceptance prior to conduct of the field operational test (FOT). The results of this test were to be used to modify the HT system performance and functionality as required, prior to the start of the FOT. The EPT entailed use of an integrated crash warning system in a heavy truck by seven drivers, over a period of five days each, in the course of their regular duties as drivers for Con-way Freight at the Ann Arbor distribution center. The test lasted four weeks starting on November 10 and ending December 12, 2008; the resultant data represent 5,300 miles of system use. The extended pilot test of the heavy truck platform on the IVBSS program successfully evaluated system performance and driver acceptance. Driver recruitment and training procedures were tested, as were the driver survey and debriefing methodologies. The warning system and data acquisition hardware operated reliably through the EPT. However, the warning system had an alert rate that was higher than anticipated based on previous testing. Nonetheless, drivers were generally still accepting of the system. Valuable data obtained from the EPT have led to further system performance improvements in the detection of stopped and slower-moving objects by the FCW subsystem in order to reduce the alert rate, and these enhancements have been implemented into the heavy truck fleet for the full field operational test.U.S. Department of Transportationhttp://deepblue.lib.umich.edu/bitstream/2027.42/62989/1/102284.pd
Inter-species variation in colour perception
Inter-species variation in colour perception poses a serious problem for the view that colours are mind-independent properties. Given that colour perception varies so drastically across species, which species perceives colours as they really are? In this paper, I argue that all do. Specifically, I argue that members of different species perceive properties that are determinates of different, mutually compatible, determinables. This is an instance of a general selectionist strategy for dealing with cases of perceptual variation. According to selectionist views, objects simultaneously instantiate a plurality of colours, all of them genuinely mind-independent, and subjects select from amongst this plurality which colours they perceive. I contrast selectionist views with relationalist views that deny the mind-independence of colour, and consider some general objections to this strategy
Human papillomavirus in head and neck squamous cell carcinoma: A descriptive study of histologically confirmed cases at Kamuzu Central Hospital in Lilongwe, Malawi
Background: Head and neck squamous cell carcinoma (HNSCC) is common in sub-Saharan Africa, but the aetiologic contribution of human papillomavirus (HPV) is not well established.Methods: We assessed HNSCC cases for HPV using p16 immunohistochemistry (IHC) in Malawi. Associations between p16 IHC and tumour site, behavioural risk factors, demographic characteristics, and HIV status were examined.Results: From 2010 to 2014, 77 HNSCC cases were identified. Mean age was 52 years, 50 cases (65%) were male, and 48 (62%) were in the oropharynx (OP) or oral cavity (OC). HIV status was known for 35 patients (45%), with 5 (14%) HIV-infected. Substance use was known for 40 patients (52%), with 38% reporting any tobacco and 31% any alcohol. Forty-two cases (55%) had adequate tissue for p16 IHC, of which seven (17%) were positive, including 22% of OP/OC tumours.Conclusions: Despite high cervical cancer burden, HPV-associated HNSCC is not very common in Malaw
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