Miracle-dz/UniFAR-FTUs huggingface dataset:
A free radical flavoprotein from Azotobacter. Isolation, crystallization, and properties.

Abstract A flavoprotein containing flavin mononucleotide has been isolated from Azotobacter vinelandii, purified to homogeneity, and crystallized. Anaerobically prepared flavoprotein exhibited free radical properties and absorption maxima at 580 and 615 mµ, suggestive of a flavin semiquinone. The flavoprotein is unusual in that the oxidized form reacts slowly even with strong reducing agents (Na2S2O4) and is resistant to reduction beyond the half-reduced state; anaerobically prepared flavoprotein is exceptionally resistant to oxidation by molecular oxygen. These unusual properties have been shown to be dependent upon the structural integrity of the protein.
Characterization of the DNA of a Nonoccluded Baculovirus, Hz-1V

The DNA of the nonoccluded baculovirus (Hz-1V) obtained from the IMC-Hz-1 cell line was characterized by physicochemical and restriction endonuclease techniques. Hz-1V DNA isolated from purified virus had buoyant densities of 1.58 and 1.54 g/ml in CsCl-ethidium bromide density gradients, which corresponded to supercoiled and to relaxed circular and linear DNA, respectively. Neutral CsCl equilibrium centrifugation indicated that the Hz-1V DNA had a buoyant density of 1.7024 g/ml, which corresponded to a guanine-plus-cytosine (G+C) content of 43%. Thermal denaturation indicated a high G+C domain(s) in the Hz-1V genomic DNA. The domain(s), which included about 11% of the total genomic DNA, exhibited a Tm of 97°C. The remaining portion (89%) of the DNA had a Tm of 86.5°C. The Tms corresponded to G+C contents of 42 and 67%, respectively. The mean genetic complexity of Hz-1V DNA determined by DNA reassociation kinetic analysis was found to be 152 × 106. A possible rapidly reassociating component comprising approximately 13% of the genome was observed. The mean molecular weights from restriction endonuclease digests were 159 × 106 for both HindIII and EcoRI. Genomic heterogeneity was found in both the wild-type Hz-1V stock and in two plaque isolates. Of 12 single-plaque isolates, 3 basic restriction endonuclease DNA fragment patterns were observed. The molecular size estimates from electron microscopic contour lengths of uncloned viral DNA ranged from 70 to 158 megadaltons, and the mode was the 130- to 140-megadalton class.
Oceanographic Fronts Shape Phaeocystis Assemblages: A High-Resolution 18S rRNA Gene Survey From the Ice-Edge to the Equator of the South Pacific

The cosmopolitan haptophyte Phaeocystis is recognized as a key contributor to marine biogeochemical cycling and important primary producer within polar marine environments. Yet, little is known about its solitary, non-colonial cell stages or its distribution during the colder, low-productivity seasons. We examined the biogeography of Phaeocystis along a high-resolution (0.5-degree latitudinal interval) transect from the Antarctic ice-edge to the equator of the South Pacific, in the austral autumn-winter. Using high-throughput 18S rRNA gene sequences with single nucleotide variable (zero-radius) operational taxonomic units (zOTUs) allowed us to explore the possibility of strain-level variation. From water samples within the upper water column, we show the presence of an abundant Phaeocystis assemblage that persisted during the colder months, contributing up to 9% of the microbial eukaryote community at high latitudes. The biogeography of Phaeocystis was strongly shaped by oceanographic boundaries, most prominently the polar and subantarctic fronts. Marked changes in dominant Phaeocystis antarctica zOTUs between different frontal zones support the concept that ecotypes may exist within the Phaeocystis assemblage. Our findings also show that the Phaeocystis assemblage did not abide by the classical latitudinal diversity gradient of increasing richness from the poles to the tropics; richness peaked at 30°S and declined to a minimum at 5°S. Another surprise was that P. globosa and P. cordata, previously thought to be restricted to the northern hemisphere, were detected at moderate abundances within the Southern Ocean. Our results emphasize the importance of oceanographic processes in shaping the biogeography of Phaeocystis and highlights the importance of genomics-based exploration of Phaeocystis, which have found the assemblage to be more complex than previously understood. The high winter relative abundance of the Phaeocystis assemblage suggests it could be involved in more complex ecological interactions during the less productive seasons, which should be considered in future studies to better understand the ecological role and strategies of this keystone species.
New Optical Tools to Study Neural Circuit Assembly in the Retina

During development, neurons navigate a tangled thicket of thousands of axons and dendrites to synapse with just a few specific targets. This phenomenon termed wiring specificity, is critical to the assembly of neural circuits and the way neurons manage this feat is only now becoming clear. Recent studies in the mouse retina are shedding new insight into this process. They show that specific wiring arises through a series of stages that include: directed axonal and dendritic growth, the formation of neuropil layers, positioning of such layers, and matching of co-laminar synaptic partners. Each stage appears to be directed by a distinct family of recognition molecules, suggesting that the combinatorial expression of such family members might act as a blueprint for retinal connectivity. By reviewing the evidence in support of each stage, and by considering their underlying molecular mechanisms, we attempt to synthesize these results into a wiring model which generates testable predictions for future studies. Finally, we conclude by highlighting new optical methods that could be used to address such predictions and gain further insight into this fundamental process.
Sulfide-Quinone Reductase from Rhodobacter capsulatus: Requirement for Growth, Periplasmic Localization, and Extension of Gene Sequence Analysis

ABSTRACT The entire sequence of the 3.5-kb fragment of genomic DNA fromRhodobacter capsulatus which contains the sqrgene and a second complete and two further partial open reading frames has been determined. A correction of the previously publishedsqr gene sequence (M. Schütz, Y. Shahak, E. Padan, and G. Hauska, J. Biol. Chem. 272:9890–9894, 1997) which in the deduced primary structure of the sulfide-quinone reductase changes four positive into four negative charges and the number of amino acids from 425 to 427 was necessary. The correction has no further bearing on the former sequence analysis. Deletion and interruption strains document that sulfide-quinone reductase is essential for photoautotrophic growth on sulfide. The sulfide-oxidizing enzyme is involved in energy conversion, not in detoxification. Studies with an alkaline phosphatase fusion protein reveal a periplasmic localization of the enzyme. Exonuclease treatment of the fusion construct demonstrated that the C-terminal 38 amino acids of sulfide-quinone reductase were required for translocation. An N-terminal signal peptide for translocation was not found in the primary structure of the enzyme. The possibility that the neighboring open reading frame, which contains a double arginine motif, may be involved in translocation has been excluded by gene deletion (rather, the product of this gene functions in an ATP-binding cassette transporter system, together with the product of one of the other open reading frames). The results lead to the conclusion that the sulfide-quinone reductase of R. capsulatus functions at the periplasmic surface of the cytoplasmic membrane and that this flavoprotein is translocated by a hitherto-unknown mechanism.
Enhanced methane production from pig slurry with pulsed electric field pre-treatment

ABSTRACT Intensive amount of manure produced in pig breeding sectors represents negative impact on the environment and requires optimal management. Anaerobic digestion as a well-known manure management process was optimized in this experimental study by pulsed electric field (PEF) pre-treatment. The effect of PEF on methane production was investigated at three different intensities (15, 30 and 50 kWh/m3). The results indicate that the methane production and chemical oxygen demand (COD) removal was improved by continuous escalation of applied intensity, up to 50 kWh/m3. In comparison with untreated slurry, methane production and COD removal were increased up to 58% and 44%, respectively.
Suppression and (2f1-f2)-difference tones in a nonlinear cochlear preprocessing model with active feedback.

The two nonlinear effects of two-tone suppression and of (2f1-f2)-difference tone creation are measured in a hardware model which consists of 90 sections containing nonlinear feedback loops. The basic data are the level and phase distributions along the 90 sections produced by single tones in the linear passive system which are almost identical to those produced in the nonlinear active system at high levels. Enhancement is created at medium and low input levels resulting in more strongly peaked level-place patterns. Two-tone suppression is, therefore, described as a "de-enhancement" which is produced by the gain reduction in the saturating nonlinearity of the feedback loop in consequence of increasing input levels (that of the feedback loop in consequence of increasing input levels (that of the suppressor as well! ). Characteristics of suppression are given in normalized form. The creation of (2f1-f2)-difference tones is based on the same nonlinear effects. In each section, difference-tone wavelets are created which travel--changing level and phase thereby--to their characteristic place, where they add up to a vector sum corresponding to the audible difference tone. In case of cancellation, the vector sum has to be compensated by an additional tone of the same frequency and amount but opposite phase. Based on this strategy of (2f1-f2)-difference tone development, the relevant relations are measured on the model and averaged either in normalized graphs or in equations in order to offer the possibility to simulate the hardware model on the computer. Psychoacoustically measured cancellation data are compared with data measured using the model. The two data sets agree not only in general but also in many details indicating that the model describes cochlear nonlinear preprocessing to a useful approximation.
Comments on 'Residue arithmetic VLSI array architecture for manipulator pseudo-inverse Jacobian computation' [with reply]

The commenter indicates that in the above-mentioned paper (see ibid., vol.5, no.5, p.569-82 (1989)) the proposed pipelined array architecture for the mixed-radix conversion problem is not as efficient and suitable for VLSI implementation as claimed. The commenter identifies the shortcomings of the design and then gives an efficient systolic/wavefront array that requires fewer hardware resources. The authors reply that this is another valid design for the mixed-radix conversion problem that avoids broadcasting; however, the triangular array of buffers is still required in the design for the data-format conversion, and this problem is not addressed. Since a semisystolic design was not given, the comparison between the original design and the semisystolic design in terms of buffers is premature. >
Requirement for CD4 T Cell Help in Generating Functional CD8 T Cell Memory

Although primary CD8 responses to acute infections are independent of CD4 help, it is unknown whether a similar situation applies to secondary responses. We show that depletion of CD4 cells during the recall response has minimal effect, whereas depletion during the priming phase leads to reduced responses by memory CD8 cells to reinfection. Memory CD8 cells generated in CD4+/+ mice responded normally when transferred into CD4−/− hosts, whereas memory CD8 cells generated in CD4−/− mice mounted defective recall responses in CD4+/+ adoptive hosts. These results demonstrate a previously undescribed role for CD4 help in the development of functional CD8 memory.
Knowledge Sharing and Factors Influencing Sharing in Libraries - A Pilot Study on the Knowledge Sharing Attributes of the Education City Library Community in Qatar

Purpose — The purpose of this pilot study is to understand the knowledge sharing attributes of the librarians in the Education City libraries and to identify the impending factors that affect the sharing process. This pilot study is part of a country wide study on the aspects of knowledge sharing in libraries. Findings — The results showed that library professionals in the Education City, Qatar were involved in a lot of knowledge sharing activities among colleagues within their library and other libraries. The result also identifies the knowledge sources and with whom they share what. It was also found that cultural differences, language and library policies are important factors that have impacted significantly the flow of knowledge in the expatriate library community. Research limitations/implications — The coverage on the universities in this paper is confined primarily to Education City, where majority of the universities are present. However, future research could include the few other universities/colleges that are out of the ambit of Education City to have a wider population in the study. Practical implications — This paper has practical implications for those who are not fully aware of the working conditions in this region and Qatar in particular. It provides a useful overview of the knowledge sharing trends and requirements and the impediments to sharing vital knowledge that would help professionals in gaining some knowledge about the constraints and be prepared. Originality/Value — There are no previous studies undertaken on knowledge sharing among library professionals in this region. This is the first ever study undertaken to understand the knowledge sharing attributes and trends among librarians in Qatar. So this study would be in the interest of all the library professionals that are contemplating an international career in this region and also understand the cultural and other differences when they arrive.
Late Complications of Incisional Hernias Following Prosthetic Mesh Repair

Abstract Background: Incisional hernias still continue to be a serious problem for surgeons. In this study, we aimed to investigate the effects of polypropylene mesh and mersilene mesh, which are frequently employed in incisional hernias, as well as the effects of their application techniques on late complications. Methods: Two-hundred-sixty-four open abdominal hernia repairs were performed between 1986–2000, using prosthetic materials: polypropylene mesh and mersilene mesh were used in hernia repair. Mesh was placed as onlay, underlay and sandwich techniques. Follow-up data were obtained from medical records. Results: Comparisons were made with respect to surgical techniques and to late complications such as recurrence, ente-rocutaneous fistula, intestinal obstruction, and infections. Enterocutaneous fistulas developed in two patients. Recurrence occurred in 6.4 per cent. Chronic infection and wound sinus formation occurred in 5 per cent. The causes of recurrence included smoking, cellulitis, chronic infection/sinus tract, upper abdominal localization, and obstruction. Fistula formation occurred in patients with no peritoneal prevention, which was statistically significant (p=0.012). Chronic infection/sinus tract was high in patients for whom mersilene mesh was used, and enterocutaneous fistula occurred in 2 patients. Conclusion: To prevent late complications, it is necessary to avoid the contact of mesh with bowel.
Design of a double array lens

The aim of the paper below is to present a particular structure, working as if it were a double array lens (transmitarray). The structure consists of a patch array in the reception part, a phase delay for each patch and another patch array in the transmission part. The idea in using this device is to place it in front of a particular antenna in order to modify the radiation pattern of the feeding antenna. The architecture that is being applied implies the use of patches with via feeding. To avoid undesired coupling between the reception and the transmission arrays, ground planes that isolate the reception array, the phase delay and the transmission array are placed. In this paper the phase delay part, the radiation part and the whole structure are analyzed and simulated. Finally, some prototypes for the phase delay structure are presented.
Identifying Root Causes of Construction Accidents

Construction accident investigation techniques and reporting systems identify what type of accidents occur and how they occurred. Unfortunately, they do not properly address why the accident occurred by identifying possible root causes, which is only possible by complementing these techniques with theories of accident causation and theories of human error. The uniqueness of the construction industry dictates the need to tailor many of the contemporary accident causation models and human error theories. This paper presents an accident root causes tracing model (ARCTM) tailored to the needs of the construction industry. ARCTM proposes that accidents occur due to three root causes: (1) Failing to identify an unsafe condition that existed before an activity was started or that developed after an activity was started; (2) deciding to proceed with a work activity after the worker identifies an existing unsafe condition; and (3) deciding to act unsafe regardless of initial conditions of the work environment. In .
Domain-induced budding of vesicles.

Phase separation within the fluid membrane of a vesicle can lead to domain-induced budding. This shape transformation should occur both for the spinodal decomposition and for the nucleation regime and should be observable in quench experiments on phospholipid-cholesterol vesicles. The budding process leads to limit shapes for which the bud is connected by an infinitesimal neck to the original vesicle. This neck can be characterized by a general relation for the principal curvatures of the adjacent membrane segments. The effect of the Gaussian curvature on the shape is also discussed.
Performance of Database Driven Network Applications from the User Perspective

An understanding of performance of database driven network applications is critical in combating slow performance of e-commerce web sites, besides efficient web page design, and high quality and well-maintained web server equipment. This paper describes a method of measuring performance from the user viewpoint, which can help enormously in making realistic assessment of true performance of database driven applications. The performance measurements were taken at user locations by using several specially designed JavaScript functions along with ASP scripts. A performance study is presented in this paper, comparing performance of data access using stored procedures with the traditional way of querying a database. It is generally believed that stored procedures have performance benefits as they are pre-compiled. However, our study shows that the data access approach using stored procedures provides significant benefits (by about 30%) over the traditional approach for querying a commercial MySQL database, only when retrieving a substantial amount of data (at least 10,000 rows of data).
A comparative study on shadow compensation of color aerial images in invariant color models

In urban color aerial images, shadows cast by cultural features may cause false color tone, loss of feature information, shape distortion of objects, and failure of conjugate image matching within the shadow area. This paper presents an automatic property-based approach for the detection and compensation of shadow regions with shape information preserved in complex urban color aerial images for solving problems caused by cast shadows in digital image mapping. The technique is applied in several invariant color spaces that decouple luminance and chromaticity, including HSI, HSV, HCV, YIQ, and YC/sub b/C/sub r/ models. Experimental results from de-shadowing color aerial images of a complex building and a highway segment in these color models are evaluated in terms of visual comparisons and shadow detection accuracy assessments. The results show the effectiveness of the proposed approach in revealing details under shadows and the suitability of these color models in de-shadowing urban color aerial images.
DEA evaluation of bank branch performance

In today's economy and society, performance analyses in the services industries attract more and more attention. This paper presents an evaluation of 766 branches of one big Canadian bank in Ontario and Quebec provinces during the period of April 2000 to March 2001 using DEA. Special emphasis was placed on discussing whether the results would be realistic when applied to the other branches. Finally the potential management uses of the DEA results were presented.
Obesity, haemostasis and the fibrinolytic system

Obese patients are at risk for the development of cardiovascular diseases, which can in part be explained by disturbances in the haemostatic and fibrinolytic systems. Indeed, obese subjects tend to have higher values of fibrinogen, factor VII, factor VIII, von Willebrand factor and plasminogen activator inhibitor compared to non‐obese subjects. Abdominal obesity, in particular, has been shown to be associated with disturbances in fibrinogen, factor VIII and von Willebrand factor, while less consistent results have been found for factor VII. Recently it has been demonstrated that the adipocyte itself is able to produce plasminogen activator inhibitor‐1, possibly explaining the high levels found in obesity. Different studies have investigated the association between haemostatic and fibrinolytic parameters and the insulin resistance syndrome, often present in obese subjects. Fibrinogen has been found to be related to insulin, but it has been suggested that this relationship is not independent of the accompanying inflammatory reaction. Results from studies on the relationship between insulin resistance and factor VII, factor VIII and von Willebrand factor levels are inconsistent. In contrast, plasminogen activator inhibitor‐1 has been found to correlate with all components of the insulin resistance syndrome, and can be considered as a true component of this metabolic syndrome. Weight loss seems to have a beneficial effect on factor VII – probably mediated through a reduction in triglycerides. Data on factor VIII and von Willebrand factor are scarce but weight loss does not seem to have an effect. Fibrinogen does not seem to be reduced by modest weight loss and a more substantial weight loss seems necessary to lower fibrinogen levels. In contrast, both modest and substantial weight loss have been found to significantly reduce plasminogen activator inhibitor‐1 levels. In conclusion, the increased cardiovascular risk observed in obesity could in part be explained by the association between insulin resistance and components of the fibrinolytic and haemostatic systems. Whether this relationship is truly causal or indirect needs to be elucidated further.