New technologies and disruptions related to Coronavirus disease-2019 have led to expansion of decentralized approaches to clinical trials. Remote tools and methods hold promise for increasing trial efficiency and reducing burdens and barriers by facilitating participation outside of traditional clinical settings and taking studies directly to participants. The Trial Innovation Network, established in 2016 by the National Center for Advancing Clinical and Translational Science to address critical roadblocks in clinical research and accelerate the translational research process, has consulted on over 400 research study proposals to date. Its recommendations for decentralized approaches have included eConsent, participant-informed study design, remote intervention, study task reminders, social media recruitment, and return of results for participants. Some clinical trial elements have worked well when decentralized, while others, including remote recruitment and patient monitoring, need further refinement and assessment to determine their value. Partially decentralized, or “hybrid” trials, offer a first step to optimizing remote methods. Decentralized processes demonstrate potential to improve urban-rural diversity, but their impact on inclusion of racially and ethnically marginalized populations requires further study. To optimize inclusive participation in decentralized clinical trials, efforts must be made to build trust among marginalized communities, and to ensure access to remote technology.

One challenge for multisite clinical trials is ensuring that the conditions of an informative trial are incorporated into all aspects of trial planning and execution. The multicenter model can provide the potential for a more informative environment, but it can also place a trial at risk of becoming uninformative due to lack of rigor, quality control, or effective recruitment, resulting in premature discontinuation and/or non-publication. Key factors that support informativeness are having the right team and resources during study planning and implementation and adequate funding to support performance activities. This communication draws on the experience of the National Center for Advancing Translational Science (NCATS) Trial Innovation Network (TIN) to develop approaches for enhancing the informativeness of clinical trials. We distilled this information into three principles: (1) assemble a diverse team, (2) leverage existing processes and systems, and (3) carefully consider budgets and contracts. The TIN, comprised of NCATS, three Trial Innovation Centers, a Recruitment Innovation Center, and 60+ CTSA Program hubs, provides resources to investigators who are proposing multicenter collaborations. In addition to sharing principles that support the informativeness of clinical trials, we highlight TIN-developed resources relevant for multicenter trial initiation and conduct.

The cross-slot stagnation point flow is one of the benchmark problems in non-Newtonian fluid mechanics as it allows large strains to develop and can therefore be used for extensional rheometry measurements or, once instability arises, as a mixing device. In such a flow, beyond a critical value for which the ratio of elastic force to viscous force is high enough, elasticity can break symmetry even in the absence of significant inertial forces (i.e. creeping flow), which is an unwanted phenomenon if the device is to be used as a rheometer but beneficial from a mixing perspective. In this work, a passive control mechanism is introduced to the cross-slot by adding a cylinder at the geometric centre to replace the ‘free’ stagnation point with ‘pinned’ stagnation points at the surface of the cylinder. In the current modified geometry, effects of the blockage ratio (the ratio of the diameter of the cylinder to the width of the channel), the Weissenberg number (the ratio of elastic forces to viscous forces) and extensibility parameters ($\unicode[STIX]{x1D6FC}$ and $L^{2}$) are investigated in two-dimensional numerical simulations using both the simplified Phan-Thien and Tanner and finitely extensible nonlinear elastic models. It is shown that the blockage ratio for fixed solvent-to-total-viscosity ratio has a stabilizing effect on the associated symmetry-breaking instability. The resulting data show that the suggested modification, although significantly changing the flow distribution in the region near the stagnation point, does not change the nature of the symmetry-breaking instability or, for low blockage ratio, the critical condition for onset. Using both numerical and physical experiments coupled with a supporting theoretical analysis, we conclude that this instability cannot therefore be solely related to the extensional flow near the stagnation point but it is more likely related to streamline curvature and the high deformation rates towards the corners, i.e. a classic ‘curved streamlines’ purely elastic instability. Our work also suggests that the proposed geometric modification can be an effective approach for enabling higher flow rates to be achieved whilst retaining steady symmetric flow.

Pressure-driven laminar and turbulent flow in a horizontal partially filled pipe was investigated using stereoscopic particle imaging velocimetry (S-PIV) in the cross-stream plane. Laminar flow velocity measurements are in excellent agreement with a recent theoretical solution in the literature. For turbulent flow, the flow depth was varied independently of a nominally constant Reynolds number (based on hydraulic diameter, $D_{H}$; bulk velocity, $U_{b}$ and kinematic viscosity $\unicode[STIX]{x1D708}$) of $Re_{H}=U_{b}D_{H}/\unicode[STIX]{x1D708}\approx 30\,000\pm 5\,\%$. When running partially full, the inferred friction factor is no longer a simple function of Reynolds number, but also depends on the Froude number $Fr=U_{b}/\sqrt{gD_{m}}$ where $g$ is gravitational acceleration and $D_{m}$ is hydraulic mean depth. S-PIV measurements in turbulent flow reveal the presence of secondary currents which causes the maximum streamwise velocity to occur below the free surface consistent with results reported in the literature for rectangular cross-section open channel flows. Unlike square duct and rectangular open channel flow the mean secondary motion observed here manifests only as a single pair of vortices mirrored about the vertical bisector and these rollers, which fill the half-width of the pipe, remain at a constant distance from the free surface even with decreasing flow depth for the range of depths tested. Spatial distributions of streamwise Reynolds normal stress and turbulent kinetic energy exhibit preferential arrangement rather than having the same profile around the azimuth of the pipe as in a full pipe flow. Instantaneous fields reveal the signatures of elements of canonical wall-bounded turbulent flows near the pipe wall such as large-scale and very-large-scale motions and associated hairpin packets whilst near the free surface, the signatures of free surface turbulence in the absence of imposed mean shear such as ‘upwellings’, ‘downdrafts’ and ‘whirlpools’ are present. Two-point spatio-temporal correlations of streamwise velocity fluctuation suggest that the large-scale coherent motions present in full pipe flow persist in partially filled pipes but are compressed and distorted by the presence of the free surface and mean secondary motion.

We report the results of chemical sourcing of obsidian artifacts from Tres Zapotes using X-ray fluorescence analysis. This is the first obsidian sourcing study for this major Olmec and Epi-Olmec center in which samples are drawn from secure archaeological proveniences specifically assigned to Early, Middle, Late Formative, and Protoclassic periods. We employed a stratified random sampling strategy to select 180 obsidian artifacts from excavated assemblages, supplementing the random sample with another 24 specimens drawn from rare visual categories. Consequently, we are able to characterize changes in the relative importance of different obsidian sources in the political economy of Tres Zapotes across the critical transition from Olmec to Epi-Olmec society with greater confidence than has been possible for the Gulf lowlands while extending our observations to the full sample of 5,713 visually characterized obsidian artifacts—2,695 of which come from the well-dated Formative contexts examined in this article. Our study confirms the absence of obsidian from Otumba and from Guatemalan sources in the excavated Olmec assemblage in favor of sources from eastern Puebla and Veracruz, supporting a model of overlapping autonomous networks for obsidian procurement at Gulf Olmec sites. Presence of the Guatemalan San Martín Jilotepeque source in Epi-Olmec contexts may relate to the reestablishment of trans-Isthmian contacts, while increasing prevalence of Zaragoza-Oyameles obsidian from eastern Puebla marks the beginning of a long-term trend. Although more even representation of obsidian sources in Epi-Olmec contexts is consistent with the hypothesized transition from an exclusionary Olmec political economy toward a more “corporate” system associated with power sharing among factional leaders at Tres Zapotes, neither Olmec nor Epi-Olmec elites monopolized a particular obsidian source or technology.

Copper (I) oxide (Cu2O) is a direct band gap semiconductor with p-type conductivity and is a potential candidate for multi-junction solar cells. In this work, incoherent light source based photo-assisted metal-organic chemical vapor deposition (MOCVD) was used to deposit high quality Cu2O thin films on n-type <100> silicon and quartz substrates. X-ray diffraction studies reveal that crystalline Cu2O is deposited. UV-Vis-NIR spectroscopy results indicated a band gap of 2.44 eV for Cu2O thin films. Transmission electron spectroscopy results show that the Cu2O film grows in the form of three-dimensional islands composed of smaller nanocrystalline grains in the range of 10–20 nm. I–V measurements indicate that the Cu2O/n-Si device fabricated using the MOCVD process has a lower dark current density than other devices reported in the literature.

With modern undulators generating light of an arbitrary polarization state, experiments exploiting this feature in the soft X-ray region are becoming increasingly widespread. Circularly polarized light in the soft X-ray region is of particular interest to investigate of magnetic metals such as Fe, Co and Ni, and the rare earths. A versatile multilayer polarimeter has been designed and developed to characterize the polarization state of the soft X-ray beam. A W/B4C multilayer transmission phase retarder and reflection analyser has been used for polarimetry measurements on the beamline (I06) at Diamond Light Source. The design details of the polarimeter and preliminary polarimetry results are presented.

1. Non-specific stimulation of mice by a detergent lacking in vitro antibacterial activity, Triton WR 1339, produces a steady state in the course of experimental tuberculosis at about the same level as specific immunization, and does so independently of delayed allergy.

2. This effect is achieved in a much shorter time than is required by the normal immunological processes and the relative duration of enhanced resistance in each case is yet to be worked out.

3. Triton fails to enhance an existing, specifically acquired immunity.

4. There is no evidence so far that the mechanism involved is the same in both instances. If it were found to be the same, then the present concept of a specific cellular immunity would need to be revised.

Vertical extinction coefficients can be determined in water using selenium rectifier cells and colour filters. The cells are connected positive to negative with a simple 0-50 microammeter across the circuit, as in the Campbell-Freeth method. There is no deflexion when the two points of contact are brought to the same potential. This is done by lowering one cell into the sea to balance the rather less sensitive deck cell. The light reaching the latter is then reduced by the successive addition of opalized plates, to approximately 60, 30, 20 and 10 %, and the sea cell is lowered further to balance at each stage. The extinctions can then be calculated by the usual formula from the known percentage transmissions and the observed depths of balance. For each plate or combination a factor may thus be obtained which when divided by the appropriate depth gives the extinction. The method is rapid in operation and the drift error can be rendered negligible. The results agree with those found by the standard potentiometer method, but the applications of the new method are necessarily more limited.

Use of well persons as the comparison group for laboratory-confirmed cases of sporadic salmonellosis may introduce ascertainment bias into case-control studies. Data from the 1996–1997 FoodNet case-control study of laboratory-confirmed Salmonella serogroups B and D infection were used to estimate the effect of specific behaviours and foods on infection with Salmonella serotype Enteritidis (SE). Persons with laboratory-confirmed Salmonella of other serotypes acted as the comparison group. The analysis included 173 SE cases and 268 non-SE controls. SE was associated with international travel, consumption of chicken prepared outside the home, and consumption of undercooked eggs prepared outside the home in the 5 days prior to diarrhoea onset. SE phage type 4 was associated with international travel and consumption of undercooked eggs prepared outside the home. The use of ill controls can be a useful tool in identifying risk factors for sporadic cases of Salmonella.

Calliandra calothyrsus is a tree legume native to Mexico and Central America. The species has attracted considerable attention for its capacity to produce both fuelwood and foliage for either green manure or fodder. Its high content of proanthocyanidins (condensed tannins) and associated low digestibility has, however, limited its use as a feed for ruminants, and there is also a widespread perception that wilting the leaves further reduces their nutritive value. Nevertheless, there has been increasing uptake of calliandra as fodder in certain regions, notably the Central Highlands of Kenya. The present study, conducted in Embu, Kenya, investigated effects of provenance, wilting, cutting frequency and seasonal variation both in the laboratory (in vitro digestibility, crude protein, neutral detergent fibre, extractable and bound proanthocyanidins) and in on-station animal production trials with growing lambs and lactating goats. The local Kenyan landrace of calliandra (Embu) and a closely-related Guatemalan provenance (Patulul) were found to be significantly different, and superior, to a provenance from Nicaragua (San Ramón) in most of the laboratory traits measured, as well as in animal production and feed efficiency. Cutting frequency had no important effect on quality; and although all quality traits displayed seasonal variation there was little discernible pattern to this variation. Wilting had a much less negative effect than expected, and for lambs fed calliandra as a supplement to a low quality basal feed (maize stover), wilting was actually found to give higher live-weight gain and feed efficiency. Conversely, with a high quality basal diet (Napier grass) wilting enhanced intake but not live-weight gain, so feed efficiency was greater for fresh material. The difference between fresh and wilted leaves was not great enough to justify the current widespread recommendation that calliandra should always be fed fresh.

Infestations of post-smolt sea trout (Salmo trutta L.) by the salmon louse (Lepeophtheirus salmonis Krøyer) were characterized in 42 estuaries over a 5 year period in Ireland. Spatial variation in infestation was more significant than temporal trends and existed at 3 levels; between regions (regions >100 km of coastline), between bays within regions (bays <50 km in length) and between estuaries within bays (distance between estuaries <10 km). The observed spatial structure in infestations inferred that production of the infective larvae varied between regions and bays and that there was limited movement of fish and infective larvae between regions and bays. In addition the different levels of infestation recorded between estuaries in the same bay indicated short spatial scale variability in parasite transmission. Significantly higher infestations occurred in bays that contained lice-infested farmed salmon. Lice-infested wild spring salmon, which were present in estuaries of some systems, did not have a significant positive impact on infestations.

In recent years, we have developed rapid photothermal chemical vapor deposition (RPCVD) technique. In RPCVD, photons with wavelength between 100–400 nm irradiate the side of the substrate where chemical reactions take place. RPCVD provides materials with minimum microscopic defects and minimum thermal and residual stress. Due to these features and low processing time and low processing temperature capabilities, RPCVD is ideal for process integration and manufacturibility. In this paper we have presented the results of high K and low K dielectrics. Detailed electrical, structural, characterization, and stress measurements combined with reliability of data indicate that RPCVD has the potential of meeting advanced manufacturing needs of semiconductor and other related industries.

Thin Al films alloyed with three different compositions (0.1%, 1%, 5% by weight) of Yttrium were deposited by D.C. Magnetron Sputtering onto oxidized Si wafer substrates. The samples were furnace annealed at 425 °C for 30 minutes. Resistivity measured for the as-deposited and annealed Al(0. lwt% Y) were 3.07 and 2.57+/−0.25 μΩcm respectively. Al(0. lwt% Y) was also annealed by furnace annealing (FA), rapid thermal annealing (RTA) and rapid photothermal annealing (RPA). RPA gave a residual resistivity of 2.67μΩcm in 5 minutes and at a temperature of 350 C for Al(0. lwt% Y). Mean time to failure for AI(0. lwt% Y) samples at a current density of 3.2+/−0.5×106A/cm2 at 30 C was 50 hours. TEM results showed grain size variation from 0.5 to 2 μm.