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Microcredit – joint-liability loans to the poorest of the poor – has been touted as a powerful approach for combatting global poverty, but sustainability varies dramatically across banks. Efforts to improve the sustainability of microcredit have assumed defaults are caused by free-riding. Here, we point out that the response of other group members to delinquent groupmates also plays an important role in defaults. Even in the absence of any free-rider problem, some people will be unable to make their payments due to bad luck. It is other group members’ unwillingness to pitch in extra – due to, among other things, not wanting to have less than other group members – that leads to default. To support this argument, we utilize the Ultimatum Game (UG), a standard paradigm from behavioral economics for measuring one's aversion to inequitable outcomes. First, we show that country-level variation in microloan default rates is strongly correlated (overall r = 0.81) with country-level UG rejection rates, but not free-riding measures. We then introduce a laboratory model ‘Microloan Game’ and present evidence that defaults arise from inequity-averse individuals refusing to make up the difference when others fail to pay their fair share. This perspective suggests a suite of new approaches for combatting defaults that leverage findings on reducing UG rejections.
Field studies were conducted in 2016 and 2017 at Clinton, NC, to quantify the effects of season-long interference of large crabgrass [Digitaria sanguinalis (L.) Scop.] and Palmer amaranth (Amaranthus palmeri S. Watson) on ‘AG6536’ soybean [Glycine max (L.) Merr.]. Weed density treatments consisted of 0, 1, 2, 4, and 8 plants m−2 for A. palmeri and 0, 1, 2, 4, and 16 plants m−2 for D. sanguinalis with (interspecific interference) and without (intraspecific interference) soybean to determine the impacts on weed biomass, soybean biomass, and seed yield. Biomass per square meter increased with increasing weed density for both weed species with and without soybean present. Biomass per square meter of D. sanguinalis was 617% and 37% greater when grown without soybean than with soybean, for 1 and 16 plants m−2 respectively. Biomass per square meter of A. palmeri was 272% and 115% greater when grown without soybean than with soybean for 1 and 8 plants m−2, respectively. Biomass per plant for D. sanguinalis and A. palmeri grown without soybean was greatest at the 1 plant m−2 density. Biomass per plant of D. sanguinalis plants across measured densities was 33% to 83% greater when grown without soybean compared with biomass per plant when soybean was present for 1 and 16 plants m−2, respectively. Similarly, biomass per plant for A. palmeri was 56% to 74% greater when grown without soybean for 1 and 8 plants m−2, respectively. Biomass per plant of either weed species was not affected by weed density when grown with soybean due to interspecific competition with soybean. Yield loss for soybean grown with A. palmeri ranged from 14% to 37% for densities of 1 to 8 plants m−2, respectively, with a maximum yield loss estimate of 49%. Similarly, predicted loss for soybean grown with D. sanguinalis was 0 % to 37% for densities of 1 to 16 m−2 with a maximum yield loss estimate of 50%. Soybean biomass was not affected by weed species or density. Results from these studies indicate that A. palmeri is more competitive than D. sanguinalis at lower densities, but that similar yield loss can occur when densities greater than 4 plants m−2 of either weed are present.
We apply two methods to estimate the 21-cm bispectrum from data taken within the Epoch of Reionisation (EoR) project of the Murchison Widefield Array (MWA). Using data acquired with the Phase II compact array allows a direct bispectrum estimate to be undertaken on the multiple redundantly spaced triangles of antenna tiles, as well as an estimate based on data gridded to the uv-plane. The direct and gridded bispectrum estimators are applied to 21 h of high-band (167–197 MHz; z = 6.2–7.5) data from the 2016 and 2017 observing seasons. Analytic predictions for the bispectrum bias and variance for point-source foregrounds are derived. We compare the output of these approaches, the foreground contribution to the signal, and future prospects for measuring the bispectra with redundant and non-redundant arrays. We find that some triangle configurations yield bispectrum estimates that are consistent with the expected noise level after 10 h, while equilateral configurations are strongly foreground-dominated. Careful choice of triangle configurations may be made to reduce foreground bias that hinders power spectrum estimators, and the 21-cm bispectrum may be accessible in less time than the 21-cm power spectrum for some wave modes, with detections in hundreds of hours.
Much of suicide research focuses on suicide attempt (SA) survivors. Given that more than half of the suicide decedent population dies on their first attempt, this means a significant proportion of the population that dies by suicide is overlooked in research. Little is known about persons who die by suicide on their first attempt–and characterizing this understudied population may improve efforts to identify more individuals at risk for suicide.
Data were derived from the National Violent Death Reporting System, from 2005 to 2013. Suicide cases were included if they were 18–89 years old, with a known circumstance leading to their death based on law enforcement and/or medical examiner reports. Decedents with and without a history of SA were compared on demographic, clinical, and suicide characteristics, and circumstances that contributed to their suicide.
A total of 73 490 cases met criteria, and 57 920 (79%) died on their first SA. First attempt decedents were more likely to be male, married, African-American, and over 64. Demographic-adjusted models showed that first attempt decedents were more likely to use highly lethal methods, less likely to have a known mental health problem or to have disclosed their intent to others, and more likely to die in the context of physical health or criminal/legal problem.
First attempt suicide decedents are demographically different from decedents with a history of SA, are more likely to use lethal methods and are more likely to die in the context of specific stressful life circumstances.
Field studies were conducted in 2016 and 2017 in Clinton, NC, to determine the interspecific and intraspecific interference of Palmer amaranth (Amaranthus palmeri S. Watson) or large crabgrass [Digitaria sanguinalis (L.) Scop.] in ‘Covington’ sweetpotato [Ipomoea batatas (L.) Lam.]. Amaranthus palmeri and D. sanguinalis were established 1 d after sweetpotato transplanting and maintained season-long at 0, 1, 2, 4, 8 and 0, 1, 2, 4, 16 plants m−1 of row in the presence and absence of sweetpotato, respectively. Predicted yield loss for sweetpotato was 35% to 76% for D. sanguinalis at 1 to 16 plants m−1 of row and 50% to 79% for A. palmeri at 1 to 8 plants m−1 of row. Weed dry biomass per meter of row increased linearly with increasing weed density. Individual dry biomass of A. palmeri and D. sanguinalis was not affected by weed density when grown in the presence of sweetpotato. When grown without sweetpotato, individual weed dry biomass decreased 71% and 62% from 1 to 4 plants m−1 row for A. palmeri and D. sanguinalis, respectively. Individual weed dry biomass was not affected above 4 plants m−1 row to the highest densities of 8 and 16 plants m−1 row for A. palmeri and D. sanguinalis, respectively.
Architecture in England Remained a fledgling science until Inigo Jones's Italianate classicism burst forth in London in the first decades of the seventeenth century. His 1622 Banqueting House at Whitehall with its masterful double-cube interior astounded Londoners accustomed to the rabbit warren of Elizabethan apartments making up the surrounding Whitehall Palace; its rhythmic, subtly articulated marble façade clashed with the eclectic exteriors of neighboring buildings.
To investigate the effects of the nozzle-exit conditions on jet flow and sound fields, large-eddy simulations of an isothermal Mach 0.9 jet issued from a convergent-straight nozzle are performed at a diameter-based Reynolds number of
. The simulations feature near-wall adaptive mesh refinement, synthetic turbulence and wall modelling inside the nozzle. This leads to fully turbulent nozzle-exit boundary layers and results in significant improvements for the flow field and sound predictions compared with those obtained from the typical approach based on laminar flow in the nozzle. The far-field pressure spectra for the turbulent jet match companion experimental measurements, which use a boundary-layer trip to ensure a turbulent nozzle-exit boundary layer to within 0.5 dB for all relevant angles and frequencies. By contrast, the initially laminar jet results in greater high-frequency noise. For both initially laminar and turbulent jets, decomposition of the radiated noise into azimuthal Fourier modes is performed, and the results show similar azimuthal characteristics for the two jets. The axisymmetric mode is the dominant source of sound at the peak radiation angles and frequencies. The first three azimuthal modes recover more than 97 % of the total acoustic energy at these angles and more than 65 % (i.e. error less than 2 dB) for all angles. For the main azimuthal modes, linear stability analysis of the near-nozzle mean-velocity profiles is conducted in both jets. The analysis suggests that the differences in radiated noise between the initially laminar and turbulent jets are related to the differences in growth rate of the Kelvin–Helmholtz mode in the near-nozzle region.
OBJECTIVES/SPECIFIC AIMS: Gliomas are the most lethal and common
primary tumor type in the central nervous system across all age groups; affected
adults have a life expectancy of just 14 months. As glioma cells invade the
surrounding normal parenchyma they remodel the composition and ultrastructure of
the surrounding extracellular matrix (ECM), suggesting that the native (i.e.,
“normal”) microenvironment is not ideal for their survival
and proliferation. Recent reports describe suppressive and/or lethal
effects of mammalian ECM hydrogels derived from normal (nonneoplastic) sources
upon various cancer types. ECM-based bioscaffolds placed at sites of neoplastic
tissue resection in humans have never been reported to facilitate cancer
recurrence. The objective of the present research is to evaluate mammalian ECM
as a novel approach to glioma therapy. METHODS/STUDY POPULATION: ECM
hydrogels from porcine dermis, small intestine, and urinary bladder were
produced as described previously. Primary glioma cells were graciously supplied
by Drs. Nduka Amankulor and Johnathan Engh, and U-87 MG were ordered through
ATCC. Cells were plated onto tissue culture plastic at
~60% confluence and allowed to attach for 24 hours before
treatment. The saline-soluble fraction (SSF) of ECM was obtained by mixing
lyophilized, comminuted ECM with 0.9% saline for 24 hours then
filtering the resulting mixture through a 10 kDa molecular weight cutoff column.
All assays and kits were followed according to the manufacturer’s
instructions. Cell viability was measured via MTT assay
(Vybrant® MTT Cell Proliferation Assay, Invitrogen)
and by live/dead staining
(LIVE/DEAD® Cell Imaging Kit, Invitrogen). Time
lapse videos were created by taking images every 20 minutes for 18 hours
(phase-contrast) or every 10 minutes for 12 hours (darkfield). NucView reagent
was ordered from Biotium. Temozolomide was ordered through Abmole. All in vivo
work was conducted according to protocols approved by the University of
Pittsburgh’s IACUC office. RESULTS/ANTICIPATED RESULTS:
ECM hydrogels derived from porcine dermis, small intestine, or urinary bladder
all decreased the viability of primary glioma cells in vitro, with urinary
bladder extracellular matrix (UBM) having the most dramatic effects. The SSF of
UBM (UBM-SSF), devoid of the fibrillar, macromolecular components of ECM, was
sufficient to recapitulate this detrimental effect upon neoplastic cells in
vitro and was used for the remainder of the experiments described herein. In a
cell viability assay normalized to the media treatment, non-neoplastic CHME5 and
N1E-115 cells scored 103% and 114% after 48 hours when
treated with UBM-SSF and 2 primary high-grade glioma cell types scored
17% and 30.5% with UBM-SSF (n=2).
Phase-contrast time-lapse video showed CHME5 and HFF thriving in the presence of
UBM-SSF for 18 hours while most primary glioma cells shriveled and died within
this time. Darkfield time-lapse video of wells containing Nucview dye,
fluorescent upon cleavage by active caspase-3, confirmed that within 12 hours
most primary glioma cells underwent apoptosis while CHME5 and HFF did not. In
culture with primary astrocytes, high grade primary glioma cells, and U-87 MG
glioma cells for 24 hours, UBM-SSF was found to significantly increase the
population of primary astrocytes compared with media
(p<0.05) while decreasing the 2 glioma cell types to
approximately one-third as many cells as the media control
(p<0.0001). A dose-response of temozolomide from 0
to 10,000 μM showed that when treating 2 non-neoplastic cell types
(CHME5 and HFF) and 2 types of primary glioma cell there was no difference in
survivability at any concentration. Contrasted to this, a dose-response of
UBM-SSF from 350 to 7000 μg/mL showed that the
non-neoplastic cells survived significantly better than the glioma cells at
concentrations of 875 μg/mL and upward
(p<0.05). In preliminary animal experiments, large
primary glioma tumors in the flanks of athymic nude mice were resected and
replaced with either UBM SSF or Matrigel (an ECM product of neoplastic cell
origin). After 7 days the resection sites with UBM-SSF had little tumor regrowth
if any compared with the dramatic recurrence seen in the Matrigel injection
sites (n=2). In a separate survival study comparing PBS to UBM-SSF
injections in the flank-resection model, all animals given PBS had to be
sacrificed at 9, 11, and 11 days (n=3) whereas animals given UBM-SSF
were sacrificed at 15, 24, and 39 days (n=3), indicating a moderate
increase in survival due to the UBM-SSF. DISCUSSION/SIGNIFICANCE OF
IMPACT: Since the introduction of the pan-cytotoxic chemotherapeutic agent TMZ
in 2005, the standard of care for patients with glioblastoma multiforme has not
improved. These findings indicate that non-neoplastic ECM contains potent
bioactive regulators capable of abrogating malignancy. Our in vitro data suggest
these molecules appear to have no deleterious effect on non-neoplastic cells
while specifically inducing apoptosis in glioma cells. Our in vivo data suggest
that these molecules may be useful in delaying glioma recurrence, thus resulting
in extended lifespan. Delivering soluble fractions of ECM to a tumor site may
represent a novel approach to glioma therapy, sidestepping traditional cytotoxic
therapies in favor of utilizing putative endogenous anti-tumor pathways.
be an elliptic curve over a field
. There is a functor
from the category of finitely presented torsion-free left
-modules to the category of abelian varieties isogenous to a power of
, and a functor
in the opposite direction. We prove necessary and sufficient conditions on
for these functors to be equivalences of categories. We also prove a partial generalization in which
is replaced by a suitable higher-dimensional abelian variety over
This paper summarises developments in understanding sea level change during the Quaternary in Scotland since the publication of the Quaternary of Scotland Geological Conservation Review volume in 1993. We present a review of progress in methodology, particularly in the study of sediments in isolation basins and estuaries as well as in techniques in the field and laboratory, which have together disclosed greater detail in the record of relative sea level (RSL) change than was available in 1993. However, progress in determining the record of RSL change varies in different areas. Studies of sediments and stratigraphy offshore on the continental shelf have increased greatly, but the record of RSL change there remains patchy. Studies onshore have resulted in improvements in the knowledge of rock shorelines, including the processes by which they are formed, but much remains to be understood. Studies of Late Devensian and Holocene RSLs around present coasts have improved knowledge of both the extent and age range of the evidence. The record of RSL change on the W and NW coasts has disclosed a much longer dated RSL record than was available before 1993, possibly with evidence of Meltwater Pulse 1A, while studies in estuaries on the E and SW coasts have disclosed widespread and consistent fluctuations in Holocene RSLs. Evidence for the meltwater pulse associated with the Early Holocene discharge of Lakes Agassiz–Ojibway in N America has been found on both E and W coasts. The effects of the impact of storminess, in particular in cliff-top storm deposits, have been widely identified. Further information on the Holocene Storegga Slide tsunami has enabled a better understanding of the event, but evidence for other tsunami events on Scottish coasts remains uncertain. Methodological developments have led to new reconstructions of RSL change for the last 2000 years, utilising state-of-the-art GIA models and alongside coastal biostratigraphy to determine trends to compare with modern tide gauge and documentary evidence. Developments in GIA modelling have provided valuable information on patterns of land uplift during and following deglaciation. The studies undertaken raise a number of research questions which will require addressing in future work.
In a population with prior exposure to the World Trade Center (WTC) disaster, this study sought to determine the relationship between Hurricane Sandy-related inhalation exposures and post-Sandy lower respiratory symptoms (LRS).
Participants included 3835 WTC Health Registry enrollees who completed Wave 3 (2011-2012) and Hurricane Sandy (2013) surveys. The Sandy-related inhalational exposures examined were: (1) reconstruction exposure; (2) mold or damp environment exposure; and (3) other respiratory irritants exposure. LRS were defined as wheezing, persistent cough, or shortness of breath reported on ≥1 of the 30 days preceding survey completion. Associations between LRS and Sandy exposures, controlling for socio-demographic factors, post-traumatic stress disorder, and previously reported LRS and asthma were examined using multiple logistic regression.
Over one-third of participants (34.4%) reported post-Sandy LRS. Each of the individual exposures was also independently associated with post-Sandy LRS, each having approximately twice the odds of having post-Sandy LRS. We found a dose-response relationship between the number of types of Sandy-related exposures reported and post-Sandy LRS.
This study provides evidence that post-hurricane clean-up and reconstruction exposures can increase the risk for LRS. Public health interventions should emphasize the importance of safe remediation practices and recommend use of personal protective equipment. (Disaster Med Public Health Preparedness. 2018;12:697-702)
Neisseria meningitidis is a gram-negative bacterium that lives as a commensal in the human nasopharynx. Meningococci are generally non-invasive, but can invade the nasopharyngeal epithelia and enter the bloodstream causing life-threatening illnesses. It is generally thought that meningococci do not survive for long outside the host, and that transmission requires relatively close contact between hosts. There are some reports, however, that meningococci can survive drying on surfaces, including glass, plastic and cloth. Our examination of N. meningitidis strains dried on glass showed differences in survival of isolates belonging to serogroups B, C and W135, including persistence of Cuban, New Zealand, and Norwegian epidemic strains up to 8 days, depending on temperature and humidity. Survival of a New Zealand epidemic strain isolate NZ98/254 under ambient conditions in the laboratory was greatest in winter suggesting that environmental factors impacted survival. For most isolates, including NZ98/254, survival under controlled conditions at 30 °C was greater at 22% than 30% relative humidity. There were also some differences in survival between carriage and invasive strains. The results suggest that N. meningitidis could be transmitted through contact with surfaces outside the host, potentially including contact through shared drinking vessels.
Habitat preferences and response to habitat conversion remain under-studied for many groups in the tropics, limiting our understanding of how environmental and anthropogenic factors may interact to shape patterns of diversity. To help fill this knowledge gap, we surveyed nocturnal birds such as owls, nightjars and potoos through auditory transect surveys in 22 forest fragments (2.7 to 33.6 ha) in north-west Ecuador. We assessed the relative effect of habitat characteristics (e.g. canopy height and openness, and density of large trees) and fragment attributes (e.g. area, altitude and proportion of surrounding forest cover) on species richness and community composition. Based on our previous work, we predicted that nocturnal bird richness would be highest in relatively larger fragments with more surrounding forest cover. We recorded 11 total species with an average ± SD of 3.4 ± 1.4 (range = 2–7) species per fragment, with higher richness in fragments that were larger, at lower altitudes, and characterized by more open canopies. Nocturnal bird community similarity was not significantly correlated with any measured environmental variable. These results indicate that both landscape (e.g. altitude) and fragment-specific (e.g. size, forest structure) attributes are likely to interact to shape patterns of diversity among this poorly known but ecologically important guild in fragmented tropical landscapes.
This paper looks at how to measure the tradeoffs in monetary terms that the public is prepared to make with respect to adoption of different community policing options. The approach advanced is a discrete choice experiment in which survey respondents face different policing options which can be described by a set of attributes ranging from costs to outcomes. The main contribution of this paper is to show how to go beyond the usual characterization of the monetized benefits of reducing the level of a specific type of crime to asking the question of whether those benefits differ depending on how that outcome is achieved.
We review an improved statistical model of extra-galactic point-source foregrounds first introduced in Murray et al. (2017), in the context of the Epoch of Reionization. This model extends the instrumentally-convolved foreground covariance used in inverse-covariance foreground mitigation schemes, by considering the cosmological clustering of the sources. In this short work, we show that over scales of k ∼ (0.6, 40.)hMpc−1, ignoring source clustering is a valid approximation. This is in contrast to Murray et al. (2017), who found a possibility of false detection if the clustering was ignored. The dominant cause for this change is the introduction of a Galactic synchrotron component which shadows the clustering of sources.
Wavepackets obtained as solutions of the flow equations linearised around the mean flow have been shown in recent work to yield good agreement, in terms of amplitude and phase, with those educed from turbulent jets. Compelling agreement has been demonstrated, for the axisymmetric and first helical mode, up to Strouhal numbers close to unity. We here extend the range of validity of wavepacket models to Strouhal number
and azimuthal wavenumber
by comparing solutions of the parabolised stability equations with a well-validated large-eddy simulation of a Mach 0.9 turbulent jet. The results show that the near-nozzle dynamics can be correctly described by the homogeneous linear model, the initial growth rates being accurately predicted for the entire range of frequencies and azimuthal wavenumbers considered. Similarly to the lower-frequency wavepackets reported prior to this work, the high-frequency linear waves deviate from the data downstream of their stabilisation locations, which move progressively upstream as the frequency increases.
Preston et al (1976) and Burke (1982, these proceedings) have long extolled the virtues of launching a radio telescope into space to increase VLBI baseline lengths and thus angular resolution, and to provide a much enhanced image formation capability. The scientific motivation for this has been covered in a number of memoranda referenced by Burke in these proceedings, and by Anderson et al (1982). Efforts to mobilise western astronomical support for space VLBI met with success in late 1982 at a meeting of US and European radio astronomers in Toulouse, France, at which a decision was taken to propose a joint mission to ESA and NASA. Shortly thereafter, a formal proposal was made to ESA (Anderson et al 1982) for a free flying satellite in an elliptical orbit out to 15000 km from the Earth, designed to observe in concert with the major ground-based VLBI networks and arrays. The mission, dubbed QUASAT, was received favourably in both ESA and NASA, with the result that formal Assessment Studies are scheduled to begin in both agencies in October 1983.
An antenna in geostationary orbit was used for VLBI observations at 2.3 GHz, in combination with ground antennas in Australia and Japan. 23 of the 25 observed sources were detected on orbiter-ground baselines, with baseline lengths as large as 2.15 earth diameters. Brightness temperatures between 1012 K and 4 × 1012 K were measured for 10 sources.