112 research outputs found
Impact of Cloud Longwave Scattering on Radiative Fluxes Associated With the MaddenâJulian Oscillation in the Indian Ocean and Maritime Continent
Previous studies suggested that cloud longwave radiation contributes to the development and maintenance of the MaddenâJulian Oscillation (MJO) and modelâbased convection is highly sensitive to the radiation scheme. However, currently used radiation schemes do not take cloud longwave scattering into account, resulting in an overestimation of the outgoing longwave radiation (OLR) and an underestimation of the downward longwave flux at the surface. We use combined active and passive satellite cloud property retrievals to quantify the oneâlayer cloud OLR and heating rate (HR) biases introduced by neglecting cloud longwave scattering in the Indian Ocean and Maritime Continent in the context of MJO, with a focus on its phases 3, 5, and 6. The results show that the satelliteâdetected oneâlayer cloud area consists primarily of ice clouds, particularly during the boreal winter in the 4âyear study period. An increased ice cloud area fraction of oneâlayer cloud groups is present up to 5Â days before the onset of MJO events. If longwave scattering is neglected, the composite mean OLR overestimation over the oneâlayer ice cloud area from 5Â days before to 4Â days after the MJO passage is approximately 3.5 to 5.0Â WÂ mâ2. Neglecting longwave scattering also leads to a HR underestimation at cloud base and an overestimation at cloud top, making the baseâtoâtop heating gradient less sharp at the cloudâresolving scale.Key PointsDuration of oneâlayer ice cloud coverage increases up to 5Â days before the MaddenâJulian Oscillation (MJO) passageNeglecting longwave scattering leads to a 3.5 to 5.0Â WÂ mâ2 overestimation of the outgoing longwave radiation (OLR)Neglecting longwave scattering leads to a less sharp heating gradient from cloud base to cloud topPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155944/1/jgrd56305_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155944/2/jgrd56305.pd
Secretory Phase and Implantation
This chapter will explore the latter phase of the menstrual cycle focusing on the secretory phase of the endometrium. In particular, focus will be on the mid-secretory endometrium and appropriate markers and hormonal environment for successful implantation. This will be put in the context of the luteal phase of ovulation and the hormonal support that progesterone provides. We will also review pathologic states, such as endometriosis and related progesterone resistance, which affect mid-secretory phase and implantation. Finally, we will provide a detailed review of the literature on what the current state of knowledge is regarding receptivity and the microenvironment of the mid-secretory endometrium which is essential to implantation
Leveraging Automated Image Analysis Tools to Transform Our Capacity to Assess Status and Trends of Coral Reefs
Digital photography is widely used by coral reef monitoring programs to assess benthic status and trends. In addition to creating a permanent archive, photographic surveys can be rapidly conducted, which is important in environments where bottom-time is frequently limiting. However, substantial effort is required to manually analyze benthic images; which is expensive and leads to lags before data are available. Using previously analyzed imagery from NOAAâs Pacific Reef Assessment and Monitoring Program, we assessed the capacity of a trained and widely used machine-learning image analysis tool â CoralNet coralnet.ucsd.edu â to generate fully-automated benthic cover estimates for the main Hawaiian Islands (MHI) and American Samoa. CoralNet was able to generate estimates of site-level coral cover for both regions that were highly comparable to those generated by human analysts (Pearsonâs r > 0.97, and with bias of 1% or less). CoralNet was generally effective at estimating cover of common coral genera (Pearsonâs r > 0.92 and with bias of 2% or less in 6 of 7 cases), but performance was mixed for other groups including algal categories, although generally better for American Samoa than MHI. CoralNet performance was improved by simplifying the classification scheme from genus to functional group and by training within habitat types, i.e., separately for coral-rich, pavement, boulder, or âotherâ habitats. The close match between human-generated and CoralNet-generated estimates of coral cover pooled to the scale of island and year demonstrates that CoralNet is capable of generating data suitable for assessing spatial and temporal patterns. The imagery we used was gathered from sites randomly located in <30 m hard-bottom at multiple islands and habitat-types per region, suggesting our results are likely to be widely applicable. As image acquisition is relatively straightforward, the capacity of fully-automated image analysis tools to minimize the need for resource intensive human analysts opens possibilities for enormous increases in the quantity and consistency of coral reef benthic data that could become available to researchers and managers
First search for long-duration transient gravitational waves after glitches in the Vela and Crab pulsars
Gravitational waves (GWs) can offer a novel window into the structure and
dynamics of neutron stars. Here we present the first search for long-duration
quasi-monochromatic GW transients triggered by pulsar glitches. We focus on two
glitches observed in radio timing of the Vela pulsar (PSR J0835-4510) on 12
December 2016 and the Crab pulsar (PSR J0534+2200) on 27 March 2017, during the
Advanced LIGO second observing run (O2). We assume the GW frequency lies within
a narrow band around twice the spin frequency as known from radio observatons.
Using the fully-coherent transient-enabled F-statistic method to search for
transients of up to four months in length. We find no credible GW candidates
for either target, and through simulated signal injections we set 90% upper
limits on (constant) GW strain as a function of transient duration. For the
larger Vela glitch, we come close to beating an indirect upper limit for when
the total energy liberated in the glitch would be emitted as GWs, thus
demonstrating that similar post-glitch searches at improved detector
sensitivity can soon yield physical constraints on glitch models.Comment: 10 pages, 3 figures (incl. appendices). Updated to match version
accepted by PRD and fixed a few reference
Large-Scale Vertical Velocity, Diabatic Heating and Drying Profiles Associated with Seasonal and Diurnal Variations of Convective Systems Observed in the GoAmazon2014/5 Experiment
This study describes the characteristics of large-scale vertical velocity,
apparent heating source (Q1) and apparent moisture sink
(Q2) profiles associated with seasonal and diurnal variations
of convective systems observed during the two intensive operational periods
(IOPs) that were conducted from 15 February to 26 March 2014 (wet season) and
from 1 September to 10 October 2014 (dry season) near Manaus, Brazil, during
the Green Ocean Amazon (GoAmazon2014/5) experiment. The derived large-scale
fields have large diurnal variations according to convective activity in the
GoAmazon region and the morning profiles show distinct differences between
the dry and wet seasons. In the wet season, propagating convective systems
originating far from the GoAmazon region are often seen in the early morning,
while in the dry season they are rarely observed. Afternoon convective
systems due to solar heating are frequently seen in both seasons.
Accordingly, in the morning, there is strong upward motion and associated
heating and drying throughout the entire troposphere in the wet season, which
is limited to lower levels in the dry season. In the afternoon, both seasons\ud
exhibit weak heating and strong moistening in the boundary layer related to
the vertical convergence of eddy fluxes. A set of case studies of three
typical types of convective systems occurring in Amazonia â i.e.,
locally occurring systems, coastal-occurring systems and basin-occurring
systems â is also conducted to investigate the variability of the
large-scale environment with different types of convective systems
Proportions of Convective and Stratiform Precipitation Revealed in Water Isotope Ratios
Tropical and midlatitude precipitation is fundamentally of two types, spatially-limited and high-intensity convective or widespread and lower-intensity stratiform, owing to differences in vertical air motions and microphysical processes governing rain formation. These processes are difficult to observe or model and precipitation partitioning into rain types is critical for understanding how the water cycle responds to climate changes. Here, we combine two independent data sets â convective and stratiform precipitation fractions, derived from the Tropical Rainfall Measuring Mission satellite or synoptic cloud observations, and stable isotope and tritium compositions of surface precipitation, derived from a global network â to show that isotope ratios reflect rain type proportions and are negatively correlated with stratiform fractions. Condensation and riming associated with boundary layer moisture produces higher isotope ratios in convective rain, along with higher tritium when riming in deep convection occurs with entrained air at higher altitudes. Based on our data, stable isotope ratios can be used to monitor changes in the character of precipitation in response to periodic variability or changes in climate. Our results also provide observational constraints for an improved simulation of convection in climate models and a better understanding of isotope variations in proxy archives, such as speleothems and tropical ice
Exploiting antitumor immunity to overcome relapse and improve remission duration
Cancer survivors often relapse due to evolving drug-resistant clones and repopulating tumor stem cells. Our preclinical study demonstrated that terminal cancer patientâs lymphocytes can be converted from tolerant bystanders in vivo into effective cytotoxic T-lymphocytes in vitro killing patientâs own tumor cells containing drug-resistant clones and tumor stem cells. We designed a clinical trial combining peginterferon α-2b with imatinib for treatment of stage III/IV gastrointestinal stromal tumor (GIST) with the rational that peginterferon α-2b serves as danger signals to promote antitumor immunity while imatinibâs effective tumor killing undermines tumor-induced tolerance and supply tumor-specific antigens in vivo without leukopenia, thus allowing for proper dendritic cell and cytotoxic T-lymphocyte differentiation toward Th1 response. Interim analysis of eight patients demonstrated significant induction of IFN-Îł-producing-CD8+, -CD4+, -NK cell, and IFN-Îł-producing-tumor-infiltrating-lymphocytes, signifying significant Th1 response and NK cell activation. After a median follow-up of 3.6 years, complete response (CR) + partial response (PR) = 100%, overall survival = 100%, one patient died of unrelated illness while in remission, six of seven evaluable patients are either in continuing PR/CR (5 patients) or have progression-free survival (PFS, 1 patient) exceeding the upper limit of the 95% confidence level of the genotype-specific-PFS of the phase III imatinib-monotherapy (CALGB150105/SWOGS0033), demonstrating highly promising clinical outcomes. The current trial is closed in preparation for a larger future trial. We conclude that combination of targeted therapy and immunotherapy is safe and induced significant Th1 response and NK cell activation and demonstrated highly promising clinical efficacy in GIST, thus warranting development in other tumor types
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