211 research outputs found
Sperm competition shapes gene expression and sequence evolution in the ocellated wrasse.
Gene expression differences between males and females often underlie sexually dimorphic phenotypes, and the expression levels of genes that are differentially expressed between the sexes are thought to respond to sexual selection. Most studies on the transcriptomic response to sexual selection treat sexual selection as a single force, but postmating sexual selection in particular is expected to specifically target gonadal tissue. The three male morphs of the ocellated wrasse (Symphodus ocellatus) make it possible to test the role of postmating sexual selection in shaping the gonadal transcriptome. Nesting males hold territories and have the highest reproductive success, yet we detected feminization of their gonadal gene expression compared to satellite males. Satellite males are less brightly coloured and experience more intense sperm competition than nesting males. In line with postmating sexual selection affecting gonadal gene expression, we detected a more masculinized expression profile in satellites. Sneakers are the lowest quality males and showed both de-masculinization and de-feminization of gene expression. We also detected higher rates of gene sequence evolution of male-biased genes compared to unbiased genes, which could at least in part be explained by positive selection. Together, these results reveal the potential for postmating sexual selection to drive higher rates of gene sequence evolution and shape the gonadal transcriptome profile
Does proximity to aquatic pollution impact reproductive traits in a wild-caught intertidal fish?
Changes in Serological Immunology Measures in UK and Kenyan Adults Post-controlled Human Malaria Infection.
Background: The timing of infection is closely determined in controlled human malaria infection (CHMI) studies, and as such they provide a unique opportunity to dissect changes in immunological responses before and after a single infection. The first Kenyan Challenge Study (KCS) (Pan African Clinical Trial Registry: PACTR20121100033272) was performed in 2013 with the aim of establishing the CHMI model in Kenya. This study used aseptic, cryopreserved, attenuated Plasmodium falciparum sporozoites administered by needle and syringe (PfSPZ Challenge) and was the first to evaluate parasite dynamics post-CHMI in individuals with varying degrees of prior exposure to malaria. Methods: We describe detailed serological and functional immunological responses pre- and post-CHMI for participants in the KCS and compare these with those from malaria-naïve UK volunteers who also underwent CHMI (VAC049) (ClinicalTrials.gov NCT01465048) using PfSPZ Challenge. We assessed antibody responses to three key blood-stage merozoite antigens [merozoite surface protein 1 (MSP1), apical membrane protein 1 (AMA1), and reticulocyte-binding protein homolog 5 (RH5)] and functional activity using two candidate measures of anti-merozoite immunity; the growth inhibition activity (GIA) assay and the antibody-dependent respiratory burst activity (ADRB) assay. Results:Clear serological differences were observed pre- and post-CHMI by ELISA between malaria-naïve UK volunteers in VAC049, and Kenyan volunteers who had prior malaria exposure. Antibodies to AMA1 and schizont extract correlated with parasite multiplication rate (PMR) post-CHMI in KCS. Serum from volunteer 110 in KCS, who demonstrated a dramatically reduced PMR in vivo, had no in vitro GIA prior to CHMI but the highest level of ADRB activity. A significant difference in ADRB activity was seen between KCS volunteers with minimal and definite prior exposure to malaria and significant increases were seen in ADRB activity post-CHMI in Kenyan volunteers. Quinine and atovaquone/proguanil, previously assumed to be removed by IgG purification, were identified as likely giving rise to aberrantly high in vitro GIA results. Conclusions: The ADRB activity assay is a promising functional assay that warrants further investigation as a measure of prior exposure to malaria and predictor of control of parasite growth. The CHMI model can be used to evaluate potential measures of naturally-acquired immunity to malaria
Clinician-rated quality of video otoscopy recordings and still images for the asynchronous assessment of middle-ear disease
INTRODUCTION : Video otoscopy plays an important role in improving access to ear health services. This study investigated the clinician-rated quality of video otoscopy recordings and still images, and compared their suitability for asynchronous diagnosis of middle-ear disease.
METHODS : Two hundred and eighty video otoscopy image–recording pairs were collected from 150 children (aged six months to 15 years) by an ear, nose, and throat (ENT) specialist, audiologists, and trained research assistants, and independently rated by an audiologist and ENT surgeon. On a five-point scale, clinicians rated the cerumen amount, field of view, quality, focus, light, and gave an overall rating, and asked whether they could make an accurate diagnosis for both still images and recordings.
RESULTS : More video otoscopy recordings were rated as ‘good’ or ‘excellent’ compared to still images across all domains. The mean difference between the two otoscopic procedures ratings was significant across almost all domains (p < 0.05), except ‘cerumen amount’. The suitability to make a diagnosis significantly improved when using recordings (p<0.05). Younger participant age was found to have a significant, negative impact on the ratings across all domains (p < 0.03). The role of the tester conducting video otoscopy did not have a significant impact on the ratings.
DISCUSSION : Video otoscopy recordings were found to provide clearer views of the tympanic membrane and increase the ability to make diagnoses, compared to still images, for both audiologists and ENT surgeons. Research assistants with limited practice were able to obtain video otoscopy images and recordings that were comparable to the ones obtained by clinicians.The Telethon Kids Institutehttps://journals.sagepub.com/home/jtthj2022Speech-Language Pathology and Audiolog
Clinician-rated quality of video otoscopy recordings and still images for the asynchronous assessment of middle-ear disease
INTRODUCTION : Video otoscopy plays an important role in improving access to ear health services. This study investigated the clinician-rated quality of video otoscopy recordings and still images, and compared their suitability for asynchronous diagnosis of middle-ear disease.
METHODS : Two hundred and eighty video otoscopy image–recording pairs were collected from 150 children (aged six months to 15 years) by an ear, nose, and throat (ENT) specialist, audiologists, and trained research assistants, and independently rated by an audiologist and ENT surgeon. On a five-point scale, clinicians rated the cerumen amount, field of view, quality, focus, light, and gave an overall rating, and asked whether they could make an accurate diagnosis for both still images and recordings.
RESULTS : More video otoscopy recordings were rated as ‘good’ or ‘excellent’ compared to still images across all domains. The mean difference between the two otoscopic procedures ratings was significant across almost all domains (p < 0.05), except ‘cerumen amount’. The suitability to make a diagnosis significantly improved when using recordings (p<0.05). Younger participant age was found to have a significant, negative impact on the ratings across all domains (p < 0.03). The role of the tester conducting video otoscopy did not have a significant impact on the ratings.
DISCUSSION : Video otoscopy recordings were found to provide clearer views of the tympanic membrane and increase the ability to make diagnoses, compared to still images, for both audiologists and ENT surgeons. Research assistants with limited practice were able to obtain video otoscopy images and recordings that were comparable to the ones obtained by clinicians.The Telethon Kids Institutehttps://journals.sagepub.com/home/jtthj2022Speech-Language Pathology and Audiolog
Study of the B^0 Semileptonic Decay Spectrum at the Upsilon(4S) Resonance
We have made a first measurement of the lepton momentum spectrum in a sample
of events enriched in neutral B's through a partial reconstruction of B0 -->
D*- l+ nu. This spectrum, measured with 2.38 fb**-1 of data collected at the
Upsilon(4S) resonance by the CLEO II detector, is compared directly to the
inclusive lepton spectrum from all Upsilon(4S) events in the same data set.
These two spectra are consistent with having the same shape above 1.5 GeV/c.
From the two spectra and two other CLEO measurements, we obtain the B0 and B+
semileptonic branching fractions, b0 and b+, their ratio, and the production
ratio f+-/f00 of B+ and B0 pairs at the Upsilon(4S). We report b+/b0=0.950
(+0.117-0.080) +- 0.091, b0 = (10.78 +- 0.60 +- 0.69)%, and b+ = (10.25 +- 0.57
+- 0.65)%. b+/b0 is equivalent to the ratio of charged to neutral B lifetimes,
tau+/tau0.Comment: 14 page, postscript file also available at
http://w4.lns.cornell.edu/public/CLN
Permafrost landscape history shapes fluvial chemistry, ecosystem carbon balance, and potential trajectories of future change
Intensifying permafrost thaw alters carbon cycling by mobilizing large amounts of terrestrial substrate into aquatic ecosystems. Yet, few studies have measured aquatic carbon fluxes and constrained drivers of ecosystem carbon balance across heterogeneous Arctic landscapes. Here, we characterized hydrochemical and landscape controls on fluvial carbon cycling, quantified fluvial carbon fluxes, and estimated fluvial contributions to ecosystem carbon balance across 33 watersheds in four ecoregions in the continuous permafrost zone of the western Canadian Arctic: unglaciated uplands, ice-rich moraine, and organic-rich lowlands and till plains. Major ions, stable isotopes, and carbon speciation and fluxes revealed patterns in carbon cycling across ecoregions defined by terrain relief and accumulation of organics. In previously unglaciated mountainous watersheds, bicarbonate dominated carbon export (70% of total) due to chemical weathering of bedrock. In lowland watersheds, where soil organic carbon stores were largest, lateral transport of dissolved organic carbon (50%) and efflux of biotic CO2 (25%) dominated. In watersheds affected by thaw-induced mass wasting, erosion of ice-rich tills enhanced chemical weathering and increased particulate carbon fluxes by two orders of magnitude. From an ecosystem carbon balance perspective, fluvial carbon export in watersheds not affected by thaw-induced wasting was, on average, equivalent to 6%–16% of estimated net ecosystem exchange (NEE). In watersheds affected by thaw-induced wasting, fluvial carbon export approached 60% of NEE. Because future intensification of thermokarst activity will amplify fluvial carbon export, determining the fate of carbon across diverse northern landscapes is a priority for constraining trajectories of permafrost region ecosystem carbon balance
Radiative Decay Modes of the Meson
Using data recorded by the CLEO-II detector at CESR we have searched for four
radiative decay modes of the meson: ,
, , and . We
obtain 90% CL upper limits on the branching ratios of these modes of , , and
respectively.Comment: 15 page postscript file, postscript file also available through
http://w4.lns.cornell.edu/public/CLN
Measurement of the Mass Splittings between the States
We present new measurements of photon energies and branching fractions for
the radiative transitions: Upsilon(2S)->gamma+chi_b(J=0,1,2). The masses of the
chi_b states are determined from the measured radiative photon energies. The
ratio of mass splittings between the chi_b substates,
r==(M[J=2]-M[J=1])/(M[J=1]-M[J=0]) with M the chi_b mass, provides information
on the nature of the bbbar confining potential. We find
r(1P)=0.54+/-0.02+/-0.02. This value is in conflict with the previous world
average, but more consistent with the theoretical expectation that r(1P)<r(2P);
i.e., that this mass splittings ratio is smaller for the chi_b(1P) triplet than
for the chi_b(2P) triplet.Comment: 11 page postscript file, postscript file also available through
http://w4.lns.cornell.edu/public/CLN
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