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Topic choice is a previously unappreciated contributor to the lower rate of NIH awards to AA/B scientists., Despite efforts to promote diversity in the biomedical workforce, there remains a lower rate of funding of National Institutes of Health R01 applications submitted by African-American/black (AA/B) scientists relative to white scientists. To identify underlying causes of this funding gap, we analyzed six stages of the application process from 2011 to 2015 and found that disparate outcomes arise at three of the six: decision to discuss, impact score assignment, and a previously unstudied stage, topic choice. Notably, AA/B applicants tend to propose research on topics with lower award rates. These topics include research at the community and population level, as opposed to more fundamental and mechanistic investigations; the latter tend to have higher award rates. Topic choice alone accounts for over 20% of the funding gap after controlling for multiple variables, including the applicant’s prior achievements. Our findings can be used to inform interventions designed to close the funding gap.

Located within the tropics, Hong Kong has diverse marine habitats which host a rich marine biodiversity (∼6000 known species). Its marine environment is, however, under considerable anthropogenic pressure and continuous deterioration from rapid population growth and constant coastal development. This review summarizes the present status of the marine environment of Hong Kong from the perspectives of habitat loss and fragmentation, pollution, biological invasion, over-exploitation and climate change, which are the major threats identified by the IUCN to marine ecosystems. The Chinese white dolphin population (Sousa chinensis; one of the two resident marine mammals in Hong Kong) is at a historic low and continues to decline due to habitat loss through land reclamation, pollution, and intense marine traffic. Much of Hong Kong’s coastal water is degraded by both substantial local and transboundary pollution from the Pearl River Delta, leading to eutrophication and harmful algal blooms. Exposure risk to introduced exotic species is high, as Hong Kong is both the fourth busiest harbour in the world and release of animals into the marine environment during religious ceremonies is a common practice of local Buddhists and Taoists. The high consumption of seafood has stressed fishery stocks in Hong Kong and its supplying countries. All these impacts are compounded by the often insidious, but pressing, challenges of climate change, with warming temperatures and increasing acidity of coastal waters. Given these known and emerging threats, Hong Kong serves as a living laboratory to investigate the impacts of both global and local activities and, where possible, develop solutions which could be implemented globally.

Trawl bans are relatively uncommon, particularly at the level of an entire coastal jurisdiction, and have seldom been studied in the tropics. A permanent territory-wide trawl ban has been implemented in Hong Kong coastal waters since the beginning of 2013. We used isotope-based metrics, in addition to traditional community measurements, to determine whether benthic crustacean assemblages had shown any signs of recovery three years after the trawl ban. We expected increases in species richness, abundance and biomass as well as shifts in trophic structure, including longer food-chain length (FCL) and greater trophic diversity after the ban. We further anticipated that carnivorous crustaceans would have higher mean trophic positions (MTPoC) at the assemblage level, and broader trophic niches at the species level. Sampling was undertaken at six sites in three regions (eastern, western and southern waters) before (in 2012) and after (in 2015) the ban. In general, there were no changes in assemblage total abundance or species richness after the trawl ban, but a decrease in biomass was observed. Isotope-based metrics showed that trophic niches of the crustacean assemblages were, however, broader at all sites after the ban. The FCLs at four sites in the eastern and western waters were longer after the ban, and three of them also showed increased MTPoC. In contrast, declines in FCL and other trophic metrics were recorded at the two southern sites. Among the five most abundant carnivorous crustaceans, all species at one eastern site, three at one western site, and four at three other sites expanded their trophic niches after the trawl ban; no changes were evident at the other eastern site where carnivores were scarce. By using isotope-based trophic metrics, we detected early functional recovery of the crustacean assemblages that cannot be revealed by traditional community analyses, implying that the effectiveness of the trawl ban would be underestimated if the assessment was based on community measurements only. We, therefore, advocate the use of isotope-based trophic metrics in tandem with the community measurements for more comprehensive assessments of ecosystem responses to anthropogenic disturbances and management interventions designed to alleviate them.

Measures (e.g. δ15N, δ13C, %C, %N and C:N) derived from animal tissues are commonly used to estimate diets and trophic interactions. Since tissue samples are often exposed to air or kept chilled in ice over a short-term during sample preparation, they may degrade. Herein, we hypothesize that tissue decomposition will cause changes in these measures. In this study, we kept marine fish, crustacean and mollusc tissues in air or ice over 120 h (5 days). We found that tissue decomposition in air enriched δ15N (range 0.6‰ to 1.3‰) and δ13C (0.2‰ to 0.4‰), decreased %N (0.47 to 3.43 percentage points from staring values of ~13%) and %C (4.53 to 8.29 percentage points from starting values of ~43%), and subsequently increased C:N ratio (0.14 to 0.75). In air, while such changes to δ13C were relatively minor and therefore likely tolerable, changes in δ15N, %N, %C and C:N ratio should be interpreted with caution. Ice effectively reduced the extent to which decomposition enriched δ15N (≤ 0.4‰) and δ13C (≤ 0.2‰), and eliminated decomposition in C:N ratio, %N and %C. In our second experiment, for fish tissues in either air or ice over 120 h, we observed no effects of decomposition on relationships between lipid content, C:N ratio, and Δδ13C (change in δ13C after lipid removal), which are employed to correct δ13C for samples containing lipid. We also confirmed that lipid in tissues caused large errors when estimating δ13C (mean ± standard error = -1.8‰ ± 0.1‰, range -0.6‰ to -3.8‰), and showed both lipid extraction and mathematical correction performed equally well to correct for lipids when estimating δ13C. We, therefore, recommend that specimens of marine animals should be kept in ice during sample preparation for a short-term, as it is an effective means for minimizing changes of the stable isotope measures in their tissue.

Globally, coastlines are under pressure as coastal human population growth and urbanization continues, while climatic change leads to stormier seas and rising tides. These trends create a strong and sustained demand for land reclamation and infrastructure protection in coastal areas, requiring engineered coastal defence structures such as sea walls. Here, we review the nature of ecological impacts of coastal structures on intertidal ecosystems, seek to understand the extent to which ecological engineering can mitigate these impacts, and evaluate the effectiveness of mitigation as a tool to contribute to conservation of intertidal habitats. By so doing, we identify critical knowledge gaps to inform future research. Coastal structures alter important physical, chemical and biological processes of intertidal habitats, and strongly impact community structure, inter-habitat linkages and ecosystem services while also driving habitat loss. Such impacts occur diffusely across localised sites but scale to significant regional and global levels. Recent advances in ecological engineering have focused on developing habitat complexity on coastal structures to increase biodiversity. ‘Soft’ engineering options maximise habitat complexity through inclusion of natural materials, species and processes, while simultaneously delivering engineering objectives such as coastal protection. Soft options additionally sustain multiple services, providing greater economic benefits for society, and resilience to climatic change. Currently however, a lack of inclusion and economic undervaluation of intertidal ecosystem services may undermine best practice in coastline management. Importantly, reviewed evidence shows mitigation and even restoration do not support intertidal communities or processes equivalent to pre-disturbance conditions. Crucially, an absence of comprehensive empirical baseline biodiversity data, or data comprising additional ecological parameters such as ecosystem functions and services, prohibits quantification of absolute and relative magnitudes of ecological impacts due to coastal structures or effectiveness of mitigation interventions. This knowledge deficit restricts evaluation of the potential of ecological engineering to contribute to conservation policies for intertidal habitats. To improve mitigation design and effectiveness, a greater focus on in-situ research is needed, requiring stronger and timely collaboration between government agencies, construction partners and research scientists.

Background Posttreatment control of HIV infection is a rare phenomenon primarily described among those initiating treatment with antiretroviral therapy (ART) during early/acute HIV infection. Methods We examined a large, well-characterized cohort of HIV-infected Department of Defense beneficiaries for the presence of posttreatment controllers (PTCs) whom we defined as individuals with sustained viral suppression for ≥6 months after discontinuation of ART. We defined those who became viremic within 6 months of discontinuing ART as rapid viremics (RVs) and compared demographic and clinical characteristics, CD4 counts, and viral loads prior, during, and after ART discontinuation between the 2 groups. Results From a cohort of 6070 patients, we identified 95 who had been treated with ART for 2 years or more who subsequently discontinued ART and had viral load assessments available after discontinuation. Four (4.2%) of these 95 met our definition of PTC. The duration of viral suppression off of ART ranged from 267 to 1058 days with 1 of the 4 restarting ART without having redeveloped a significant viremia. All 4 patients initiated ART during chronic HIV infection. Demographic and clinical characteristics of PTCs were similar to RVs. Conclusions While posttreatment control has predominantly been described among individuals who initiated ART in early/acute HIV infection, we identified 4 PTCs who started ART during chronic infection suggesting that posttreatment control also occurs among such patients. The rarity of PTCs identified in our cohort is consistent with reports from previous studies.

We report a case of successful treatment of chronic osteomyelitis (emanating from contaminated soil exposure) caused by Clostridium sphenoides, an organism infrequently identified as a cause of human infection and more saliently osteomyelitis (only 1 reported case in the literature). Additional impetus for reporting this case resides in the insights gained regarding pathogen identification exploiting sophisticated molecular platforms coupled to traditional microbial culture-based methods. The fastidious nature of cultivating anaerobic organisms required initial attempts at 16S rRNA sequencing to identify a Clostridium species (Clostridium celerecrescens). However, on exploiting matrix-assisted laser desorption ionization time of flight (MALDI TOF) technology, C. sphenoides was identified, and confirmed on whole genome sequencing. The discrepancies noted in the varying platforms require vigilance to seek complementary testing for conflicting results. Although highly accurate, the MALDI TOF and 16S rRNA sequencing platforms are not immune to false identification particularly in differentiating closely related organisms. More germane, whole genome sequencing should be entertained when conflicting results are obtained from MALDI TOF and 16S rRNA sequencing. Precise species and/or strain level identification can be clinically relevant as antimicrobial sensitivity profiles may be discrepant between closely related species influencing clinical outcomes. Thus, it is incumbent on us to strive to acquire the correct species characterization when resources allow to dictate optimal treatment.

With over 200,000 cases in the U.S. each year, urethritis represents a common condition seen by both primary care providers and sexually transmitted diseases (STD) clinics. Urethritis is urethral inflammation and historically, the term urethritis was reserved for patients with urethral discharge. However, other symptoms can occur in menwithout discharge such as penile itching and/or dysuria. A diagnosis can be made if at least one of the following is present: a discharge, a positive leukocyte esterase test on first void urine, or at least 10 white blood cells per high power filed in urine sediment. Traditionally, urethritis has been classified as gonococcal or non-gonococcal (NGU) based on the Gram staining of urethral discharge for Gramnegative diplococci. A significant proportion of NGU cases are caused by Chlamydia trachomatis. Please see the chapter on chlamydial infections for a full discussion on this pathogen. Although C. trachomatis is a common cause of NGU, accounting for 20–30% of cases with more than three times as many cases reported than gonorrhea, the majority of cases are caused by other pathogens. Urethritis cases where gonorrhea and chlamydia have been ruled out have presented both a diagnostic and a treatment challenge for the clinician. Recent studies have focused on identifying causes of non-gonococcal urethritis and developing testing or atypical organisms such as Mycoplasma genitalium. and Ureaplasma species. In recent years the role of M. genitalium, as etiologic agents of NGU has been better elucidated. Multiple bacterial and viral pathogens along with noninfectious processes are now known to cause urethritis. The risk for acquisition of certain pathogens leading to the development of NGU has been linked to specific sexual behaviors and local prevalence of certain STDs. As with gonococcal infection, the development of antibiotic resistance is a concern when treating NGU cases due to M. genitalium.

Increasing concern over the loss of biodiversity has led to attempts to quantify relationships between biodiversity and ecosystem functioning. While manipulative investigations have accumulated substantial evidence to support the notion that decreasing biodiversity can be detrimental to the functioning of ecosystems, recent investigations have identified the potential importance of physical processes in moderating biodiversity - ecosystem function relationships at larger geographical scales. In this study, the relationship between the genus richness of benthic macro-invertebrates and five measures of ecosystem functioning (macrofaunal biomass, depth of the apparent redox discontinuity, fluxes of ammonium and NO x and the abundance of nematodes) was determined over a large scale wave-induced bed shear stress gradient on the seabed of the northern Irish Sea. Ecosystem functioning was significantly correlated to genus richness for four out of five ecosystem functions. However, wave stress moderated the genus richness - ecosystem functioning relationship for only one of the ecosystem functions; genus richness had a positive effect on the depth of the apparent redox discontinuity in the sediment at high wave stress but not at low wave stress. These results indicate that the effects of biodiversity on some ecosystem functions may be sufficiently strong to generate patterns in ecosystems where other factors are also affecting ecosystem processes, but that the biodiversity-ecosystem function relationship for can be dependent on environmental conditions for specific ecosystem functions.

During the Deepwater Horizon oil well blowout in the Gulf of Mexico, the application of 7 million liters of chemical dispersants aimed to stimulate microbial crude oil degradation by increasing the bioavailability of oil compounds. However, the effects of dispersants on oil biodegradation rates are debated. In laboratory experiments, we simulated environmental conditions comparable to the hydrocarbon-rich, 1,100 m deep plume that formed during the Deepwater Horizon discharge. The presence of dispersant significantly altered the microbial community composition through selection for potential dispersant-degrading Colwellia, which also bloomed in situ in Gulf deep waters during the discharge. In contrast, oil addition to deepwater samples in the absence of dispersant stimulated growth of natural hydrocarbon-degrading Marinobacter. In these deepwater microcosm experiments, dispersants did not enhance heterotrophic microbial activity or hydrocarbon oxidation rates. An experiment with surface seawater from an anthropogenically derived oil slick corroborated the deepwater microcosm results as inhibition of hydrocarbon turnover was observed in the presence of dispersants, suggesting that the microcosm findings are broadly applicable across marine habitats. Extrapolating this comprehensive dataset to real world scenarios questions whether dispersants stimulate microbial oil degradation in deep ocean waters and instead highlights that dispersants can exert a negative effect on microbial hydrocarbon degradation rates.

Graves hyperthyroidism is commonly seen in clinical practice and Takotsubo stress cardiomyopathy is an increasingly recognized cardiac complication of physical or emotional stress. We report the rare case of a patient with Graves hyperthyroidism that was complicated by severe biventricular takotsubo cardiomyopathy, which was demonstrated on heart catheterization. After appropriate pharmacologic treatment of her hyperthyroidism, she had complete resolution of her cardiomyopathy.

Summary The nitrogen (δ15N) and carbon (δ13C) isotope ratios of animal tissues can help identify the composition of diets and open up a myriad of ecological applications. However, consumers do not ingest or assimilate all components of food items, and it is not well understood how sampling different tissues of sources and consumers may affect isotopic values ascribed, and thereby how such variation affects derived ecological measures. Utilizing a simple prey–predator feeding relationship in insects, we examined isotopic differences in soft, exoskeleton and whole tissues using samples with and without lipid extraction. As a derived ecological measure, we calculated trophic discrimination factors, changes in δ15N or δ13C between source and consumer, for the different prey–predator tissue combinations. Lipid extraction did not affect δ15N values, and we found significant tissue differences in δ15N that varied between prey and predator. Lipid extraction enriched δ13C values in most instances, and it was only after extraction of lipids that we observed consistent depletion of δ13C in exoskeleton relative to soft tissues in prey and predator. Isotopic differences between tissue types propagated marked variation in derived ecological parameters. Common sampling practice using whole tissue for prey and predator (whole/whole) resulted in a trophic discrimination factor of 0·48‰ for δ15N, compared with correct factors of 0·97‰ (soft/whole) and 2·18‰ (soft/soft) using prey soft tissue actually ingested by the predator. For δ13C, variation across discrimination factors was less, with whole/whole tissue of −0·14‰, whilst correct factors were −0·55‰ (soft/whole) and −0·04‰ (soft/soft). Our results indicate that tissue selection and preparation are important considerations for isotopic studies using arthropods. Lipid extraction is necessary to derive accurate δ13C values based on proteins, whilst consequences of tissue selection are likely context-dependent: In poorly defined systems where sources are isotopically similar or have larger variance, our results indicate that tissue selection within sources is important to avoid significant error, whether estimating trophic positions or dietary proportions using mixing models. In such cases, we strongly recommend exclusion of source materials not assimilated in consumers.

Increasingly, stable isotope ratios of nitrogen (delta N-15) and carbon (delta C-13) are used to quantify trophic structure, though relatively few studies have tested accuracy of isotopic structural measures. For laboratory-raised and wild-collected plant-invertebrate food chains spanning four trophic levels we estimated nitrogen range (NR) using delta N-15, and carbon range (CR) using delta C-13, which are used to quantify food chain length and breadth of trophic resources respectively. Across a range of known food chain lengths we examined how NR and CR changed within and between food chains. Our isotopic estimates of structure are robust because they were calculated using resampling procedures that propagate variance in sample means through to quantified uncertainty in final estimates. To identify origins of uncertainty in estimates of NR and CR, we additionally examined variation in discrimination (which is change in delta N-15 ordelta C-13 from source to consumer) between trophic levels and among food chains. delta N-15 discrimination showed significant enrichment, while variation in enrichment was species and system specific, ranged broadly (1.4‰ to 3.3‰), and importantly, propagated variation to subsequent estimates of NR. However, NR proved robust to such variation and distinguished food chain length well, though some overlap between longer food chains infers a need for awareness of such limitations. delta C-13 discrimination was inconsistent; generally no change or small significant enrichment was observed. Consequently, estimates of CR changed little with increasing food chain length, showing the potential utility of delta C-13 as a tracer of energy pathways. This study serves as a robust test of isotopic quantification of food chain structure, and given global estimates of aquatic food chains approximate four trophic levels while many food chains include invertebrates, our use of four trophic level plant-invertebrate food chains makes our findings relevant for a majority of ecological systems.