•Overview of methods to quantify recharge in ephemeral and intermittent streams.•Provides temporal and spatial scales of recharge measured using each method.•Identifies gaps in the literature and ...suggests future directions.
Aquifer recharge through ephemeral streambeds is believed to be a major source of groundwater recharge in arid areas; however, comparatively few studies quantify this streamflow recharge. This review synthesizes the available field-based aquifer recharge literature from arid regions around the world. Seven methods for quantifying ephemeral and intermittent stream infiltration and aquifer recharge are reviewed; controlled infiltration experiments, monitoring changes in water content, heat as a tracer of infiltration, reach length water balances, floodwave front tracking, groundwater mounding, and groundwater dating. The pertinent temporal and spatial scales, as well as the advantages and limitations of each method are illustrated with examples from the literature. Comparisons between the methods are used to highlight appropriate uses of each field method, with emphasis on the advantages of using multiple methods within a study in order to avoid the potential drawbacks inherent in any single method. Research needs are identified, including: quantitative uncertainty analysis, long-term data collection and analysis, understanding of the role of riparian vegetation, and reconciliation of transmission losses and infiltration estimates with actual aquifer recharge.
Despite enormous advances, management of multiple myeloma (MM) remains challenging. Multiple factors impact the decision to treat or which regimen to use at MM relapse/progression. Recent major ...randomized controlled trials (RCTs) showed widely varying progression-free survivals (PFS), ranging from a median of 4 months (MM-003) to 23.6 months (ASPIRE). Based on these RCTs, next-generation proteasome inhibitors (carfilzomib and ixazomib), next-generation immunomodulatory agent (pomalidomide), and monoclonal antibodies (elotuzumab and daratumumab) were approved for relapsed and refractory MM. Daratumumab, targeting CD38, has multiple mechanisms of action including modulation of the immunosuppressive bone marrow micro-environment. In addition to the remarkable single agent activity in refractory MM, daratumumab produced deep responses and superior PFS in MM when combined with lenalidomide/dexamethasone, or bortezomib/dexamethasone. Other anti-CD38 antibodies, such as isatuximab and MOR202, are undergoing assessment. Elotuzumab, targeting SLAMF7, yielded superior response rates and PFS when combined with lenalidomide/dexamethasone. New combinations of these next generation novel agents and/or antibodies are undergoing clinical trials. Venetoclax, an oral BH3 mimetic inhibiting BCL2, showed single agent activity in MM with t(11;14), and is being studied in combination with bortezomib/dexamethasone. Selinexor, an Exportin-1 inhibitor, yielded promising results in quad- or penta-refractory MM including patients resistant to daratumumab. Pembrolizumab, an anti-PD1 check-point inhibitor, is being tested in combination with lenalidomide/dexamethasone or pomalidomide/dexamethasone. Chimeric antigen receptor-T cells targeting B-cell maturation antigen have yielded deep responses in RRMM. Finally, salvage autologous stem cell transplantation (ASCT) remains an important treatment in MM relapsing/progressing after a first ASCT. Herein, the clinical trial data of these agents are summarized, cautious interpretation of RCTs highlighted, and algorithm for salvage treatment of relapse/refractory MM proposed.
Phylogenetic niche conservatism (PNC) is the tendency of lineages to retain their niche-related traits through speciation events. A recent surge in the availability of well-sampled molecular ...phylogenies has stimulated phylogenetic approaches to understanding ecological processes at large geographical scales and through macroevolutionary time. We stress that PNC is a pattern, not a process, and is found only in some traits and some lineages. At the simplest level, a pattern of PNC is an inevitable consequence of evolution – descent with modification and divergence of lineages – but several intrinsic causes, including physicochemical, developmental and genetic constraints, can lead directly to a marked pattern of PNC. A pattern of PNC can also be caused indirectly, as a by-product of other causes, such as extinction, dispersal limitation, competition and predation. Recognition of patterns of PNC can contribute to understanding macroevolutionary processes: for example, release from constraint in traits has been hypothesized to trigger adaptive radiations such as that of the angiosperms. Given the multiple causes of patterns of PNC, tests should address explicit questions about hypothesized processes. We conclude that PNC is a scientifically useful concept with applications to the practice of ecological research.
To obtain prevalence estimates of age-related macular degeneration (AMD; late, geographic atrophy, neovascular) by age and gender amongst populations of European ancestry taking into account study ...design and time trends.
Systematic review of population-based studies published by September 2010 with quantitative estimates of geographic atrophy (GA), neovascular (NV), and late AMD prevalence. Studies were identified by a literature search of MEDLINE (from 1950), EMBASE (from 1980), and Web of Science (from 1980) databases.
Data from 25 published studies (57 173 subjects: 455 with GA, 464 with NVAMD, and 1571 with late AMD).
Bayesian meta-regression of the log odds of AMD with age, gender, and year of study allowing for differences in study design characteristics, to estimate prevalences of AMD (late, GA, NVAMD) along with 95% credible intervals (CrI).
Log odds and prevalence of AMD.
There was considerable heterogeneity in prevalence rates between studies; for late AMD, 20% of the variability in prevalence rates was explained by differences in age and 50% by study characteristics. The prevalence of AMD increased exponentially with age (odds ratio OR, 4.2 per decade; 95% CrI, 3.8-4.6), which did not differ by gender. There was some evidence to suggest higher risk of NVAMD in women compared with men (OR, 1.2; 95% CrI, 1.0-1.5). Compared with studies using fundus imaging and international classification systems, studies using fundus imaging with alternative classifications were more likely (OR, 2.7; 95% CrI, 1.1-2.8), and studies using alternative classifications without fundus imaging most likely to diagnose late AMD (OR, 2.9; 95% CrI, 1.3-7.8). There was no good evidence of trends in AMD prevalence over time. Estimated prevalence of late AMD is 1.4% (95% CrI, 1.0%-2.0%) at 70 years of age, rising to 5.6% (95% CrI, 3.9%-7.7%) at age 80 and 20% (95% CrI, 14%-27%) at age 90.
Studies using recognized classifications systems with fundus photography reported the lowest prevalences of AMD taking account of age and gender, and were stable over time, with a potentially higher risk of NVAMD for women. These prevalence estimates can be used to guide health service provision in populations of European ancestry.
Migration is a striking behavioral strategy by which many animals enhance resource acquisition while reducing predation risk. Historically, the demographic benefits of such movements made migration ...common, but in many taxa the phenomenon is considered globally threatened. Here we describe a long-term decline in the productivity of elk (
Cervus elaphus
) that migrate through intact wilderness areas to protected summer ranges inside Yellowstone National Park, USA. We attribute this decline to a long-term reduction in the demographic benefits that ungulates typically gain from migration. Among migratory elk, we observed a 21-year, 70% reduction in recruitment and a 4-year, 19% depression in their pregnancy rate largely caused by infrequent reproduction of females that were young or lactating. In contrast, among resident elk, we have recently observed increasing recruitment and a high rate of pregnancy. Landscape-level changes in habitat quality and predation appear to be responsible for the declining productivity of Yellowstone migrants. From 1989 to 2009, migratory elk experienced an increasing rate and shorter duration of green-up coincident with warmer spring-summer temperatures and reduced spring precipitation, also consistent with observations of an unusually severe drought in the region. Migrants are also now exposed to four times as many grizzly bears (
Ursus arctos
) and wolves (
Canis lupus
) as resident elk. Both of these restored predators consume migratory elk calves at high rates in the Yellowstone wilderness but are maintained at low densities via lethal management and human disturbance in the year-round habitats of resident elk. Our findings suggest that large-carnivore recovery and drought, operating simultaneously along an elevation gradient, have disproportionately influenced the demography of migratory elk. Many migratory animals travel large geographic distances between their seasonal ranges. Changes in land use and climate that disparately influence such seasonal ranges may alter the ecological basis of migratory behavior, representing an important challenge for, and a powerful lens into, the ecology and conservation of migratory taxa.
Systematic review of published population based surveys to examine the relationship between primary open angle glaucoma (POAG) prevalence and demographic factors. A literature search identified ...population-based studies with quantitative estimates of POAG prevalence (to October 2014). Multilevel binomial logistic regression of log-odds of POAG was used to examine the effect of age and gender among populations of different geographical and ethnic origins, adjusting for study design factors. Eighty-one studies were included (37 countries, 216 214 participants, 5266 POAG cases). Black populations showed highest POAG prevalence, with 5.2% (95% credible interval (CrI) 3.7%, 7.2%) at 60 years, rising to 12.2% (95% CrI 8.9% to 16.6%) at 80 years. Increase in POAG prevalence per decade of age was greatest among Hispanics (2.31, 95% CrI 2.12, 2.52) and White populations (1.99, 95% CrI 1.86, 2.12), and lowest in East and South Asians (1.48, 95% CrI 1.39, 1.57; 1.56, 95% CrI 1.31, 1.88, respectively). Men were more likely to have POAG than women (1.30, 95% CrI 1.22, 1.41). Older studies had lower POAG prevalence, which was related to the inclusion of intraocular pressure in the glaucoma definition. Studies with visual field data on all participants had a higher POAG prevalence than those with visual field data on a subset. Globally 57.5 million people (95% CI 46.4 to 73.1 million) were affected by POAG in 2015, rising to 65.5 million (95% CrI 52.8, 83.2 million) by 2020. This systematic review provides the most precise estimates of POAG prevalence and shows omitting routine visual field assessment in population surveys may have affected case ascertainment. Our findings will be useful to future studies and healthcare planning.
Robust establishment of survival in multiple myeloma (MM) and its relationship to recurrent genetic aberrations is required as outcomes are variable despite apparent similar staging. We assayed copy ...number alterations (CNA) and translocations in 1036 patients from the NCRI Myeloma XI trial and linked these to overall survival (OS) and progression-free survival. Through a meta-anlysis of these data with data from MRC Myeloma IX trial, totalling 1905 newly diagnosed MM patients (NDMM), we confirm the association of t(4;14), t(14;16), t(14;20), del(17p) and gain(1q21) with poor prognosis with hazard ratios (HRs) for OS of 1.60 (P=4.77 × 10
), 1.74 (P=0.0005), 1.90 (P=0.0089), 2.10 (P=8.86 × 10
) and 1.68 (P=2.18 × 10
), respectively. Patients with 'double-hit' defined by co-occurrence of at least two adverse lesions have an especially poor prognosis with HRs for OS of 2.67 (P=8.13 × 10
) for all patients and 3.19 (P=1.23 × 10
) for intensively treated patients. Using comprehensive CNA and translocation profiling in Myeloma XI we also demonstrate a strong association between t(4;14) and BIRC2/BIRC3 deletion (P=8.7 × 10
), including homozygous deletion. Finally, we define distinct sub-groups of hyperdiploid MM, with either gain(1q21) and CCND2 overexpression (P<0.0001) or gain(11q25) and CCND1 overexpression (P<0.0001). Profiling multiple genetic lesions can identify MM patients likely to relapse early allowing stratification of treatment.
Traditionally, groundwater and surface water flow models have been calibrated against two observation types: hydraulic heads and surface water discharge. It has repeatedly been demonstrated, however, ...that these classical observations do not contain sufficient information to calibrate flow models. To reduce the predictive uncertainty of flow models, the consideration of other observation types constitutes a promising way forward. Despite the ever‐increasing availability of other observation types, however, they are still unconventional when it comes to flow model calibration. By reviewing studies that included nonclassical observations in flow model calibration, benefits and challenges associated with their integration in flow model calibration were identified, and their information content was analyzed. While explicit simulation of mass transport processes in flow models poses challenges, even simplified approaches to integrate tracer concentrations yield significantly better calibration results than using only classical observations. For a majority of calibrated flow models, observations of tracer concentrations and of exchange fluxes were beneficial. Temperature observations improved the simulation of heat transport but often worsened all other model outcomes. Only when temperature observations were made within 2 m of the surface water‐groundwater interface did they have the potential to also improve flow and mass transport simulations. Surprisingly, many models were calibrated manually rather than with the widely available, mathematically robust and automated tools. There is a clear need for more systematic implementation of unconventional observations and automated flow model calibration as well as for more systematic quantification of the information content of unconventional observations.
Plain Language Summary
Traditionally, groundwater and surface water flow models, which are critical for water resources assessment, have been calibrated against only two classical observation types: groundwater levels and surface water discharge. In the past, it has repeatedly been demonstrated that these classical observations do not contain sufficient information to calibrate the parameters required for the simulation of groundwater and surface water flow systems. Owing to the rapid development of measurement techniques throughout the last three decades, however, many other observations of hydrological systems have become widely available. Despite this, observation types other than the classical ones are still unconventional when it comes to flow model calibration. The overall goal of this review is to identify optimal observation types and procedures for flow model calibration and hydrological predictions. We found that observations of tracer concentrations and exchange fluxes are beneficial for most flow models. Temperatures improve the simulation of heat transport but often worsen other flow model outcomes, unless temperatures are measured within 2 m of the surface water‐groundwater interface. We identified a need for more systematic implementation of unconventional observations in flow model calibration and for more systematic quantification of the information content of unconventional observations.
Key Points
The use and information content of diverse observations for groundwater model calibration are assessed
Most unconventional observations strongly improve the calibration of integrated groundwater flow models
Fluxes and tracer concentrations are of larger benefit for groundwater model calibration than temperature observations
Each spring, migratory herbivores around the world track or ‘surf’ green waves of newly emergent vegetation to distant summer or wet‐season ranges. This foraging tactic may help explain the great ...abundance of migratory herbivores on many seasonal landscapes. However, the underlying fitness benefits of this life‐history strategy remain poorly understood. A fundamental prediction of the green‐wave hypothesis is that migratory herbivores obtain fitness benefits from surfing waves of newly emergent vegetation more closely than their resident counterparts. Here we evaluate whether this behavior increases body‐fat levels – a critically important correlate of reproduction and survival for most ungulates – in elk Cervus elaphus of the Greater Yellowstone Ecosystem. Using satellite imagery and GPS tracking data, we found evidence that migrants (n = 23) indeed surfed the green wave, occupying sites 12.7 days closer to peak green‐up than residents (n = 16). Importantly, individual variation in surfing may help account for up to 6 kg of variation in autumn body‐fat levels. Our findings point to a pathway for anthropogenic changes to the green wave (e.g. climate change) or migrants’ ability to surf it (e.g. development) to impact migratory populations. To explore this possibility, we evaluated potential population‐level consequences of constrained surfing with a heuristic model. If green‐wave surfing deteriorates by 5–15 days from observed, our model predicts up to a 20% decrease in pregnancy rates, a 2.5% decrease in population growth, and a 30% decrease in abundance over 50 years. By linking green‐wave surfing to fitness and illustrating potential effects on population growth, our study provides new insights into the evolution of migratory behavior and the prospects for the persistence of migratory ungulate populations in a changing world.
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