Fungal community composition predicts forest carbon storage at a continental scale.

Forest soils harbor hyper-diverse microbial communities which fundamentally regulate carbon and nutrient cycling across the globe. Directly testing hypotheses on how microbiome diversity is linked to forest carbon storage has been difficult, due to a lack of paired data on microbiome diversity and in situ observations of forest carbon accumulation and storage. Here, we investigated the relationship between soil microbiomes and forest carbon across 238 forest inventory plots spanning 15 European countries. We show that the composition and diversity of fungal, but not bacterial, species is tightly coupled to both forest biotic conditions and a seven-fold variation in tree growth rates and biomass carbon stocks when controlling for the effects of dominant tree type, climate, and other environmental factors. This linkage is particularly strong for symbiotic endophytic and ectomycorrhizal fungi known to directly facilitate tree growth. Since tree growth rates in this system are closely and positively correlated with belowground soil carbon stocks, we conclude that fungal composition is a strong predictor of overall forest carbon storage across the European continent.

Precipitating factors in patients with spontaneous coronary artery dissection: Clinical, laboratoristic and prognostic implications.

BACKGROUND: Spontaneous coronary artery dissection (SCAD) often presents with acute coronary syndrome and underlying pathophysiology involves the interplay between predisposing factors and precipitating stressors, such as emotional and physical triggers. In our study we sought to compare clinical, angiographic and prognostic features in a cohort of patients with SCAD according to the presence and type of precipitating stressors. METHODS: Consecutive patients with angiographic evidence of SCAD were divided into three groups: patients with emotional stressors, patients with physical stressors and those without any stressor. Clinical, laboratoristic and angiographic features were collected for each patient. The incidence of major adverse cardiovascular events, recurrent SCAD and recurrent angina was assessed at follow-up. RESULTS: Among the total population (64 subjects), 41 [64.0%] patients presented with precipitating stressors, including emotional triggers (31 [48.4%] subjects) and physical efforts (10 [15.6%] subjects). As compared with the other groups, patients with emotional triggers were more frequently female (p = 0.009), had a lower prevalence of hypertension (p = 0.039] and dyslipidemia (p = 0.039), were more likely to suffer from chronic stress (p = 0.022) and presented with higher levels of C-reactive protein (p = 0.037) and circulating eosinophils cells (p = 0.012). At a median follow-up of 21 [7; 44] months, patients with emotional stressors experienced higher prevalence of recurrent angina (p = 0.025), as compared to the other groups. CONCLUSIONS: Our study shows that emotional stressors leading to SCAD may identify a SCAD subtype with specific features and a trend towards a worse clinical outcome.

Data from Multiple Portable XRF Units and Their Significance for Ancient Glass Studies.

X-ray fluorescence spectroscopy is a non-destructive technique employed for elemental analysis of a wide range of materials. Its advantages are especially valued in archaeometry, where portable instruments are available. Considering ancient glass, such instruments allow for the detection of some major, minor, and trace elements linked to the deliberate addition of specific components or to impurities in the raw materials of the glass batch. Besides some undoubted advantages, portable XRF (p-XRF) has some limitations that are addressed in this study. The performance assessment of four different p-XRF units and the reconciling of their output were conducted. The results show the limitations in cross-referencing the data obtained from each unit and suggest procedures to overcome the issues. The p-XRF units were tested on the set of Corning reference glasses and on a small set of archaeological glasses with known composition. The compatibility of the output was assessed using multivariate statistical tools. Such a workflow allows us to consider data from multiple sources in the same frame of reference.

Leaf trait plasticity and site-specific environmental variability modulate the severity of visible foliar ozone symptoms in Viburnum lantana.

The assessment of Visible Foliar Symptoms (VFS) is commonly adopted by forest monitoring programs to evaluate ozone impact on vegetation. The occurrence of ozone VFS may differ among individuals of the same species at the same site, and within leaves of the same individual. The aim of this study was to identify site and plant characteristics as well as functional leaf traits associated with the occurrence and severity of VFS in Viburnum lantana (an ozone-sensitive species) and at the scale of an individual site. V. lantana plants growing at one site of the ViburNeT monitoring network (Trentino, North Italy) experiencing high ozone levels were surveyed in relation to 1) sun exposure, 2) shading effect from neighbor vegetation, 3) plant height and 4) presence and severity of VFS. Leaves from three different sections of each plant were subjected to a phenotypic characterization of leaf area, dry weight, specific leaf area (SLA), chlorophyll content (ChlSPAD), percentage of VFS, and adaxial and abaxial trichome density (Tr). We showed that plants at high irradiation levels had significantly lower SLA (p<0.05), higher Tr (p<0.01) and greater ChlSPAD (p<0.01) when compared to shaded and/or west- and north-exposed plants, thus indicating a strong influence of site-specific characteristics on leaf trait plasticity. Similar differences were observed for taller vs. shorter plants and apical vs. basal branches (p<0.05). Ozone-induced VFS at leaf level were associated with lower SLA (p<0.001) and higher Tr in the abaxial leaf surface (p<0.05). Both leaf traits showed significant differences also within the south and east exposed plant category, thus suggesting the increase in leaf thickness and Tr as a potential adaptive strategy under multiple stress conditions. Our results provide evidence of a strong relationship between VFS, leaf traits and site-specific variables, offering new insights for interpreting data on the impact of ozone on vegetation.

Characterization of Castellani nineteenth-century gold jewellery by in situ micro-XRF spectroscopy.

The material characterization of nineteenth-century artifacts is of great interest, due both to the breakthrough technological advances and to the unprecedented spread of forgeries of antiquities which took place in that period. However, this type of artifacts has been largely overlooked in the past. In this paper we present the compositional analysis of gold jewels by the Castellani, one of the most important families of goldsmiths in nineteenth-century Europe. The use of a portable micro-XRF spectrometer, specifically developed for jewellery analysis at the Centro Nacional de Aceleradores (Seville), allowed us to analyse, in a completely non-invasive way, the alloys, joining techniques and surface treatments of the jewels of the Castellani collection at the National Etruscan Museum of Villa Giulia in Rome. The addition to the spectrometer of a second X-rays detector with a zinc filter allowed us to check the possible presence of low amounts of cadmium, a metal added to gold soldering only from the nineteenth century and often used in authenticity studies. Moreover, the relative intensities of the Au X-ray lines were studied in order to check non-invasively the presence of surface enrichments in gold.

Echocardiographically defined haemodynamic categorization predicts prognosis in ambulatory heart failure patients treated with sacubitril/valsartan.

AIM: Echo-derived haemodynamic classification, based on forward-flow and left ventricular (LV) filling pressure (LVFP) correlates, has been proposed to phenotype patients with heart failure and reduced ejection fraction (HFrEF). To assess the prognostic relevance of baseline echocardiographically defined haemodynamic profile in ambulatory HFrEF patients before starting sacubitril/valsartan. METHODS AND RESULTS: In our multicentre, open-label study, HFrEF outpatients were classified into 4 groups according to the combination of forward flow (cardiac index; CI:< or ≥2.0 L/min/m2 ) and early transmitral Doppler velocity/early diastolic annular velocity ratio (E/e': ≥ or <15): Profile-A: normal-flow, normal-pressure; Profile-B: low-flow, normal-pressure; Profile-C: normal-flow, high-pressure; Profile-D: low-flow, high-pressure. Patients were started on sacubitril/valsartan and followed-up for 12.3 months (median). Rates of the composite of death/HF-hospitalization were assessed by multivariable Cox proportional-hazards models. Twelve sites enrolled 727 patients (64 ± 12 year old; LVEF: 29.8 ± 6.2%). Profile-D had more comorbidities and worse renal and LV function. Target dose of sacubitril/valsartan (97/103 mg BID) was more likely reached in Profile-A (34%) than other profiles (B: 32%, C: 24%, D: 28%, P < 0.001). Event-rate (per 100 patients per year) progressively increased from Profile-A to Profile-D (12.0%, 16.4%, 22.9%, and 35.2%, respectively, P < 0.0001). By covariate-adjusted Cox model, profiles with low forward-flow (B and D) remained associated with poor outcome (P < 0.01). Adding this categorization to MAGGIC-score and natriuretic peptides, provided significant continuous net reclassification improvement (0.329; P < 0.001). Intermediate and high-dose sacubitril/valsartan reduced the event's risk independently of haemodynamic profile. CONCLUSIONS: Echocardiographically-derived haemodynamic classification identifies ambulatory HFrEF patients with different risk profiles. In real-world HFrEF outpatients, sacubitril/valsartan is effective in improving outcome across different haemodynamic profiles.

Benefit from sacubitril/valsartan is associated with hemodynamic improvement in heart failure with reduced ejection fraction: An echocardiographic study.

BACKGROUND: Sacubitril/valsartan improves outcome in patients with heart failure (HF) with reduced left ventricular (LV) ejection fraction (EF, HFrEF). However, little is known about possible mechanisms underlying this favourable effect. PURPOSE: To assess changes in echocardiographically-derived hemodynamic profiles induced by sacubitril/valsartan and their impact on outcome. METHODS: In this multicenter, open-label study, 727 HFrEF outpatients underwent comprehensive echocardiography at baseline (before starting sacubitril/valsartan) and after 12 months. Estimated LV filling pressure (E/e') and cardiac index (CI, l/min/m2) were combined to determine 4 hemodynamic profiles: profile-A (normal-flow/normal-pressure); profile-B (low-flow/normal-pressure); profile-C: (normal-flow/high-pressure); profile-D: (low-flow/high-pressure). Changes among categories were recorded, and their associations with rates of the composite of death/HF-hospitalization were assessed by multivariable Cox analysis. RESULTS: At baseline, 29% had profile-A, 15% had profile-B, 32% profile-C, and 24% profile-D. After 12 months, the hemodynamic profile improved in 53% of patients (all profile-A achievers, or profile-D patients achieving either C or B profile), while it remained unchanged in 39% patients and worsened in 9%. Prevalence of improved profile progressively increased with increasing dose of sacubitril/valsartan (P < 0.0001). After the second echocardiography, patients were followed up 12.6 ± 7.6 months: event-rate was lower in patients with improved profile (12.3%, 95%CI: 9.4-16.1) compared to patients in whom hemodynamic profile remained unchanged (29.9%, 24.0-37.3) or worsened (31.2%, 20.7-46.9, P < 0.0001). Improved hemodynamic profile was associated with favourable outcome independent of LVEF and other covariates (HR 0.65, 95%CI: 0.45-0.95, P < 0.05). CONCLUSION: In HFrEF patients, the beneficial prognostic effects of sacubitril/valsartan are associated with improvement in hemodynamic conditions.

HERMES - a GUI-based software tool for pre-processing of X-ray absorption spectroscopy data from laboratory Rowland circle spectrometers.

HERMES, a graphical user interface software tool, is presented, for pre-processing X-ray absorption spectroscopy (XAS) data from laboratory Rowland circle spectrometers, to meet the data handling needs of a growing community of practice. HERMES enables laboratory XAS data to be displayed for quality assessment, merging of data sets, polynomial fitting of smoothly varying data, and correction of data to the true energy scale and for dead-time and leakage effects. The software is written in Java 15 programming language, and runs on major computer operating systems, with graphics implementation using the JFreeChart toolkit. HERMES is freely available and distributed under an open source licence.

Forest tree growth is linked to mycorrhizal fungal composition and function across Europe.

Most trees form symbioses with ectomycorrhizal fungi (EMF) which influence access to growth-limiting soil resources. Mesocosm experiments repeatedly show that EMF species differentially affect plant development, yet whether these effects ripple up to influence the growth of entire forests remains unknown. Here we tested the effects of EMF composition and functional genes relative to variation in well-known drivers of tree growth by combining paired molecular EMF surveys with high-resolution forest inventory data across 15 European countries. We show that EMF composition was linked to a three-fold difference in tree growth rate even when controlling for the primary abiotic drivers of tree growth. Fast tree growth was associated with EMF communities harboring high inorganic but low organic nitrogen acquisition gene proportions and EMF which form contact versus medium-distance fringe exploration types. These findings suggest that EMF composition is a strong bio-indicator of underlying drivers of tree growth and/or that variation of forest EMF communities causes differences in tree growth. While it may be too early to assign causality or directionality, our study is one of the first to link fine-scale variation within a key component of the forest microbiome to ecosystem functioning at a continental scale.

Climatic and stand drivers of forest resistance to recent bark beetle disturbance in European coniferous forests.

Bark beetle infestation is a major driver of tree mortality that may be critical for forest persistence under climate change and the forecasted increase of extreme heat and drought episodes. Under this context, the environmental position of host tree populations within the species' climatic niche (central vs. marginal populations) is expected to be a determinant in the dynamics of insect-host systems. Here, we analyzed the recent patterns of bark beetle disturbance and forest resistance across European coniferous forests during the 2010-2018 period. We obtained bark beetle attack and tree mortality data from successive continental-scale forest condition surveys on 130 plots including five host trees and five bark beetle species, and characterized the climatic niche of each species. Then, we analyzed the overall forest resistance and species-specific responses, in terms of bark beetle attack and induced tree mortality, in relation to the distance to the niche optimum of both host tree and beetle species, previous drought events, and plot characteristics. Regional patterns of recent disturbance revealed that forests in central, north, and east of Europe could be at risk under the attack of multivoltine bark beetle species. We found that overall forest resistance to beetle attack was determined by several driving factors, which varied among species responses. Particularly, the environmental position of the affected forest within the host and beetle species' climatic niche and plot characteristics mediated the influence of drought on the resistance to beetle attack. In turn, forest resistance to induced tree mortality was determined exclusively by the maximum intensity and duration of drought events. Our findings highlight the importance of disturbance interactions and suggest that the joint influence of drought events and bark beetle disturbance will threaten the persistence of European coniferous forests, even in those tree populations close to their species' climatic optimum.

The FutureS of healthcare.

This editorial for the special issue of FutureS is not intended to provide a comprehensive, analytical overview of the future of health care; rather, it collects the perspectives on which scholars have focused most. There is a danger that what we report will quickly become obsolete for numerous reasons; think of the speed of current technological progress or the fact that the Covid-19 pandemic could further stress health care systems around the world. However, we would like to outline some of the current topics explored in the literature and focus on the scenarios envisioned by practitioners. We write this piece being interested in the innovative impulses of all the actors belonging to the "renewed" health care ecosystem, aware of the fact that there are significant differences between the countries of the North and South of the world and, consequently, between their health care systems. What we can say with certainty is that the healthcare and life sciences are the protagonists of an unparalleled revolution. The aging population and changing needs, the increasingly common occurrence of chronic disorders, and digitization are some of the challenges facing the sector. The technological change of the fourth industrial revolution is disruptive and changes the logic of the market, not only that of healthcare but also that of adjacent markets. Because of the intensity with which insiders have to face these new trends, the topic has been the focus of interest of scholars and practitioners in recent years. The big players in consulting, as well as the scholars, have deepened the issues of healthcare of the future, focusing on what will be the major challenges in 10 years and imagining potential scenarios that will reconfigure the way health care is delivered and used. In the next 10 years, there will be profound demographic changes and the healthcare system will necessarily have to reconfigure the supply of the necessary services and the methods of delivery (KPMG, 2018). Due to the aging of the population, there has already been a dramatic increase in chronic and degenerative diseases requiring complex treatment in recent years. In addition, the Covid-19 pandemic that has been sweeping the world since 2019 has strained global health systems, revealed already existing weaknesses, even in the most advanced countries, and is representing an important moment of reflection for all policymakers. The whole world is questioning what will need to be done to foster greater effectiveness of national systems as well as better capacity to cope with shocks of such magnitude. In this document we explore what practitioners and scholars consider the main future challenges and the major changes that need to be made in the healthcare sector in order to embrace a new paradigm of care, based on the centrality of the patient, on prevention and not on cure, on technologies at the side of humans.

Assessing the response of forest productivity to climate extremes in Switzerland using model-data fusion.

The response of forest productivity to climate extremes strongly depends on ambient environmental and site conditions. To better understand these relationships at a regional scale, we used nearly 800 observation years from 271 permanent long-term forest monitoring plots across Switzerland, obtained between 1980 and 2017. We assimilated these data into the 3-PG forest ecosystem model using Bayesian inference, reducing the bias of model predictions from 14% to 5% for forest stem carbon stocks and from 45% to 9% for stem carbon stock changes. We then estimated the productivity of forests dominated by Picea abies and Fagus sylvatica for the period of 1960-2018, and tested for productivity shifts in response to climate along elevational gradient and in extreme years. Simulated net primary productivity (NPP) decreased with elevation (2.86 ± 0.006 Mg C ha-1  year-1  km-1 for P. abies and 0.93 ± 0.010 Mg C ha-1  year-1  km-1 for F. sylvatica). During warm-dry extremes, simulated NPP for both species increased at higher and decreased at lower elevations, with reductions in NPP of more than 25% for up to 21% of the potential species distribution range in Switzerland. Reduced plant water availability had a stronger effect on NPP than temperature during warm-dry extremes. Importantly, cold-dry extremes had negative impacts on regional forest NPP comparable to warm-dry extremes. Overall, our calibrated model suggests that the response of forest productivity to climate extremes is more complex than simple shift toward higher elevation. Such robust estimates of NPP are key for increasing our understanding of forests ecosystems carbon dynamics under climate extremes.

Pervasive decreases in living vegetation carbon turnover time across forest climate zones.

Forests play a major role in the global carbon cycle. Previous studies on the capacity of forests to sequester atmospheric CO2 have mostly focused on carbon uptake, but the roles of carbon turnover time and its spatiotemporal changes remain poorly understood. Here, we used long-term inventory data (1955 to 2018) from 695 mature forest plots to quantify temporal trends in living vegetation carbon turnover time across tropical, temperate, and cold climate zones, and compared plot data to 8 Earth system models (ESMs). Long-term plots consistently showed decreases in living vegetation carbon turnover time, likely driven by increased tree mortality across all major climate zones. Changes in living vegetation carbon turnover time were negatively correlated with CO2 enrichment in both forest plot data and ESM simulations. However, plot-based correlations between living vegetation carbon turnover time and climate drivers such as precipitation and temperature diverged from those of ESM simulations. Our analyses suggest that forest carbon sinks are likely to be constrained by a decrease in living vegetation carbon turnover time, and accurate projections of forest carbon sink dynamics will require an improved representation of tree mortality processes and their sensitivity to climate in ESMs.

The future of quantum biology.

Biological systems are dynamical, constantly exchanging energy and matter with the environment in order to maintain the non-equilibrium state synonymous with living. Developments in observational techniques have allowed us to study biological dynamics on increasingly small scales. Such studies have revealed evidence of quantum mechanical effects, which cannot be accounted for by classical physics, in a range of biological processes. Quantum biology is the study of such processes, and here we provide an outline of the current state of the field, as well as insights into future directions.

Scarce evidence of ozone effect on recent health and productivity of alpine forests-a case study in Trentino, N. Italy.

We investigated the significance of tropospheric ozone as a factor explaining recent tree health (in terms of defoliation) and productivity (in terms of basal area increment, BAI) in 15 ICP Forests level I and one level II plots in alpine forests in Trentino (N. Italy). Mean daily ozone summer concentrations varied between 30 and 72 parts per billion (ppb) leading to large exceedance of concentration-based critical levels set to protect forest trees. Phytoxic ozone dose (POD0) estimated at the level II plot over the period 1996-2009 was 31-61 mmol m-2 projected leaf area (PLA). The role of ozone was investigated taking into account other site and environmental factors. Simple linear regression, multiple linear regression (MLR, to study mean periodical defoliation and mean periodical BAI), and linear mixed models (LMM, to study annual defoliation data) were used. Our findings suggest that-regardless of the metric adopted-tropospheric ozone is not a significant factor in explaining recent status and trends of defoliation and BAI in the alpine region examined. Both defoliation and BAI are in turn driven by biotic/abiotic damage, nutritional status, DBH (assumed as a proxy for age), and site characteristics. These results contrast with available ozone-growth dose response relationships (DRRs) and other observational studies. This may be due to a variety of concurrent reasons: (i) DRRs developed for individual saplings under controlled condition are not necessarily valid for population of mature trees into real forest ecosystems; (ii) some observational studies may have suffered from biased design; and (iii) since alpine forests have been exposed to high ozone levels (and other oxidative stress) over decades, possible acclimation mechanisms cannot be excluded.

In search for evidence: combining ad hoc survey, monitoring, and modeling to estimate the potential and actual impact of ground level ozone on forests in Trentino (Northern Italy).

A 5-year project was carried out over the period 2007-2011 to estimate the potential and actual ozone effect on forests in Trentino, Northern Italy (6207 km2) (Ozone EFFORT). The objective was to provide explicit answers to three main questions: (i) is there a potential risk placed by ozone to vegetation? (ii) are there specific ozone symptoms on vegetation, and are they related to ozone levels? (iii) are there ozone-related effects on forest health and growth? Different methods and techniques were adopted as follows: monitoring ozone levels, ad hoc field survey for symptoms on vegetation and chlorophyll-related measurements, modeling to upscale ozone measurements, ozone flux estimation, statistical analysis, and modeling to detect whether a significant effect attributable to ozone exists. Ozone effects were assessed on an ad hoc-introduced bioindicator, on spontaneous woody species, and on forest trees. As for question (i), the different ozone-risk critical levels for both exposure and stomatal flux were largely exceeded in Trentino, evidencing a potentially critical situation for vegetation. As for question (ii), specific ozone foliar symptoms related to ozone exposure levels were observed on the introduced supersensitive Nicotiana tabacum L. cv Bel-W3 and on the spontaneous, ozone-sensitive Viburnum lantana L., but not on other 33 species surveyed in the field studies. Regarding question (iii), statistical analyses on forest health (in terms of defoliation) and growth (in terms of basal area increment) measured at 15 forest monitoring plots and tree rings (at one site) revealed no significant relationship with ozone exposure and flux. Instead, a set of factors related to biotic and abiotic causes, foliar nutrients, age, and site were identified as the main drivers of forest health and growth. In conclusion, while ozone levels and fluxes in the investigated region were much higher than current critical levels, evidence of impact on vegetation-and on forest trees in particular-was limited.

Evidence for coherent mixing of excited and charge-transfer states in the major plant light-harvesting antenna, LHCII.

LHCII, the major light harvesting antenna from plants, plays a dual role in photosynthesis. In low light it is a light-harvester, while in high light it is a quencher that protects the organism from photodamage. The switching mechanism between these two orthogonal conditions is mediated by protein dynamic disorder and photoprotective energy dissipation. The latter in particular is thought to occur in part via spectroscopically 'dark' states. We searched for such states in LHCII trimers from spinach, at both room temperature and at 77 K. Using 2D electronic spectroscopy, we explored coherent interactions between chlorophylls absorbing on the low-energy side of LHCII, which is the region that is responsible for both light-harvesting and photoprotection. 2D beating frequency maps allow us to identify four frequencies with strong excitonic character. In particular, our results show the presence of a low-lying state that is coupled to a low-energy excitonic state. We assign this to a mixed excitonic-charge transfer state involving the state with charge separation within the Chl a603-b609 heterodimer, borrowing some dipole strength from the Chl a602-a603 excited states. Such a state may play a role in photoprotection, in conjunction with specific and environmentally controlled realizations of protein dynamic disorder. Our identification and assignment of the coherences observed in the 2D frequency maps suggests that the structure of exciton states as well as a mixing of the excited and charge-transfer states is affected by coupling of these states to resonant vibrations in LHCII.

The impact of regional policies on emergency department management and performance: the case of the regional government of Sicily.

BACKGROUND: Improvement in healthcare, seeking the correct balance between quality and costs, is an ongoing concern in many countries. Many countries have developed and implemented improvement programmes in health care, particularly in emergency departments (ED), which play a key role in terms of hospital resources and planning. The regional government of Sicily implemented a project 2010-2012 to improve ED care quality and patient safety. PURPOSE: This paper aims to evaluate improvements implemented by the Regional Health Authority of Sicily in the 20 main EDs. METHOD: Performance analysis of EDs was conducted on three levels: care quality (standard Joint Commission International evaluation), efficiency in terms of resources and output (by way of interviews and document analysis) and the role of management in efficiently promoting change (presence of a performance monitoring system). FINDINGS: The results show improvements in all areas and improved performance in all EDs. There is, however, room for improvement in certain areas, and improvement was not uniformly distributed. PRACTICAL IMPLICATIONS: The quality of local policy and management are key aspects of efficient promotion of performance improvement. Copyright © 2015 John Wiley & Sons, Ltd.

Dark States in the Light-Harvesting complex 2 Revealed by Two-dimensional Electronic Spectroscopy.

Energy transfer and trapping in the light harvesting antennae of purple photosynthetic bacteria is an ultrafast process, which occurs with a quantum efficiency close to unity. However the mechanisms behind this process have not yet been fully understood. Recently it was proposed that low-lying energy dark states, such as charge transfer states and polaron pairs, play an important role in the dynamics and directionality of energy transfer. However, it is difficult to directly detect those states because of their small transition dipole moment and overlap with the B850/B870 exciton bands. Here we present a new experimental approach, which combines the selectivity of two-dimensional electronic spectroscopy with the availability of genetically modified light harvesting complexes, to reveal the presence of those dark states in both the genetically modified and the wild-type light harvesting 2 complexes of Rhodopseudomonas palustris. We suggest that Nature has used the unavoidable charge transfer processes that occur when LH pigments are concentrated to enhance and direct the flow of energy.