Spatial patterns of agricultural expansion determine impacts on biodiversity and carbon storage

The agricultural expansion and intensification required to meet growing food and agri-based product demand present important challenges to future levels and management of biodiversity and ecosystem services. Influential actors such as corporations, governments, and multilateral organizations have made commitments to meeting future agricultural demand sustainably and preserving critical ecosystems. Current approaches to predicting the impacts of agricultural expansion involve calculation of total land conversion and assessment of the impacts on biodiversity or ecosystem services on a per-area basis, generally assuming a linear relationship between impact and land area. However, the impacts of continuing land development are often not linear and can vary considerably with spatial configuration. We demonstrate what could be gained by spatially explicit analysis of agricultural expansion at a large scale compared with the simple measure of total area converted, with a focus on the impacts on biodiversity and carbon storage. Using simple modeling approaches for two regions of Brazil, we find that for the same amount of land conversion, the declines in biodiversity and carbon storage can vary two- to fourfold depending on the spatial pattern of conversion. Impacts increase most rapidly in the earliest stages of agricultural expansion and are more pronounced in scenarios where conversion occurs in forest interiors compared with expansion into forests from their edges. This study reveals the importance of spatially explicit information in the assessment of land-use change impacts and for future land management and conservation.Agriculture is a major contributor to land transformation and hence a threat to the levels of biodiversity and ecosystem services (ES) vital to human endeavors and from which agriculture itself benefits. Growth in agriculture continues to accelerate, and it is estimated that agricultural lands could occupy an additional 200–300 million ha globally (mostly in Latin America and sub-Saharan Africa) in the next 40 y (1). With such mounting pressure and so much at stake, it is essential to find ways to meet agricultural demand while conserving critical ecosystems and minimizing overall impacts. In response, influential actors such as corporations and governments are creating policies, initiatives, agreements and the like that determine how and where agricultural development occurs. Typically, the objectives of these activities are based on reducing the relative and/or total impact of agriculture through avoidance of areas of High Conservation Value (2, 3) or High Carbon Stock (4).Managing the demand for new agricultural land is undeniably important, and predictive modeling approaches for land development and management are urgently needed to better inform decision-making. Representation of the future for agriculture as a polarized choice between intensification and agricultural expansion is overly simplistic and unrealistic, especially given recent reports that yields of key commodities are saturating at levels far below that needed to meet increased demand (5). Future land development and management strategies will need to consider “land-sparing” approaches that consolidate and maximally intensify agriculture (6, 7) and “land-sharing” approaches that integrate natural and agricultural land into a more continuous mosaic (8, 9). It is likely that different strategies will work better in different places and at different scales, but questions about the optimal configuration and integration of agricultural and natural landscapes remain. To assess the impacts of future agricultural expansion at a landscape level, it is important to consider how and where such expansion may occur to understand resulting impacts on biodiversity and ES. Ecological theory suggests that the marginal value of the benefit provided by each unit of habitat conserved changes with the amount of total habitat area (10), and depending on the service, marginal values for the same type of habitat can vary widely based on its location relative to other habitat (11). Techniques for landscape optimization demonstrate the importance of where different land uses occur in determining the aggregate level of biodiversity or ES produced by a landscape (12).Recent advances in scientific understanding and data availability have improved our ability to predict the impacts of land-use change on the levels of biodiversity and ES at the landscape level and have enabled the development of spatially explicit models of these ecosystem processes under different landscape configurations (13, 14). Tools to model the spatial variation in land-use change impacts on biodiversity and ES, including InVEST (Integrated Valuation of Ecosystem Services and Trade-Offs) (15), GLOBIO (16), ARIES (17), and others, are now being used to help inform a wide range of decisions related to land-use planning, infrastructure investment, urban water supplies, and disaster risk reduction (18–21). In contrast to much of this site-based work often occurring in governmental decision contexts, considerations of biodiversity and ES by corporations and multilateral organizations typically rely on approaches that assign an amount of benefit or impact on a per-area basis, without representation of spatial variability (22). Global actors that indirectly or directly affect land use through sourcing decisions for commodity supply chains or investment decisions setting incentives for development would be better informed by approaches that could illustrate how their decisions play out across space.In this paper we examine the impact of different spatial patterns of agricultural expansion on biodiversity (a metric of the average species response, mean species abundance) (Methods) and carbon storage (above-ground and below-ground biomass) to determine the degree to which the impacts of agricultural expansion can be reduced simply by influencing the pattern of land conversion. Many other ES, notably the provision of water, but also pollination and pest control, are vitally important to the continued productivity of agriculture. All of these services, as well as agricultural productivity itself, are variable in their production over space and their response to land-use change and are therefore important to consider in this way as well. We focus on carbon and biodiversity here as a first step because they feature prominently in existing sustainability assessments and are often considered solely on a per-area basis. Our goal is to highlight the importance of considering not only the total area of agricultural expansion, but also where the expansion occurs, differentiating between agricultural decisions that spread a small amount of impact over many places and those that consolidate a larger impact in fewer places. Field evidence shows lower biodiversity in small patches of forest and lower carbon stored in forest edges (see Methods for more detail). Translating such site-based information to broader assessment approaches is necessary to understand the potential importance of spatial configuration to land-use change impacts.     

In vivo assessment of caries excavation with a fluorescence camera compared to direct bacteriological sampling and quantitative analysis using flow cytometry

Lasers in Medical Science - The aim of this study was to assess the performance of the fluorescence camera device VistaCam iX (VC) for the control of caries excavation compared to visual assessment...     

Negative stress echocardiographic study predicts excellent long-term prognosis in patients with erectile dysfunction

Background: Subjects with erectile dysfunction share common risk factors as those for coronary artery disease. However, there are no data on the role of stress echocardiography in assessing the prognosis of patients with erectile dysfunction. Hypothesis: We sought to determine the prognostic utility of negative stress echocardiography study in subjects with erectile dysfunction and compare it to similar subjects without erectile dysfunction. Methods: Between October 1996 and December 1997, 236 patients had negative stress echocardiograms. There were 28 patients with erectile dysfunction. There was a higher prevalence of diabetes in the erectile dysfunction group (64% vs. 35%, P=0.005). The prevalence of other risk factors was similar in the two groups. Follow-up was obtained for 233 patients for a mean duration of 25 months. Results: At the end of follow-up, there was no significant difference in the annualized occurrence of cardiac events between the two groups (4.6% vs. 4.3%, P=NS). Of note, none of the patients were prescribed sildenafil and none of the cardiac events were related to sexual activity. Conclusions: Our study shows that subjects with erectile dysfunction who have a negative stress echocardiographic study have a comparable event rate to similar subjects at high risk for cardiac events on long-term follow-up.     

Neural auditory contrast enhancement in humans

The perception of sensory events can be enhanced or suppressed by the surrounding spatial and temporal context in ways that facilitate the detection of novel objects and contribute to the perceptual constancy of those objects under variable conditions. In the auditory system, the phenomenon known as auditory enhancement reflects a general principle of contrast enhancement, in which a target sound embedded within a background sound becomes perceptually more salient if the background is presented first by itself. This effect is highly robust, producing an effective enhancement of the target of up to 25 dB (more than two orders of magnitude in intensity), depending on the task. Despite the importance of the effect, neural correlates of auditory contrast enhancement have yet to be identified in humans. Here, we used the auditory steady-state response to probe the neural representation of a target sound under conditions of enhancement. The probe was simultaneously modulated in amplitude with two modulation frequencies to distinguish cortical from subcortical responses. We found robust correlates for neural enhancement in the auditory cortical, but not subcortical, responses. Our findings provide empirical support for a previously unverified theory of auditory enhancement based on neural adaptation of inhibition and point to approaches for improving sensory prostheses for hearing loss, such as hearing aids and cochlear implants.

Across sensory domains, perception and its underlying neural substrates are highly dependent on context (1). Such context dependence improves neural coding efficiency (2, 3) and plays a key role in adapting sensory systems to the long-term properties of the environment, thereby enhancing sensitivity to novel events (4) and helping to establish perceptual constancy under a wide range of backgrounds and environments (5). The influence of context in hearing can be illustrated with an effect known as auditory enhancement (6, 7). In this paradigm, a target embedded within a background sound can “pop out” perceptually if the background sound is presented by itself first (Fig. 1A). This effect is highly robust, with the enhancement of the target corresponding to an intensity increase of between 5 and 25 dB (i.e., more than two orders of magnitude), depending on the task (8, 9). It is also ecologically relevant, as it reflects properties that strongly affect speech perception (10–12).Open in a separate windowFig. 1.(A) Schematic representation of the stimuli used for measuring behavioral thresholds. Left and right panels show the stimuli without (MSK) and with (ENH) the precursor, respectively. (B) Left panel shows average thresholds without (MSK) and with (ENH) precursors for Experiments 1 (n = 18) and 2 (n = 16). Right panel shows the amount of enhancement, defined as the difference between the MSK and ENH thresholds, for each experiment. The circles indicate mean thresholds for Experiment 1. The diamonds indicate mean thresholds for Experiment 2. Error bars represent ±1 SEM. (C) Correlations between neural and behavioral enhancement at low- and high-modulation frequencies for Experiments 1 and 2, shown as Pearson''s correlation coefficients (r). The neural enhancement for Experiment 1 was calculated as the average PLV enhancement across the three TMRs.Despite its central role in auditory perception, little is known about the neural mechanisms underlying auditory enhancement. One proposal, known as adaptation of inhibition (6), invokes lateral inhibition between adjacent spectral components (13), comparable to the well-known center-surround receptive fields in the visual system (14) but with the inhibition adapting over time. Thus, when a new spectral component is introduced to an ongoing stimulus, the inhibition from the surrounding components has already adapted, leading to an enhanced representation of the new component. Although this theoretical framework can account for a variety of behavioral results (6–8, 15–19), little evidence exists for its neural implementation. Physiological studies on nonhuman species have found no evidence of enhancement at the level of the auditory nerve (20) but have reported some neural responses consistent with adaptation of inhibition at the level of the inferior colliculus (IC) (21). Taken together, the results suggest hierarchical processing, with enhancement only emerging at the level of the IC. However, such an interpretation must be tempered by the fact that the studies were carried out in different species, only one study was attempted in an awake preparation (21), and none of the studies included behavior. Evidence from human studies remains limited. No evidence for enhancement has been found in the cochlea using otoacoustic emissions (22) or in auditory neural pathways using the 80-Hz auditory steady-state responses (ASSRs) (23). Thus, no neural correlates of auditory enhancement have yet been reported in humans.In the current study, we introduce a method of targeting both subcortical and cortical auditory structures in humans using ASSRs measured with electroencephalography (EEG). We combine a stimulus configuration that produces up to 25-dB behavioral enhancement (8) with a frequency-tagging paradigm, in which the neural responses to both the masker and target components can be distinguished by differences in the amplitude modulation (AM) frequency applied to the target and masker. In Experiment 1, we applied AM to both the target and the masker with two rates to simultaneously record responses, quantified as phase locking values (PLVs) (24), from slower (∼40 Hz) and faster (∼100 Hz) rates that are thought to target primarily cortical and subcortical levels of the auditory pathways, respectively. In Experiment 2, we focused on subcortical responses by using only a single high-modulation frequency, around either 100 or 200 Hz. The EEG responses were measured over a range of target-to-masker ratios (TMRs) that were within the range of the TMRs measured behaviorally at the detection threshold for the same stimuli in the same listeners. Overall, we observed robust correlates of perceptual enhancement in the low-frequency ASSR (∼40 Hz), thought to reflect cortical responses (25–28), but found no correlates of enhancement in the higher-frequency ASSR (100 to 200 Hz), thought to emanate primarily from subcortical sources (29, 30). The pattern of cortical responses was consistent with predictions based on the longstanding, but previously unverified, theory of enhancement based on adaptation of neural inhibition.     

Hypereosinophilia as the presentation of metastatic medullary thyroid carcinoma: a remarkable event

Hypereosinophilic syndrome is a rare disorder characterized by persistent eosinophilia combined with organ system dysfunction. This report is of a 37-year-old man who had eosinophilia, periodic fever, weight loss, and generalized bone pain. A small nodule in left lobe of thyroid was detected in his physical examination. The patient underwent surgery and histopathological study, which confirmed that the patient had medullary carcinoma of thyroid. The patient died 6 months after the surgery. Eosinophilia is more commonly seen with benign conditions. However, less frequent but malignant etiologies always should be contemplated.     

A comparison of three times vs. five times weekly narrowband ultraviolet B phototherapy for the treatment of chronic plaque psoriasis

Background: Narrowband ultraviolet B (NB-UVB) phototherapy is an effective treatment for psoriasis.
Objectives: To compare the effects of three and five times weekly NB-UVB phototherapy in the treatment of chronic plaque psoriasis.
Methods: Sixty-five patients with chronic plaque psoriasis were allocated to receive three or five times weekly NB-UVB, starting at low dose.
Results: Among the patients who completed the study, clearance was achieved in 18 out of 23 patients (78%) in the three times weekly group and in 15 out of 22 patients (68%) in the five times weekly group. The difference was not statistically significant ( P =0.44).
No statistically significant differences were found between the two groups in the number of treatments ( P =0.95), cumulative UVB dose ( P =0.51), and rate of side-effects. Length of the treatment period was significantly shorter in the five times weekly group ( P <0.001). At the end of treatment, the mean psoriasis area and severity index score was lower in the three times weekly group ( P =0.02).
Conclusions: We recommend three times weekly NB-UVB for chronic plaque psoriasis; however, the more rapid clearance of psoriasis with five times weekly phototherapy may justify using this method in some patients.