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"Levy, Samuel"
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Have food supply chain policies improved forest conservation and rural livelihoods? A systematic review
To address concerns about the negative impacts of food supply chains in forest regions, a growing number of companies have adopted policies to influence their suppliers' behaviors. With a focus on forest-risk food supply chains, we provide a systematic review of the conservation and livelihood outcomes of the mechanisms that companies use to implement their forest-focused supply chain policies (FSPs)-certifications, codes of conduct, and market exclusion mechanisms. More than half of the 37 cases that rigorously measure the outcomes of FSP implementation mechanisms find additional conservation and livelihood benefits resulting from the policies. Positive livelihood outcomes are more common than conservation additionality and most often pertain to improvements in farm income through increases in crop yields on coffee and cocoa farms that have adopted certifications or codes of conduct. However, in some cases certifications lead to a reduction in net household income as farmers increasingly specialize in the certified commodity and spend more on food purchases. Among the five cases that examine conservation and livelihoods simultaneously, there is no evidence of tradeoffs or synergies-most often an improvement in one type of outcome is associated with no change in the other. Interactions with public conservation and agricultural policies influence the conservation gains achieved by all mechanisms, while the marketing attributes of cooperatives and buying companies play a large role in determining the livelihood outcomes associated with certification. Compliance with the forest requirements of FSP implementation mechanisms is high, but challenges to geospatial monitoring and land use related selection biases limit the overall benefits of these policies. Given the highly variable methods and limited evidence base, additional rigorous research across a greater variety of contexts is urgently needed to better understand if and when FSPs can be successful in achieving synergies between conservation and livelihoods.
Journal Article
A systematic comparison of deforestation drivers and policy effectiveness across the Amazon biome
The Amazon biome, spanning nine countries, has one of the highest rates of deforestation worldwide. This deforestation contributes to biodiversity loss, climate change, the spread of infectious diseases, and damage to rural and indigenous livelihoods. Hundreds of articles have been published on the topic of deforestation across Amazonia, yet there has been no recent synthesis of deforestation drivers and deforestation-control policy effectiveness in the region. Here we undertook the first systematic review of papers published between 2000 and 2021 that have causally linked proximate and underlying drivers and policies to deforestation outcomes in Amazonia. In the 155 articles that met our inclusion criteria, we find that causal research is concentrated in Brazil, and to a lesser degree Peru, Ecuador, and Bolivia. There has been little study of the Guianas, Venezuela or Colombia. Large- and small-scale agriculture linked to improved market access and high agricultural prices are frequently researched underlying drivers of deforestation across the heavily researched regions. In the Guianas research focuses on mining with little focus on underlying causes. Research on infrastructure expansion, mining, and oil extraction and on technological, sociocultural, and institutional factors remains sparse. Many public and private policies have been found to be effective in controlling deforestation across the biome, with protected areas and public policies standing out as particularly successful in slowing deforestation vis-à-vis supply chain approaches. Frontier age, land tenure, and policy interactions are key moderating factors affecting the outcomes of different underlying causes and policies. Our findings indicate a greater need for research on (i) additional deforestation drivers beyond agriculture and economic factors, (ii) the complex interactions between different drivers and deforestation control policies, (iii) causes underlying deforestation in low or new deforestation areas, and (iv) the dynamics between Amazonian subregions and countries. Understanding the extent and diversity of deforestation drivers and effectiveness of existing deforestation mitigation policies across Amazonia is a necessary first step toward designing policies to further reduce deforestation in the biome.
Journal Article
Detection of early stage pancreatic cancer using 5-hydroxymethylcytosine signatures in circulating cell free DNA
Pancreatic cancer is often detected late, when curative therapies are no longer possible. Here, we present non-invasive detection of pancreatic ductal adenocarcinoma (PDAC) by 5-hydroxymethylcytosine (5hmC) changes in circulating cell free DNA from a PDAC cohort (
n
= 64) in comparison with a non-cancer cohort (
n
= 243). Differential hydroxymethylation is found in thousands of genes, most significantly in genes related to pancreas development or function (
GATA4
,
GATA6
,
PROX1
,
ONECUT1
,
MEIS2
), and cancer pathogenesis (
YAP1
,
TEAD1
,
PROX1
,
IGF1
). cfDNA hydroxymethylome in PDAC cohort is differentially enriched for genes that are commonly de-regulated in PDAC tumors upon activation of
KRAS
and inactivation of
TP53
. Regularized regression models built using 5hmC densities in genes perform with AUC of 0.92 (discovery dataset,
n
= 79) and 0.92–0.94 (two independent test sets,
n
= 228). Furthermore, tissue-derived 5hmC features can be used to classify PDAC cfDNA (AUC = 0.88). These findings suggest that 5hmC changes enable classification of PDAC even during early stage disease.
Circulating DNA detected in plasma can be used for diagnostic purposes. Here, the authors show that the 5-hydroxymethyl cytosine biomarker from plasma-derived cell free DNA can be used to detect early stage pancreatic cancer.
Journal Article
Identifying global hotspots of agricultural expansion into non-forest ecosystems
Ecologically important non-forest ecosystems, including grasslands, shrublands and wetlands, face substantial threats from agricultural expansion, yet their conversion dynamics remain poorly understood. This study identifies global hotspots of land conversion from non-forest (and forest) ecosystems to cultivated lands from 2000 to 2020, including conversion within Protected Areas and its impacts for biodiversity conservation. Using three state-of-the-art land cover datasets (GlobeLand30, GLCLUC and GLC_FCS30D), we find extensive and increasing non-forest conversion, often comparable to or exceeding forest conversion. Protected non-forest ecosystems cover substantially smaller area than protected forests while experiencing disproportionately high conversion rates. Non-forest and forest conversion together affected habitats of over 5,000 threatened species, over half of which depend critically on non-forest ecosystems. Our study provides important insights for improved land cover data development, while offering companies and policymakers science-based evidence to design sustainable land-use policies and integrated policy frameworks that avoid trade-offs and support broad sustainability goals.
This study maps global hotspots of cropland expansion into non-forest ecosystems, revealing extensive conversion inside and outside protected areas that threatens biodiversity and underscores an urgent need for conservation efforts beyond forests.
Journal Article
Trajectory-modulated hippocampal neurons persist throughout memory-guided navigation
Trajectory-dependent splitter neurons in the hippocampus encode information about a rodent’s prior trajectory during performance of a continuous alternation task. As such, they provide valuable information for supporting memory-guided behavior. Here, we employed single-photon calcium imaging in freely moving mice to investigate the emergence and fate of trajectory-dependent activity through learning and mastery of a continuous spatial alternation task. In agreement with others, the quality of trajectory-dependent information in hippocampal neurons correlated with task performance. We thus hypothesized that, due to their utility, splitter neurons would exhibit heightened stability. We find that splitter neurons were more likely to remain active and retained more consistent spatial information across multiple days than other neurons. Furthermore, we find that both splitter neurons and place cells emerged rapidly and maintained stable trajectory-dependent/spatial activity thereafter. Our results suggest that neurons with useful functional coding exhibit heightened stability to support memory guided behavior.
Trajectory-coding neurons in the hippocampus convey important information for performing memory tasks. Here, Kinsky et al. track long-term neural activity in the hippocampus to find that trajectory-coding emerges rapidly and remains stable across long time-scales.
Journal Article
A human tissue map of 5-hydroxymethylcytosines exhibits tissue specificity through gene and enhancer modulation
DNA 5-hydroxymethylcytosine (5hmC) modification is known to be associated with gene transcription and frequently used as a mark to investigate dynamic DNA methylation conversion during mammalian development and in human diseases. However, the lack of genome-wide 5hmC profiles in different human tissue types impedes drawing generalized conclusions about how 5hmC is implicated in transcription activity and tissue specificity. To meet this need, we describe the development of a 5hmC tissue map by characterizing the genomic distributions of 5hmC in 19 human tissues derived from ten organ systems. Subsequent sequencing results enabled the identification of genome-wide 5hmC distributions that uniquely separates samples by tissue type. Further comparison of the 5hmC profiles with transcriptomes and histone modifications revealed that 5hmC is preferentially enriched on tissue-specific gene bodies and enhancers. Taken together, the results provide an extensive 5hmC map across diverse human tissue types that suggests a potential role of 5hmC in tissue-specific development; as well as a resource to facilitate future studies of DNA demethylation in pathogenesis and the development of 5hmC as biomarkers.
DNA 5-hydroxymethylcytosine (5hmC) modification is associated with gene transcription and used as a mark of mammalian development. Here the authors report a comprehensive 5hmC tissue map and analysis of 5hmC genomic distributions in 19 human tissues derived from 10 organ systems, thus providing insights into the role of 5hmC in tissue-specific development.
Journal Article
Increased Mortality after Dronedarone Therapy for Severe Heart Failure
Dronedarone is a class III antiarrhythmic drug that has efficacy as a treatment for atrial fibrillation and ventricular arrhythmias. In this clinical trial involving patients with severe heart failure, however, dronedarone was found to increase overall mortality, raising serious concern about the safety of this drug in patients with advanced heart failure.
In patients with severe heart failure, dronedarone was found to increase overall mortality, raising serious concern about the safety of this drug in patients with advanced heart failure.
Atrial and ventricular arrhythmias contribute to the morbidity and mortality associated with heart failure.
1
–
3
Class III antiarrhythmic agents reduce the likelihood of the development of atrial fibrillation in patients with heart failure and also increase the rate of conversion from atrial fibrillation to sinus rhythm, which may reduce the risk of acute decompensation. In a previous randomized trial involving patients with heart failure, use of one agent in this class, dofetilide, was associated with fewer hospitalizations for worsening heart failure.
4
Ventricular arrhythmias are also common in patients with heart failure and reduced systolic function and frequently lead to sudden . . .
Journal Article
An investigation of SMART Recovery: protocol for a longitudinal cohort study of individuals making a new recovery attempt from alcohol use disorder
IntroductionAlcohol use disorder (AUD) remains one of the most pervasive of all psychiatric illnesses conferring a massive health and economic burden. In addition to professional treatments to address AUD, mutual-help organisations such as Alcoholics Anonymous (AA) and newer entities like Self-Management and Recovery Training (SMART Recovery) play increasingly important roles in many societies. While much is known about the positive effects of AA, very little is known about SMART. Hence, this study seeks to estimate real-world patterns of utilisation and benefit from SMART Recovery as well as explore for whom (moderators) and how (mechanisms) SMART confers recovery benefits.Methods and analysisNaturalistic, longitudinal, cohort study (n=368) of individuals with AUD recruited between February 2019 and February 2022, initiating a new recovery attempt who self-select into one of four groups at study entry: (1) SMART Recovery; (2) AA; (3) SMART+AA; (4) Neither SMART nor AA; (stratified by Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM 5) severity markers), with assessments conducted at intake, and 3 months, 6 months, 9 months, 12 months, 18 months and 24 months. Primary outcomes are: frequency of SMART and AA meetings attendance; per cent days abstinent and per cent days heavy drinking. Secondary outcomes include psychiatric distress; quality of life and functioning. Moderator variables include sex/gender; race/ethnicity; spirituality. Mediational variables include social networks; coping skills; self-efficacy; impulsivity. Multivariable regression with propensity score matching will test for patterns of attendance and effects of participation over time on outcomes and test for mechanisms and moderators.Ethics and disseminationThis study involves human participants and was approved by the Massachusetts General Hospital Institutional Review Board (Protocol #: 2017P002029/PHS). Results will be published in peer-reviewed journals and presented at conferences.RegistrationThis is a non-randomised, naturalistic, longitudinal, cohort study, and thus was not registered in advance. Results, therefore, should be considered exploratory.
Journal Article
Fast-growing pioneer tree stands as a rapid and effective strategy for bracken elimination in the Neotropics
1. Large areas of agricultural land around the world are degraded as a consequence of dominance by bracken fern (Pteridium spp.). Tropical production systems based on shifting cultivation and cattle breeding are particularly vulnerable to invasion of this species. In spite of this, effective methods for tropical bracken control are limited. 2. Fast-growing tree species have been used successfully to out-compete aggressively colonizing heliophytes and trigger natural succession. Drawing on a traditional Mayan management technique, we evaluate the potential of the pioneer tree balsa (Ochroma pyramidale) to control Pteridium caudatum in Chiapas, Mexico. We tested different bracken cutting frequencies and balsa propagation methods in a factorial randomized block experiment. Eighteen months later, we quantified bracken biomass under the young balsa canopy. 3. Living bracken rhizome biomass correlated significantly with balsa basal area, leaf litter biomass and understorey light intensity. While bracken rhizomes persisted in control plots, it was completely eradicated in plots with a minimum balsa basal area of 11 m² ha⁻¹. This threshold value was reached in less than 18 months with any of the tested propagation methods (seed broadcasting, direct sowing or nursery seedlings), on the condition of at least monthly bracken cutting during the first six months. 4. The ability of fast-growing broad-leaved pioneer trees like balsa to quickly out-compete bracken fern offers opportunities for large-scale application in tropical rural areas where economic and technical resources are scarce. 5. Synthesis and applications. Mayan subsistence farmers traditionally use balsa to outcompete invasive weeds, including bracken fern. Here, we highlight the usefulness of this method for quick and effective bracken control in southern Mexico. This approach, in combination with balsa's short rotation cycle, creates opportunities to rapidly convert bracken land into forest stands with commercial potential, thus providing local income and increasing the likelihood of adoption by rural people. We encourage further research to test the potential of balsa and other fast-growing pioneer trees species for controlling bracken and similar weeds.
Journal Article