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<abstract> <p>Fish is a key component of Nigeria's protein supply, making up about 40% of the nation's protein intake and considerably aiding in the achievement of the second Sustainable Development Goal of feeding the expanding population. Despite its importance, Nigeria's fish production and supply cannot keep up with demand. While total fish output has increased from 1,073,059 tonnes in 2014 to 1,169,000 tonnes in 2018 and is expected to reach 1,275,000 tonnes by 2030, there is a great supply gap. Fish production not only affects food security but also the national economy and employment. Notwithstanding, the fisheries sub-sector suffers several difficulties, such as poor management, a deficient fisheries policy, overfishing, diminishing catch, and a lack of technical know-how among fish growers and fishermen. Thus, exploring untapped aquaculture potential and managing small-scale fisheries effectively are necessary to close the gap between the demand for and supply of fish. The fish output situation can be improved by enforcing fisheries policy and regulations, increasing investments in ethical fisheries and aquaculture, and providing sufficient training for fish farmers and fisherfolk. To reduce waste associated with the limited number of fish now produced, post-harvest losses must also be addressed. By solving these issues and putting in place the necessary actions, Nigeria can increase its fish production, strengthen its food security, and accomplish the sustainable development goals in its evolving blue economy.</p> </abstract>

Monitoring progress in the Glasgow 'Declaration on Forests' remains impossible without open sharing of data. Three actions are required if this declaration is to succeed.

AbstractAimsTo establish which components of energy balance mediate the clinically significant weight loss demonstrated with use of cotadutide, a glucagon‐like peptide‐1 (GLP‐1)/glucagon receptor dual agonist, in early‐phase studies.Materials and MethodsWe conducted a phase 2a, single‐centre, randomized, placebo‐controlled trial in overweight and obese adults with type 2 diabetes. Following a 16‐day single‐blind placebo run‐in, participants were randomized 2:1 to double‐blind 42‐day subcutaneous treatment with cotadutide (100–300 μg daily) or placebo. The primary outcome was percentage weight change. Secondary outcomes included change in energy intake (EI) and energy expenditure (EE).ResultsA total of 12 participants (63%) in the cotadutide group and seven (78%) in the placebo group completed the study. The mean (90% confidence interval [CI]) weight change was −4.0% (−4.9%, −3.1%) and −1.4% (−2.7%, −0.1%) for the cotadutide and placebo groups, respectively (p = 0.011). EI was lower with cotadutide versus placebo (−41.3% [−66.7, −15.9]; p = 0.011). Difference in EE (per kJ/kg lean body mass) for cotadutide versus placebo was 1.0% (90% CI −8.4, 10.4; p = 0.784), assessed by doubly labelled water, and −6.5% (90% CI −9.3, −3.7; p < 0.001), assessed by indirect calorimetry.ConclusionWeight loss with cotadutide is primarily driven by reduced EI, with relatively small compensatory changes in EE.

AbstractEcological niche models (ENMs) have classically operated under the simplifying assumptions that there are no barriers to gene flow, species are genetically homogeneous (i.e., no population‐specific local adaptation), and all individuals share the same niche. Yet, these assumptions are violated for most broadly distributed species. Here, we incorporate genetic data from the widespread riparian tree species narrowleaf cottonwood (Populus angustifolia) to examine whether including intraspecific genetic variation can alter model performance and predictions of climate change impacts. We found that (1) P. angustifolia is differentiated into six genetic groups across its range from México to Canada and (2) different populations occupy distinct climate niches representing unique ecotypes. Comparing model discriminatory power, (3) all genetically informed ecological niche models (gENMs) outperformed the standard species‐level ENM (3–14% increase in AUC; 1–23% increase in pROC). Furthermore, (4) gENMs predicted large differences among ecotypes in both the direction and magnitude of responses to climate change and (5) revealed evidence of niche divergence, particularly for the Eastern Rocky Mountain ecotype. (6) Models also predicted progressively increasing fragmentation and decreasing overlap between ecotypes. Contact zones are often hotspots of diversity that are critical for supporting species' capacity to respond to present and future climate change, thus predicted reductions in connectivity among ecotypes is of conservation concern. We further examined the generality of our findings by comparing our model developed for a higher elevation Rocky Mountain species with a related desert riparian cottonwood, P. fremontii. Together our results suggest that incorporating intraspecific genetic information can improve model performance by addressing this important source of variance. gENMs bring an evolutionary perspective to niche modeling and provide a truly “adaptive management” approach to support conservation genetic management of species facing global change.

Pour répondre aux demandes énergétiques d'une population croissante et atténuer les émissions de carbone, il est impératif de passer des combustibles fossiles aux sources d'énergie renouvelables. Cependant, l'intermittence des énergies renouvelables pose un défi important. Pour résoudre ce problème, les aquifères salins profonds sont apparus comme une option viable pour le stockage d'énergie à grande échelle, en particulier grâce au stockage de l'hydrogène (H2) après le processus Power-to-Gas. De plus, les émissions naturelles de H2 ont été documentées dans le monde entier, et le potentiel d'accumulations souterraines présente des sources d'énergie zéro carbone prometteuses. Cependant, dans ces différents contextes, l'interaction entre le gaz, la saumure et la roche peut conduire à des phénomènes physico-chimiques et biochimiques qui peuvent avoir un impact direct sur la mobilité et la stabilité de H2. Par conséquent, la compréhension du comportement thermophysique des fluides impliqués est essentielle pour le développement du stockage souterrain d'hydrogène dans des milieux poreux et pour l'exploration des réserves naturelles de H2. Cependant, malgré les progrès récents, il existe encore un manque de données expérimentales sur les propriétés thermophysiques de l'hydrogène au contact de la saumure. Cette étude étudie l'équilibre du système H2/saumure en utilisant la simulation moléculaire de Monte Carlo à composante fractionnaire continue à travers deux méthodes : la méthode de l'ensemble de Gibbs et la simulation isobare-isotherme basée sur la loi de Henry. Différents champs de force pour les ions H2, eau et sel (NaCl) ont été évalués. Grâce à une analyse comparative, deux combinaisons de modèles, Marx-TIP4P/EP-KBF et Marx-TIP4P/2005-Madrid, ont été identifiées comme fournissant les résultats les plus précis, mais nécessitant une interaction binaire constante pour une quantification améliorée de la solubilité de l'H2 dans la saumure. Après ajustement à certaines données expérimentales limitées de la littérature, les simulations ont été étendues à des températures plus élevées (jusqu'à 453 K), à des pressions (jusqu'à 100 MPa) et à des salinités de NaCl (jusqu'à 6 mol/kgw). Enfin, les données nouvellement générées ont facilité le raffinement d'un modèle thermodynamique en utilisant l'approche de Krichevsky et Kasarnovsky, améliorant les estimations des pertes de dissolution de H2, la capacité d'étanchéité du caprock et les informations sur la production et l'accumulation naturelles de H2 sous terre. Para abordar las demandas energéticas de una población en crecimiento y mitigar las emisiones de carbono, es imperativo pasar de los combustibles fósiles a las fuentes de energía renovables. Sin embargo, la intermitencia de las energías renovables plantea un reto importante. Para abordar este problema, los acuíferos salinos profundos han surgido como una opción viable para el almacenamiento de energía a gran escala, particularmente a través del almacenamiento de hidrógeno (H2) después del proceso Power-to-Gas. Además, las emisiones naturales de H2 se han documentado en todo el mundo, y el potencial de acumulaciones subterráneas presenta fuentes de energía prometedoras sin carbono. Sin embargo, en estos diferentes contextos, la interacción entre el gas, la salmuera y la roca puede conducir a fenómenos físico-químicos y bioquímicos que pueden afectar directamente la movilidad y la estabilidad del H2. Por lo tanto, comprender el comportamiento termofísico de los fluidos involucrados es esencial para el desarrollo del Almacenamiento Subterráneo de Hidrógeno en medios porosos y para explorar las reservas naturales de H2. Sin embargo, a pesar de los avances recientes, todavía hay una falta de datos experimentales sobre las propiedades termofísicas del hidrógeno en contacto con la salmuera. Este estudio investiga el equilibrio del sistema H2/salmuera utilizando la simulación molecular del Componente Fraccionario Continuo Monte Carlo a través de dos métodos: el método del conjunto de Gibbs y la simulación isobárica-isotérmica basada en la ley de Henry. Se evaluaron diferentes campos de fuerza para iones H2, agua y sal (NaCl). A través de un análisis comparativo, se identificaron dos combinaciones de modelos, Marx-TIP4P/EP-KBF y Marx-TIP4P/2005-Madrid, que proporcionan los resultados más precisos, aunque requieren una interacción binaria constante para una cuantificación mejorada de la solubilidad de H2 en salmuera. Después de ajustar algunos datos experimentales limitados de la literatura, las simulaciones se extendieron a temperaturas más altas (hasta 453 K), presiones (hasta 100 MPa) y salinidades de NaCl (hasta 6 mol/kgw). Finalmente, los datos recién generados facilitaron el refinamiento de un modelo termodinámico utilizando el enfoque de Krichevsky y Kasarnovsky, mejorando las estimaciones de las pérdidas de disolución de H2, la capacidad de sellado de caprock y los conocimientos sobre la producción y acumulación natural de H2 bajo tierra. To address the energy demands of a growing population and mitigate carbon emissions, it is imperative to transition from fossil fuels to renewable energy sources. However, the intermittency of renewable energies poses a significant challenge. To address this issue, deep saline aquifers have emerged as a viable option for large-scale energy storage, particularly through hydrogen (H2) storage post Power-to-Gas process. Moreover, natural H2 emissions have been documented worldwide, and the potential for underground accumulations presents promising zero-carbon energy sources. However, in these different contexts, the interaction between gas, brine, and rock can lead to physico-chemical and biochemical phenomena that can directly impact the mobility and stability of H2. Therefore, understanding the thermophysical behavior of the involved fluids is essential for the development Underground Hydrogen Storage in porous media and for exploring natural H2 reserves. However, despite recent advancements, there is still a lack of experimental data on thermophysical properties of hydrogen in contact with brine. This study investigates the equilibrium of the H2/brine system using Continuous Fractional Component Monte Carlo molecular simulation through two methods: the Gibbs ensemble method and the isobaric-isothermal simulation based on Henry's law. Different force fields for H2, water and salt (NaCl) ions were evaluated. Through a comparative analysis, two model combinations, Marx-TIP4P/EP-KBF and Marx-TIP4P/2005-Madrid, were identified as providing the most accurate results, albeit requiring a constant binary interaction for enhanced H2 solubility quantification in brine. After adjustment to some limited experimental data from literature, the simulations were extended to higher temperatures (up to 453 K), pressures (up to 100 MPa), and NaCl salinities (up to 6 mol/kgw). Finally, the newly generated data facilitated the refinement of a thermodynamic model using the Krichevsky and Kasarnovsky approach, improving estimations of H2 dissolution losses, caprock sealing capacity, and insights into natural H2 production and accumulation underground. لتلبية متطلبات الطاقة لعدد متزايد من السكان والتخفيف من انبعاثات الكربون، من الضروري الانتقال من الوقود الأحفوري إلى مصادر الطاقة المتجددة. ومع ذلك، فإن انقطاع الطاقات المتجددة يشكل تحديًا كبيرًا. ولمعالجة هذه المشكلة، برزت طبقات المياه الجوفية المالحة العميقة كخيار قابل للتطبيق لتخزين الطاقة على نطاق واسع، لا سيما من خلال تخزين الهيدروجين (H2) بعد عملية تحويل الطاقة إلى غاز. علاوة على ذلك، تم توثيق انبعاثات الهيدروجين الطبيعية في جميع أنحاء العالم، وتوفر إمكانية التراكمات تحت الأرض مصادر طاقة واعدة خالية من الكربون. ومع ذلك، في هذه السياقات المختلفة، يمكن أن يؤدي التفاعل بين الغاز والمحلول الملحي والصخور إلى ظواهر فيزيائية كيميائية وبيوكيميائية يمكن أن تؤثر بشكل مباشر على حركة واستقرار H2. لذلك، فإن فهم السلوك الفيزيائي الحراري للسوائل المعنية أمر ضروري لتطوير تخزين الهيدروجين تحت الأرض في الوسائط المسامية ولاستكشاف احتياطيات الهيدروجين الطبيعية. ومع ذلك، على الرغم من التطورات الأخيرة، لا يزال هناك نقص في البيانات التجريبية حول الخصائص الفيزيائية الحرارية للهيدروجين الملامس للمحلول الملحي. تبحث هذه الدراسة في توازن نظام H2/المحلول الملحي باستخدام المحاكاة الجزيئية للمكون الكسري المستمر مونت كارلو من خلال طريقتين: طريقة جيبس للمجموعة والمحاكاة متساوية الحرارة على أساس قانون هنري. تم تقييم حقول القوة المختلفة لأيونات H2 والماء والملح (NaCl). من خلال التحليل المقارن، تم تحديد مجموعتين من النماذج، وهما Marx - TIP4P/EP - KBF و Marx - TIP4P/2005 - Madrid، على أنهما توفران النتائج الأكثر دقة، وإن كانت تتطلب تفاعلًا ثنائيًا ثابتًا لتعزيز قياس كمية ذوبان H2 في المحلول الملحي. بعد تعديل بعض البيانات التجريبية المحدودة من الأدبيات، تم تمديد المحاكاة إلى درجات حرارة أعلى (تصل إلى 453 كلفن)، وضغوط (تصل إلى 100 ميجا باسكال)، وملوحة كلوريد الصوديوم (تصل إلى 6 مول/كجم). أخيرًا، سهلت البيانات التي تم إنشاؤها حديثًا صقل نموذج ديناميكي حراري باستخدام نهج Krichevsky و Kasarnovsky، مما أدى إلى تحسين تقديرات خسائر ذوبان H2، وقدرة ختم caprock، ورؤى حول إنتاج H2 الطبيعي وتراكمه تحت الأرض.

AbstractRestoring native grassland vegetation can substantially improve ecosystem service outcomes from agricultural watersheds, but profitable pathways are needed to incentivize conversion from conventional crops. Given growing demand for renewable energy, using grassy biomass to produce biofuels provides a potential solution. We assessed the techno‐economic feasibility and life cycle outcomes of a “grass‐to‐gas” pathway that includes harvesting grassy (lignocellulosic) biomass for renewable natural gas (RNG) production through anaerobic digestion (AD), expanding on previous research that quantified ecosystem service and landowner financial outcomes of simulated grassland restoration in the Grand River Basin of Iowa and Missouri, United States. We found that the amount of RNG produced through AD of grassy biomass ranged 0.12–45.04 million gigajoules (GJ), and the net present value (NPV) of the RNG ranged −$97 to $422 million, depending on the combination of land use, productivity, and environmental credit scenarios. Positive NPVs are achieved with environmental credits for replacement of synthetic agricultural inputs with digestate and clean fuel production (e.g., USEPA D3 Renewable Identification Number, California Low Carbon Fuel Standard). Producing RNG from grassy biomass emits 15.1 g CO2‐eq/MJ, which compares favorably to the fossil natural gas value of 61.1 g CO2‐eq/MJ and exceeds the US Environmental Protection Agency's requirement for cellulosic biofuel. Overall, this study demonstrates opportunities and limitations to using grassy biomass from restored grasslands for sustainable RNG production.

AbstractPeatlands are the most efficient natural ecosystems for long‐term storage of atmospheric carbon. Our understanding of peatland carbon cycling is based entirely on bottom‐up controls regulated by low nutrient availability. Recent studies have shown that top‐down controls through predator‐prey dynamics can influence ecosystem function, yet this has not been evaluated in peatlands to date. Here, we used a combination of nutrient enrichment and trophic‐level manipulation to test the hypothesis that interactions between nutrient availability (bottom‐up) and predation (top‐down) influence peatland carbon fluxes. Elevated nutrients stimulated bacterial biomass and organic matter decomposition. In the absence of top‐down regulation, carbon dioxide (CO2) respiration driven by greater decomposition was offset by elevated algal productivity. Herbivores accelerated CO2 emissions by removing algal biomass, while predators indirectly reduced CO2 emissions by muting herbivory in a trophic cascade. This study demonstrates that trophic interactions can mitigate CO2 emissions associated with elevated nutrient levels in northern peatlands.