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Carboxylic acids are a small but essential compound class within petroleum chemistry, influencing crude oil behaviors in production and processing and causing environmental impacts. Detailed structural information is fundamental to understanding their influence on petroleum characteristics. However, characterizing acids in crude oil remains challenging due to matrix effects, structural diversity, and low abundance. In this work, we present a new methodology for profiling carboxylic acids by liquid-liquid extraction and selective derivatization using 4-bromo-N-methylbenzylamine (4-BNMA) followed by liquid chromatography and electrospray ionization Orbitrap mass spectrometry (LC-ESI-Orbitrap MS). The fragmentation of 4-BNMA derivatives produces a unique product ion pair, m/z 169/171, enabling the identification of chromatographic fractions containing carboxylic acids. The mass spectra of the corresponding fractions are extracted, and the acids are further computationally isolated based on the isotopic pattern. The method was optimized and validated using acid standards and systematic experimental designs, assuring robustness and sensitivity for nontarget screening purposes. This method detected up to 380 carboxylic acids in six Danish North Sea crude oils, with up to two carboxyl and other heteroatom functionalities (NSO). The results indicated that the most populated species are fatty acids (double bond equivalent (DBE) = 1) and small aromatic acids (DBE = 2-6). The predominance and diversities of compound classes in different samples are consistent with their corresponding bulk properties. Polyfunctional acids (Ox, NxOx, and SxOx) were observed due to exposure to oxidation and biodegradation. Also, the approach's applicability benefits high-resolution MS analysis by simplifying data processing for crude oil and potentially other high-organic and aqueous samples.
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The detection of methane and carbon dioxide is of growing importance due to their negative impact on global warming. This is true for both environmental monitoring and leak detection in industrial processes. Although solid-state sensors are technologically mature, they have limitations that prohibit their use in certain situations, e.g., explosive atmospheres. Thus, there is a need to develop new types of sensor materials. Herein, we demonstrate a simple, low-cost, metal-organic framework (MOF)-based gas leak detection sensor. The system is based on gravimetric sensing by using a quartz crystal microbalance. The quartz crystal is functionalized by layer-by-layer growth of a thin metal-organic framework film. This film shows selective uptake of methane or carbon dioxide under atmospheric conditions. The hardware has low cost, simple operation, and theoretically high sensitivity. Overall, the sensor is characterized by simplicity and high robustness. Furthermore, by exploiting the different adsorption kinetics as measured by multiple harmonic analyses, it is possible to discriminate whether the response is due to methane or carbon dioxide. In summary, we demonstrate data relevant toward new applications of metal-organic frameworks and microporous hybrid materials in sensing.
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Dióxido de Carbono , Estructuras Metalorgánicas , Temperatura , Adsorción , MetanoRESUMEN
Conventional desalination membrane technologies, although offer portable drinking water, are still energy-intensive processes. This paper proposes a potentially new approach for performing water desalination and purification by utilizing the reversible interaction of carbon dioxide (CO2) with nucleophilic aminesâreminiscent of the Solvay process. Based on our model studies with small molecules, CO2-responsive amphiphilic insoluble diamines were prepared, characterized, and applied in the formation of soda and ammonium chloride upon exposure to ambient CO2 (1 atm), thus removing chloride ions from model and real seawater. This ion-exchange process and separation of chloride from the aqueous phase are spontaneous in the presence of CO2 without the need for external energy sources. We demonstrate a flow system to envisage energy-efficient CO2-mediated desalination and simultaneous carbon capture and sequestration.
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Density-dependent prey depletion around breeding colonies has long been considered an important factor controlling the population dynamics of colonial animals.1-4 Ashmole proposed that as seabird colony size increases, intraspecific competition leads to declines in reproductive success, as breeding adults must spend more time and energy to find prey farther from the colony.1 Seabird colony size often varies over several orders of magnitude within the same species and can include millions of individuals per colony.5,6 As such, colony size likely plays an important role in determining the individual behavior of its members and how the colony interacts with the surrounding environment.6 Using tracking data from murres (Uria spp.), the world's most densely breeding seabirds, we show that the distribution of foraging-trip distances scales to colony size0.33 during the chick-rearing stage, consistent with Ashmole's halo theory.1,2 This pattern occurred across colonies varying in size over three orders of magnitude and distributed throughout the North Atlantic region. The strong relationship between colony size and foraging range means that the foraging areas of some colonial species can be estimated from colony sizes, which is more practical to measure over a large geographic scale. Two-thirds of the North Atlantic murre population breed at the 16 largest colonies; by extrapolating the predicted foraging ranges to sites without tracking data, we show that only two of these large colonies have significant coverage as marine protected areas. Our results are an important example of how theoretical models, in this case, Ashmole's version of central-place-foraging theory, can be applied to inform conservation and management in colonial breeding species.
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Charadriiformes , Animales , Ecosistema , Dinámica Poblacional , ReproducciónRESUMEN
Timing of breeding, an important driver of fitness in many populations, is widely studied in the context of global change, yet despite considerable efforts to identify environmental drivers of seabird nesting phenology, for most populations we lack evidence of strong drivers. Here we adopt an alternative approach, examining the degree to which different populations positively covary in their annual phenology to infer whether phenological responses to environmental drivers are likely to be (a) shared across species at a range of spatial scales, (b) shared across populations of a species or (c) idiosyncratic to populations. We combined 51 long-term datasets on breeding phenology spanning 50 years from nine seabird species across 29 North Atlantic sites and examined the extent to which different populations share early versus late breeding seasons depending on a hierarchy of spatial scales comprising breeding site, small-scale region, large-scale region and the whole North Atlantic. In about a third of cases, we found laying dates of populations of different species sharing the same breeding site or small-scale breeding region were positively correlated, which is consistent with the hypothesis that they share phenological responses to the same environmental conditions. In comparison, we found no evidence for positive phenological covariation among populations across species aggregated at larger spatial scales. In general, we found little evidence for positive phenological covariation between populations of a single species, and in many instances the inter-year variation specific to a population was substantial, consistent with each population responding idiosyncratically to local environmental conditions. Black-legged kittiwake Rissa tridactyla was the exception, with populations exhibiting positive covariation in laying dates that decayed with the distance between breeding sites, suggesting that populations may be responding to a similar driver. Our approach sheds light on the potential factors that may drive phenology in our study species, thus furthering our understanding of the scales at which different seabirds interact with interannual variation in their environment. We also identify additional systems and phenological questions to which our inferential approach could be applied.
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Charadriiformes , Animales , Cambio Climático , Estaciones del AñoRESUMEN
The discharge of produced water from offshore oil platforms is an emerging concern due to its potential adverse effects on marine ecosystems. In this study, we investigated the feasibility and capability of using marine sediments for the bioremediation of produced water. We utilized a combination of porewater and solid phase analysis in a series of sediment batch incubations amended with produced water and synthetic produced water to determine the biodegradation of hydrocarbons under different redox conditions. Significant removal of benzene, toluene, ethylbenzene and xylene (BTEX) compounds was observed under different redox conditions, with biodegradation efficiencies of 93-97% in oxic incubations and 45-93% in anoxic incubations with nitrate, iron oxide or sulfate as the electron acceptor. Higher biodegradation rates of BTEX were obtained by incubations dominated by nitrate reduction (104-149 nmolC/cm3/d) and oxygen respiration (52-57 nmolC/cm3/d), followed by sulfate reduction (14-76 nmolC/cm3/d) and iron reduction (29-39 nmolC/cm3/d). Chemical fingerprint analysis showed that hydrocarbons were biodegraded to smaller alcohols/acids under oxic conditions compared to anoxic conditions with nitrate, indicating that the presence of oxygen facilitated a more complete biodegradation process. Toxicity of treated produced water to the marine copepod Acartia tonsa was reduced by half after sediment incubations with oxygen and nitrate. Our study emphasizes the possibility to use marine sediment as a biofilter for treating produced water at sea without extending the oil and gas platform or implementing a large-scale construction.
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Nitratos , Contaminantes Químicos del Agua , Benceno/metabolismo , Biodegradación Ambiental , Ecosistema , Sedimentos Geológicos/química , Hidrocarburos/análisis , Nitratos/análisis , Oxidación-Reducción , Oxígeno/análisis , Sulfatos/química , Tolueno/metabolismo , Agua/análisis , Contaminantes Químicos del Agua/análisis , Xilenos/metabolismoRESUMEN
The retreating ice cover of the Central Arctic Ocean (CAO) fuels speculations on future fisheries. However, very little is known about the existence of harvestable fish stocks in this 3.3 million-square kilometer ecosystem around the North Pole. Crossing the Eurasian Basin, we documented an uninterrupted 3170-kilometer-long deep scattering layer (DSL) with zooplankton and small fish in the Atlantic water layer at 100- to 500-meter depth. Diel vertical migration of this central Arctic DSL was lacking most of the year when daily light variation was absent. Unexpectedly, the DSL also contained low abundances of Atlantic cod, along with lanternfish, armhook squid, and Arctic endemic ice cod. The Atlantic cod originated from Norwegian spawning grounds and had lived in Arctic water temperature for up to 6 years. The potential fish abundance was far below commercially sustainable levels and is expected to remain so because of the low productivity of the CAO.
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Oral leukoplakia (OL), a potentially malignant disorder, recurs in 40% of cases after surgical removal. Recurrence is a risk factor for malignant transformation. We aimed to examine the prognostic significance of four biomarkers related to cell proliferation: p53, p63, podoplanin (PDPN) and Ki-67 in predicting recurrence. Formalin-fixed-paraffin-embedded specimens from excised OL (n = 73, 33 recurrent; 40 non-recurrent) were collected in a prospective study. Immunohistochemistry was used to visualise expression of p53, p63, PDPN and Ki-67. Image analysis software was used for quantification of p53-, p63- and Ki-67-expressing cells, while PDPN was analysed visually. The expression of all four proteins were higher in recurrent compared with non-recurrent OL, only expression of p53 was statistically significant. In uni- and multivariable Cox regression analyses of individual markers, expression of p63 was significantly associated with higher recurrence risk (p = 0.047). OL with a combined high expression of both p53 and p63 had a significantly higher risk to recur [Log Rank, p = 0.036; multivariate Cox, HR: 2.48 (1.13-5.44; p = 0.024)]. Combination of p53 and p63 expression may be used as a prognostic biomarker for recurrence of OL.
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Antígeno Ki-67/metabolismo , Leucoplasia Bucal/metabolismo , Glicoproteínas de Membrana/metabolismo , Factores de Transcripción/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/metabolismo , Proliferación Celular , Femenino , Humanos , Leucoplasia Bucal/patología , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia , Transducción de SeñalRESUMEN
OBJECTIVES: Although causal associations between oral leukoplakia (OL), oral squamous cell carcinoma (OSCC) and high-risk human papillomavirus (HR-HPV) have been speculated upon in several reports, conclusive evidence has not been presented. This study investigates whether the number of cases of HR-HPV in OL has increased over time and whether the prevalence of HR-HPV-positive OL differs in various parts of the world. PATIENTS AND METHODS: A total of 432 patients with OL from Sweden, Brazil and Romania were analysed. Patients were divided into historical (1992-2002) and contemporary (2011-2017) cohorts from the respective countries. Seventeen patients with OL developed oral squamous cell carcinoma (OSCC). A real-time PCR assay, targeting HPV sub-types 6,11,16,18,31,33,35,39,45,52,56,58 and 59, was performed to detect HR-HPV in patients with OL. RESULTS: In the Swedish and Romanian cohorts, none of the investigated HPV sub-types were detected. In the Brazilian cohorts, five patients with OL (3%) were positive for HR-HPV, including four patients from the contemporary cohort (HPV 16, 31, 33) and one from the historical cohort (HPV 11). All the cases of OL that transformed into OSCC were HR-HPV-negative, as were the corresponding tumours. CONCLUSIONS: In summary, the prevalence of HR-HPV in OL is low in all the tested countries, and the incidence has not changed over time. HR-HPV in OL does not seem to be a driver of oncogenesis.
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Carcinoma de Células Escamosas , Neoplasias de Cabeza y Cuello , Neoplasias de la Boca , Papillomaviridae , Infecciones por Papillomavirus , Brasil/epidemiología , Carcinoma de Células Escamosas/epidemiología , ADN Viral , Humanos , Leucoplasia Bucal/epidemiología , Neoplasias de la Boca/epidemiología , Papillomaviridae/genética , Infecciones por Papillomavirus/complicaciones , Infecciones por Papillomavirus/epidemiología , Rumanía/epidemiología , Carcinoma de Células Escamosas de Cabeza y Cuello , Suecia/epidemiologíaRESUMEN
The widespread lockdowns put in place to limit the spread of the new coronavirus disease (COVID-19) offers a rare opportunity in understanding how human presence influence ecosystems. Using data from long-term seabird monitoring, we reveal a previously concealed guarding effect by tourist groups on an iconic seabird colony in the Baltic Sea. The absence of tourists in 2020 lead to a sevenfold increase in presence of white-tailed eagles Haliaeetus albicilla, a sevenfold increase in their disturbance of breeding common murres Uria aalge and causing 26% lower murre productivity than the long-term average. Eagles did not prey on murres, but their frequent disturbances delayed egg laying and facilitated egg predation from herring gulls Larus argentatus and hooded crows Corvus cornix. Based on our findings, we suggest that human presence could be used as a strategic measure in guarding seabird colonies, and that a social-ecological systems perspective is vital for long-term success in protected area management.
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Spring migration phenology is shifting towards earlier dates as a response to climate change in many bird species. However, the patterns of change might not be the same for all species, populations, sex and age classes. In particular, patterns of change could differ between species with different ecology. We analyzed 18 years of standardized bird capture data at a spring stopover site on the island of Ponza, Italy, to determine species-specific rates of phenological change for 30 species following the crossing of the Mediterranean Sea. The advancement of spring passage was more pronounced in species wintering in Northern Africa (i.e. short-distance migrants) and in the Sahel zone. Only males from species wintering further South in the forests of central Africa advanced their passage, with no effect on the overall peak date of passage of the species. The migration window on Ponza broadened in many species, suggesting that early migrants within a species are advancing their migration more than late migrants. These data suggest that the cues available to the birds to adjust departure might be changing at different rates depending on wintering location and habitat, or that early migrants of different species might be responding differently to changing conditions along the route. However, more data on departure time from the wintering areas are required to understand the mechanisms underlying such phenological changes.
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Migración Animal/fisiología , Aves/fisiología , África , Animales , Cambio Climático , Femenino , Italia , Masculino , Mar Mediterráneo , Estaciones del Año , Análisis Espacio-Temporal , Especificidad de la EspecieRESUMEN
Oral leukoplakia (OL) is a potentially malignant oral disorder. The Gold Standard treatment is to remove surgically the OL. Despite optimal surgery, the recurrence rates are estimated to be 30%. The reason for this is unknown. The aim of this study was to investigate the clinical factors that correlate with recurrence after surgical removal of OL. In a prospective study data were collected from 226 patients with OL. Forty-six patients were excluded due to incomplete records or concomitant presence of other oral mucosal diseases. Overall, 180 patients proceeded to analysis (94 women and 86 men; mean age, 62 years; age range, 28-92 years). Clinical data, such as gender, diagnosis (homogeneous/non-homogeneous leukoplakia), location, size, tobacco and alcohol use, verified histopathological diagnosis, and clinical photograph, were obtained. In patients who were eligible for surgery, the OL was surgically removed with a margin. To establish recurrence, a healthy mucosa between the surgery and recurrence had to be confirmed in the records or clinical photographs. Statistical analysis was performed with the level of significance set at P<0.05. Of the 180 patients diagnosed with OL, 57% (N = 103) underwent surgical removal in toto. Recurrence was observed in 43 OL. The cumulative incidence of recurrence of OL was 45% after 4 years and 49% after 5 years. Fifty-six percent (N = 23) of the non-homogeneous type recurred. Among snuff-users 73% (N = 8) cases of OL recurred. A non-homogeneous type of OL and the use of snuff were significantly associated with recurrence after surgical excision (P = 0.021 and P = 0.003, respectively). Recurrence was also significantly associated with cancer transformation (P<0.001). No significant differences were found between recurrence and any of the following: dysplasia, site of lesion, size, multiple vs. solitary OL, gender, age, use of alcohol or smoking. In conclusion, clinical factors that predict recurrence of OL are non-homogeneous type and use of snuff.
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Transformación Celular Neoplásica/patología , Leucoplasia Bucal/cirugía , Mucosa Bucal/patología , Recurrencia Local de Neoplasia/epidemiología , Procedimientos Quirúrgicos Orales , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Leucoplasia Bucal/epidemiología , Leucoplasia Bucal/etiología , Leucoplasia Bucal/patología , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/etiología , Recurrencia Local de Neoplasia/patología , Recurrencia Local de Neoplasia/prevención & control , Estudios Prospectivos , Factores de Riesgo , Tabaco sin Humo/efectos adversos , Resultado del Tratamiento , Adulto JovenRESUMEN
BACKGROUND: Oral leukoplakia (OL) is a potentially malignant oral mucosal disorder. A casual association between OL, oral squamous cell carcinoma (OSCC) and human papillomavirus (HPV) infection has been suggested, but no conclusive evidence has been presented. p16, a tumour-suppressor protein, is used as a surrogate marker for HPV infection. The aim of this study was to investigate how overexpression of p16 correlates with HPV infection in OL and in OSCC. PATIENTS AND METHODS: Seventy-four patients with OL and 13 with OSCC with p16 overexpressed, were analyzed by immunohistochemistry visualizing p16 and a real-time polymerase chain reaction (PCR) assay targeting HPV types 6, 11, 16, 18, 31, 33, 35, 39, 45, 52, 56, 58 and 59. RESULTS: Overexpression of p16 was observed in 18% of patients with OL. None of the HPV subtypes were detected by PCR analysis in patients with OL. In the p16-positive OSCC specimens, 38% were also HPV16-positive. CONCLUSION: Overexpression of p16 was not found to be a reliable biomarker for HPV infection in patients with OL and OSCC.
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Carcinoma de Células Escamosas , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Leucoplasia Bucal , Neoplasias de la Boca , Papillomaviridae , Infecciones por Papillomavirus , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/virología , ADN Viral/análisis , Femenino , Humanos , Leucoplasia Bucal/metabolismo , Leucoplasia Bucal/virología , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/metabolismo , Neoplasias de la Boca/virología , Papillomaviridae/genética , Infecciones por Papillomavirus/metabolismo , Infecciones por Papillomavirus/virologíaRESUMEN
The establishment of interdisciplinary Master's and PhD programs in sustainability science is opening up an exciting arena filled with opportunities for early-career scholars to address pressing sustainability challenges. However, embarking upon an interdisciplinary endeavor as an early-career scholar poses a unique set of challenges: to develop an individual scientific identity and a strong and specific methodological skill-set, while at the same time gaining the ability to understand and communicate between different epistemologies. Here, we explore the challenges and opportunities that emerge from a new kind of interdisciplinary journey, which we describe as 'undisciplinary.' Undisciplinary describes (1) the space or condition of early-career researchers with early interdisciplinary backgrounds, (2) the process of the journey, and (3) the orientation which aids scholars to address the complex nature of today's sustainability challenges. The undisciplinary journey is an iterative and reflexive process of balancing methodological groundedness and epistemological agility to engage in rigorous sustainability science. The paper draws upon insights from a collective journey of broad discussion, reflection, and learning, including a survey on educational backgrounds of different generations of sustainability scholars, participatory forum theater, and a panel discussion at the Resilience 2014 conference (Montpellier, France). Based on the results from this diversity of methods, we suggest that there is now a new and distinct generation of sustainability scholars that start their careers with interdisciplinary training, as opposed to only engaging in interdisciplinary research once strong disciplinary foundations have been built. We further identify methodological groundedness and epistemological agility as guiding competencies to become capable sustainability scientists and discuss the implications of an undisciplinary journey in the current institutional context of universities and research centers. In this paper, we propose a simple framework to help early-career sustainability scholars and well-established scientists successfully navigate what can sometimes be an uncomfortable space in education and research, with the ultimate aim of producing and engaging in rigorous and impactful sustainability science.
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We present a straightforward and robust method for simultaneous quantification of succinylacetone and nitisinone in plasma using LC-ESI-MS/MS. The method has been developed for routine therapeutic drug monitoring in hepatorenal tyrosinemia type 1 (HT1) patients undergoing nitisinone treatment. Previous methods are based on separate analyses of succinylacetone and nitisinone, often using the potentially harmful compound hydrazine for derivatization of the former. In the present procedure, succinylacetone is derivatized in a single-step using butanolic HCl. Analyte extraction and sample clean-up is carried out by simple protein precipitation. The linear range for both analytes is 0.1 up to 125µM, covering the vast majority of encountered levels in real-life samples. The sensitivity and limit of quantification allows measurement of succinylacetone in the therapeutical range for HT1 patients. Stability studies show that succinylacetone is highly sensitive to storage conditions, whereas nitisinone shows little to no degradation. Correct sample handling is therefore important for reliable results when monitoring succinylacetone concentrations.
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Ciclohexanonas/sangre , Monitoreo de Drogas/métodos , Heptanoatos/sangre , Nitrobenzoatos/sangre , Tirosinemias/tratamiento farmacológico , Cromatografía Liquida/métodos , Ciclohexanonas/uso terapéutico , Humanos , Modelos Lineales , Nitrobenzoatos/uso terapéutico , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Espectrometría de Masas en Tándem/métodosRESUMEN
A Mn(II) complex, [Mn(dpeo)2](2+) (dpeo=1,2-di(pyridin-2-yl)ethanone oxime), activates O2, with ensuing stepwise oxidation of the methylene group in the ligands providing an alkoxide and ultimately a ketone group. X-ray crystal-structure analysis of an intermediate homoleptic alkoxide Mn(III) complex shows tridentate binding of the ligand via the two pyridyl groups and the newly installed alkoxide moiety, with the oxime group no longer coordinated. The structure of a Mn(II) complex of the final ketone ligand, cis-[MnBr2(hidpe)2] (hidpe=2-(hydroxyimino)-1,2-di(pyridine-2-yl)ethanone) shows that bidentate oxime/pyridine coordination has been resumed. H2(18)O and (18)O2 labeling experiments suggest that the inserted Oâ atoms originate from two different O2 molecules. The progress of the oxygenation was monitored through changes in the resonance-enhanced Raman bands of the oxime unit.
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Regime shifts triggered by human activities and environmental changes have led to significant ecological and socioeconomic consequences in marine and terrestrial ecosystems worldwide. Ecological processes and feedbacks associated with regime shifts have received considerable attention, but human individual and collective behavior is rarely treated as an integrated component of such shifts. Here, we used generalized modeling to develop a coupled social-ecological model that integrated rich social and ecological data to investigate the role of social dynamics in the 1980s Baltic Sea cod boom and collapse. We showed that psychological, economic, and regulatory aspects of fisher decision making, in addition to ecological interactions, contributed both to the temporary persistence of the cod boom and to its subsequent collapse. These features of the social-ecological system also would have limited the effectiveness of stronger fishery regulations. Our results provide quantitative, empirical evidence that incorporating social dynamics into models of natural resources is critical for understanding how resources can be managed sustainably. We also show that generalized modeling, which is well-suited to collaborative model development and does not require detailed specification of causal relationships between system variables, can help tackle the complexities involved in creating and analyzing social-ecological models.
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Ecología , Modelos Teóricos , Países Bálticos , Conservación de los Recursos Naturales , Investigación Empírica , Explotaciones Pesqueras , Océanos y MaresRESUMEN
Three new conglomerates incorporating bidentate sulfide ligands coordinated by Ru(II) centers have been prepared. Total spontaneous resolution by slow crystallization gives highly enantioenriched crystal batches, which are used in enantioselective oxidation of the sulfide ligands to give chiral sulfoxide complexes with >98 %â ee. All relevant stereoisomers have been characterized by single-crystal X-ray diffraction, CD spectroscopy, and chiral HPLC. If the ligand range can be extended to monodentate sulfides, a large-scale and recyclable process for enantioselective oxidation of sulfides can be designed.
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A Cr(iv)η(2)-peroxo complex crystallizes from 33% aqueous H2O2. The complex is a likely intermediate in catalytic disproportionation of H2O2 proposed to occur through a single metal site mechanism in solution - and solid state.