Biological nitrogen fixation (BNF) supports terrestrial primary productivity and plays key roles in mediating human-induced changes in global nitrogen (N) and carbon cycling. However, there are still ...critical uncertainties in our understanding of the amount of BNF occurring across terrestrial ecosystems, and of how terrestrial BNF will respond to global change. We synthesized BNF data from Latin America, a region reported to sustain some of the highest BNF rates on Earth, but that is underrepresented in previous data syntheses. We used meta-analysis and modeling approaches to estimate BNF rates across Latin America's major biomes and to evaluate the potential effects of increased N deposition and land-use change on these rates. Unmanaged tropical and subtropical moist forests sustained observed and predicted total BNF rates of 10 ± 1 and 14 ± 1 kg N ha−1 y−1, respectively, supporting the hypothesis that these forests sustain lower BNF rates than previously thought. Free-living BNF accounted for two-thirds of the total BNF in these forests. Despite an average 30% reduction of free-living BNF in response to experimental N-addition, our results suggest free-living BNF rate responses to current and projected N deposition across tropical and subtropical moist forests are small. In contrast, the conversion of unmanaged ecosystems to crop and pasture lands increased BNF rates across all terrestrial biomes, mostly in savannas, grasslands, and dry forests, increasing BNF rates 2-fold. The information obtained here provides a more comprehensive understanding of BNF patterns for Latin America.
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•How much biological nitrogen fixation (BNF) occurs in the biosphere is uncertain.•Latin America (LA) sustains high BNF but is underrepresented in previous syntheses.•We estimated BNF across LA using meta-analysis and modeling approaches.•Tropical moist forests in LA sustain lower BNF than previously thought.•The conversion of unmanaged to agriculture lands increased BNF up to 2-fold in LA.
Introduction The closure of forensic psychiatric hospitals and the conversion to a residential model of care based on secure residential units in the community (REMS) has made Italy the first and ...only country in the world to have followed the principles of the deinstitutionalization movement. Following the reform, several management issues have emerged, such as the creation of long waiting lists for admission to REMS. Improper hospitalization in Acute Psychiatric Units (SPDC) has often been used to address this issue. In addition, the handover of inmates’ care to Mental Health Departments (DSMD’s) has posed further challenges. To date, the field has received little attention from international literature. Objectives Description and analysis of a sample of offender inpatients hospitalized in an acute psychiatric unit. Methods We conducted a retrospective study including male offenders admitted to the SPDC of San Gerardo Hospital (ASST Monza), between January 2007 and September 2022. Data analysis was performed by using SPSS. Results 120 male offenders were included for a total of 204 admissions. 98 offenders (81.7%) were hospitalized once. We observed an absolute (N=1; N=30) and percentage (0.2%;12%) increase in the number of hospitalized offenders per year during the time period under study. Jail was the main provenance in the sample (46.6%), followed by residential care facilities (27%) and the psychiatric observation unit (ROP) of Monza’s jail (10.8%). The two most prevalent diagnoses were personality disorders (37.5%) and psychosis (39.2%). In addition, 66 subjects (55%) had a history of substance abuse. The average duration of hospitalization was 19.45 days; it increased to 77 days for inpatients waiting to be transferred to REMS. Hetero-aggressive behavior as the reason for admission was associated with longer hospitalization (p=0.031), while attempted suicide correlated to shorter hospital stay (p=0.032). Out of the 55 offenders who attempted suicide, 41 came from jail (74.5%). Finally, longer hospitalizations were associated with an increased number of adverse events (p=0.001). Conclusions Psychiatric hospitalizations of offenders have increased over the last years. This population tends to require longer hospital stays (regional average of SPDC hospitalization in Lombardy: 14 days), which are even lengthier for inpatients destined to REMS. Longer hospitalizations exert a large burden on DSMD’s and impact the general health of patients, exposing them to a higher risk of adverse events. Further studies are needed to confirm our findings and to develop better strategies for the management and care of offender patients. Disclosure of Interest None Declared
Claustral foundation of nests by Atta sexdens Forel (Hymenoptera: Formicidae) involves great effort by its queens, solely responsible for the cultivation of the fungus and care for her offspring at ...this stage. The minimum workers, after 4 months, open access to the external environment to foraging plants to cultivate the symbiotic fungus, which decomposes the plant fragments and produces gongilidea nodules as food for the individuals in the colony. Colony gas exchange and decomposition of organic matter in underground ant nests generate carbon dioxide (CO
) emitted into the atmosphere. We described the carbon dioxide concentration in colonies in the field. The objective was to evaluate the carbon dioxide concentration in initial A. sexdens colonies, in the field, and their development. The CO
level was also measured in 4-month-old colonies in the field, using an open respirometric system fitted with an atmospheric air inlet. The CO
level of the respirometric container was read by introducing a tube into the nest inlet hole and the air sucked by a peristaltic pump into the CO
meter box. The CO
concentration in the initial colony was also measured after 4 months of age, when the offspring production (number of eggs, larvae, pupae and adult workers) stabilized. Ten perforations (15 cm deep) was carried out in the adjacent soil, without a nest of ants nearby, to determine the concentration of CO
. The composition of the nests in the field was evaluated after excavating them using a gardening shovel and they were stored in 250 ml pots with 1 cm of moistened plaster at the bottom. The CO
concentration was higher in field nest than in adjacent soil. The concentration of carbon dioxide in A. sexdens nests in the field is higher than in those in the soil, due to the production of CO
by the fungus garden and colony.
Queens of Atta sexdens Forel (Hymenoptera: Formicidae) face biotic and abiotic environmental factors in the environment while establishing their nests. Biotic factors such as predation, microbial ...pathogens, successful symbiotic fungus regurgitation, excavation effort and abiotic factors such as radiant sunlight, temperature, density, and soil moisture exert selection pressures on ant queens. Biotic factors such as temperature and solar irradiation affect the survival of the initial colony differently, in different environments in the field. Queens of the leaf-cutting ant A. sexdens, were installed in sunny and shaded conditions to test this hypothesis. Two hundred A. sexdens queens were collected and individualized in two experimental areas (sunny and shaded), each in an experimental area (25 m
) in the center of a square (50 × 50 cm). Temperature, irradiance, nest depth, rainfall and queen mortality were evaluated. Atta sexdens colony development was better in the shaded environment, and the depth and volume of the initial chamber, fungus garden biomass and number of eggs, larvae, pupae and workers were greater. The queen masses were similar in both environments but mortality was higher in the sunny environment. The worse parameter values for A. sexdens nests in the sunny environment are due to the greater solar irradiance, increasing the variation range of the internal temperature of the initial chamber of the nest. On the other hand, the more stable internal temperature of this chamber in the shaded environment, is due to the lower incidence of solar irradiance, which is also more advantageous for queen survival and the formation and development of A. sexdens colonies. Shaded environments are a better micro habitat for nesting A. sexdens than sunny ones.
Nest ventilation should be particularly relevant for the huge colonies of leaf-cutting ants, genus Atta. Considerable amounts of O2 are consumed and CO2 produced by both the fungus gardens and the ...ants inside nest chambers, which are located at deep soil layers characterized by high CO2 and low O2 concentrations. In this work, passive nest ventilation was investigated in field Atta capiguara and Atta laevigata nests, first, by evaluating air movements through the nest using propane as tracer gas as well as the CO2 and O2 concentrations of the circulating air, and second, by exposing the internal nest morphology with the use of cement casts and excavations. Results showed that even though outflow of CO2-rich air and inflow of O2-rich air occurred at high-placed and low-placed openings, respectively, supporting a wind-induced interpretation of air movements through the nest, circulating air was never detected inside fungus chambers. The CO2 and O2 levels inside the fungus chambers increased and decreased with increasing soil depth, respectively, and were in the range observed in the soil phase. Based on the underground nest architecture, it is concluded that although the external shape of the nest induces underground air circulation, the inflowing air is unable to directly reach the fungus chambers. It is argued that colony respiration completely depends on diffusive flows between the chamber air and the adjacent nest and soil atmospheres. Circulating air, although not directly renewing the air inside the nest chambers, may contribute to colony respiration by increasing the capacity of the nest and soil airs to act as an O2-source and a CO2-sink, because of the decrease in the CO2 and the increase in the O2 levels in the underground air phase. Possible adaptations of both ants and fungus to the high CO2 and low O2 concentrations usually found in soils are discussed.
The techniques LC-UV-BPSU and LC-UV-SPE/NMR were applied for the first time in the analysis of açai berry (
Mart.) pulp extracts. Those techniques allowed the identification of twenty-three ...metabolites: Valine (1), citric acid (2), tachioside (3), isotachioside (4),
-guaiacylglycerol (5), syringylglycerol (6), uridine (7), adenosine (8), dimethoxy-1,4-benzoquinone (9), koaburaside (10), protocatechuic acid (11), eurycorymboside B (12), 7',8'-dihydroxy-dihydrodehydroconiferyl alcohol-9-
-
-glucopyranoside (13), orientin (14), homoorientin (15), dihydrokaempferol-3-glucoside (16), isolariciresinol-9'-
-glucopyranoside (17), 5'-methoxyisolariciresinol-9'-
-glucopyranoside (18), cyanidin-3-
-glucoside (19), cyandin-3-
-rutenoside (20), 9,12-octadecadienoic acid (Z,Z)-2-hydroxy-1-(hydroxymethyl) ethyl ester (21), linolenic acid (22), and 1,2-di-
-
-linolenoyl-3-
-galactopyranosyl-sn-glycerol (23). In this plant, compounds 3, 4, 5, 6, 8, 10, 12, 17, 18, 21, and 23 are reported for the first time. All the structures were determined through extensive analyses of 1D and 2D NMR data, mass spectrometry, and comparison with published data. This methodology has proven to be an efficient alternative to the analysis of complex extracts containing a large variety of compounds.
This paper describes the use of the electrostatic layer-by-layer (LbL) technique for the preparation of bioanodes with potential application in ethanol/O2 biofuel cells. More specifically, the LbL ...technique was employed for immobilization of dehydrogenase enzymes and polyamidoamine (PAMAM) dendrimers onto carbon paper support. Both mono (anchoring only the enzyme alcohol dehydrogenase, ADH) and bi-enzymatic (anchoring both ADH and aldehyde dehydrogenase, AldDH) systems were tested. The amount of ADH deposited onto the Toray® paper was 95ngcm−2 per bilayer. Kinetic studies revealed that the LbL technique enables better control of enzyme disposition on the bioanode, as compared with the results obtained with the bioanodes prepared by the passive adsorption technique. The power density values achieved for the mono-enzymatic system as a function of the enzyme load ranged from 0.02 to 0.063mWcm−2 for the bioanode containing 36 ADH bilayers. The bioanodes containing a gas diffusion layer (GDL) displayed enhanced performance, but their mechanical stability must be improved. The bi-enzymatic system generated a power density of 0.12mWcm−2. In conclusion, the LbL technique is a very attractive approach for enzyme immobilization onto carbon platform, since it enables strict control of enzyme disposition on the bioanode surface with very low enzyme consumption.
Sagittal abdominal diameter (SAD) has been proposed as a surrogate marker of insulin resistance (IR). However, the utilization of SAD requires specific validation for each ethnicity. We aimed to ...investigate the potential use of SAD, compared with classical anthropometrical parameters, as a surrogate marker of IR and to establish the cutoff values of SAD for screening for IR.
A multicenter population survey on metabolic disorders was conducted. A race-admixtured sample of 824 adult women was assessed. The anthropometric parameters included: BMI, waist circumference (WC), waist-to-hip ratio and SAD. IR was determined by a hyperglycemic clamp and the HOMA-IR index.
After adjustments for age and total body fat mass, SAD (r = 0.23 and r = -0.70) and BMI (r = 0.20 and r = -0.71) were strongly correlated with the IR measured by the HOMA-IR index and the clamp, respectively (p < 0.001). In the ROC analysis, the optimal cutoff for SAD in women was 21.0 cm. The women with an increased SAD presented 3.2 (CI 95%: 2.1-5.0) more likelihood of having IR, assessed by the HOMA-IR index compared with those with normal SAD (p < 0.001); whereas women with elevated BMI and WC were 2.1 (95% CI: 1.4-3.3) and 2.8 (95% CI: 1.7-4.5) more likely to have IR (p < 0.001), respectively. No statistically significant results were found for waist-to-hip ratio.
SAD can be a suitable surrogate marker of IR. Understanding and applying routine and simplified methods is essential because IR is associated with an increased risk of obesity-related diseases even in the presence of normal weight, slight overweight, as well as in obesity. Further prospective analysis will need to verify SAD as a determinant of clinical outcomes, such as type 2 diabetes and cardiovascular events, in the Brazilian population.
Fungus-growing ants of the genus Atta are known for their leaf-cutting habit, a lifestyle they have maintained since their 50-million-year-old co-evolution with a mutualistic fungus, cultivated as ...food. Recent studies have highlighted that, in addition to the mutualistic fungus, nests of ants harbor a great diversity of microbial communities. Such microorganisms include the dematiaceous fungi, which are characterized by their melanized cell walls. In order to contribute to the knowledge of fungal ecology, as well as opportunistic strains that may be dispersed by these social insects, we isolated and identified fungi carried by gynes of Atta capiguara and Atta laevigata, collected from colonies located in Fazenda Santana, Botucatu (São Paulo, Brazil). The isolation was carried out using the oil flotation technique, which is suitable for the growth of black fungi. Inoculated plates were incubated at 25 and 35 °C until black cultures were visible (20–45 days). Isolates were identified based on microscopic and molecular characteristics. Some isolated genera were: Cladophialophora, Cladosporium, Exophiala, Ochroconis, Phaeococcomyces, Phialophora and Penidiella. Hyaline species were also found. The results obtained from this work showed that leaf-cutting gynes may contribute to the dispersal of opportunistic dematiaceous fungi. It is suggested that more attention should be paid to this still unexplored subject.
This paper describes the preparation and application of a novel bioanode for use in ethanol/O
2 biofuel cells based upon immobilization of alcohol dehydrogenase (ADH) and polyamidoamine (PAMAM) ...dendrimers onto carbon cloth platforms. The power density measurements indicated a direct relationship between the amount of anchored ADH and the anode power values, which increased upon enzyme loading. The power density values ranged from 0.04 to 0.28
mW
cm
−2, and the highest power density was achieved with the bioanode prepared with 28
U of ADH, which provided a power density of 0.28
mW
cm
−2 at 0.3
V. The latter power output values were the maximum observed, even for higher enzyme concentrations. Stability of the bioanodes was quite satisfactory, since there was no appreciable reduction of enzymatic activity during the measurements. The method of bioanode preparation described here has proven to be very effective. The PAMAM dendrimer represents a friendly environment for the immobilization of enzymes, and it is stable and capable of generating high power density compared to other immobilization methods.
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