Functional diversity of snakes is explained by the landscape composition at multiple areas of influence.

Roadkill and landscape composition affect snakes at different spatial scales, depending on the functional trait value of the species, which is reflected in the functional diversity indices at the assemblage level. This study evaluated the effect of roads and landscape composition on snakes' functional diversity at different areas of influence (250, 500, 1000, and 2000 m buffer areas). We compared roadkill snake species with those assemblages inhabiting the adjacent vegetation in the Orinoco region, Colombia. We surveyed snakes using transects on the road and adjacent areas on 13 landscapes along the road. We evaluated the effect of 16 landscape metrics at six land cover classes on the snake's functional diversity at four different areas of influence (from 250 to 2000 m around the sampled sites). The functional redundancy index was higher for roadkill species, suggesting that roads eliminate species that play similar roles in the assemblage and ecosystem processes. Likewise, the low values of functional redundancy in the adjacent vegetation call attention to the fact that each species surviving in this transformed landscape has a crucial active role in ecosystem processes in snake assemblages. For roadkill snakes, forest metrics explained changes in functional richness and functional evenness at a 250 m area of influence. In comparison, transient crop and pasture metrics explained changes in functional evenness and divergence at 2000 m. For snakes inhabiting the adjacent vegetation, the cohesion of pasture explained changes in functional richness at 250 m, and forest metrics explained changes in functional redundancy and evenness at 2000 m. Anthropogenic landscape transformation may have a greater effect on snake functional diversity at local scales than roadkill. In savanna ecosystems, the presence of native forest at 2000 m radius around roads promotes the conservation of snake assemblages. However, within a 250 m radius, the risk of snake roadkill increases when the road borders native forest. Therefore, it is necessary to implement wildlife crossing in these sections of the road.

El atropellamiento en carreteras y la composición del paisaje afectan a las serpientes a diferentes escalas espaciales, dependiendo del valor del rasgo funcional de las especies, que se refleja en los índices de diversidad funcional a nivel de ensamblaje. Este estudio evaluó el efecto de las carreteras y la composición del paisaje en la diversidad funcional de las serpientes en diferentes áreas de influencia (250, 500, 1000 y 2000 m áreas de amortiguamiento). Comparamos las especies de serpientes atropelladas con los ensamblajes que habitan la vegetación adyacente en la región del Orinoco, Colombia. Muestreamos serpientes usando transectos en la carretera y áreas adyacentes en 13 paisajes a lo largo de una carretera. Evaluamos el efecto de 16 métricas de paisaje en seis clases de cobertura del suelo sobre la diversidad funcional de la serpiente en cuatro áreas diferentes de influencia (de 250 a 2000 m alrededor de los sitios muestreados). El índice de redundancia funcional fue mayor para las especies atropelladas, lo que sugiere que las carreteras eliminan especies que desempeñan funciones similares en los procesos de ensamblaje y ecosistema. Del mismo modo, los bajos valores de redundancia funcional en la vegetación adyacente llaman la atención sobre el hecho de que cada especie que sobrevive en este paisaje transformado tiene un papel crucial en los procesos ecosistémicos y dentro de los ensamblajes de serpientes. Para las serpientes atropelladas, las métricas de cobertura de bosque explicaron los cambios en la riqueza y la uniformidad funcional en un área de influencia de 250 m. En comparación, las métricas de cultivos transitorios y pastos explicaron los cambios en la uniformidad y divergencia funcional a 2000 m. Para las serpientes que habitan la vegetación adyacente, la cohesión de los pastizales explicó los cambios en la riqueza funcional a 250 m, y las métricas de cobertura de bosque explicaron los cambios en la redundancia y la uniformidad funcional a 2000 m. La transformación antropogénica del paisaje puede tener un mayor efecto en la diversidad funcional de las serpientes a escalas locales que los atropellos. En ecosistemas de sabana, la presencia de bosque nativo en un radio de 2000 m alrededor de las carreteras favorece la conservación de los ensamblajes de serpientes. Sin embargo, en un radio de 250 m se aumenta el riesgo de atropellamiento de serpientes cuando la carretera limita con bosque nativo, por lo que es necesario implementar pasos de fauna en estos tramos.

Plant-Community Vulnerability in Highly Fragmented Landscapes Is Higher in Secondary Forests Than in Old Growth Forests in the Andean-Amazonian Transition.

Increasing biodiversity in highly diverse plant communities can jointly increase ecosystem function and ecosystem vulnerability. This paradox requires further attention. This study analyzed the functional response of plant communities to above- and below-ground parameters along the chronosequence (degraded pastures (DP), early forests (EF), intermediate forests (IF), and old-growth forests (OF)) in two highly fragmented landscapes of the Colombian Amazon as an estimate of the level of functional vulnerability. Three sets of functional attributes were evaluated: (i) functional composition based on the community-weighted mean (CWM) of five traits; (ii) functional diversity based on the multi-trait indices and functional dispersion (FDis) of each individual trait; and (iii) the functional vulnerability at the community-level and species-level. The individual traits did not show a clear pattern along the chronosequence. However, the trend indicated an increase in the values of resource conservation traits with the age of abandonment. The functional response of the community did not vary between landscapes. Between DP and OF, there was a significant increase in functional diversity and a decrease in functional redundancy, which increased community-level vulnerability. Consequently, the more vulnerable species were observed in the IF and OF plots. In addition, a decrease in environmental parameters, such as penetration resistance, bulk density and Ca content, and an increase in slope, precipitation, electric conductivity, pH, clay, organic material, and P and N contents increased the vulnerability. We elucidated the need for secondary forest management in terms of conservation and restoration to maintain the capacity to respond to changing environmental conditions in highly fragmented landscapes in the Andean-Amazonian transition.

Nurse Practitioner Students' Perceptions on Delivering Culturally Congruent Care to Vulnerable Mexican Immigrants: A Qualitative Study.

Increasingly, nurse practitioners serve as vanguards in providing primary health care to vulnerable Mexican immigrants. The aims of this study were to explore the lived experiences of nurse practitioner students in caring for Mexican immigrant patients and to capture their meaning of cultural influences deemed essential to the delivery of culturally congruent care. An exploratory descriptive design was employed. Purposive sampling was used to select 17 nurse practitioner students who volunteered to complete a semistructured face-to-face audio-taped interview and follow-up focus group discussion. Constant comparison was utilized to analyze data. From this process, four distinct themes emerged: Culturally congruent care extends beyond race and ethnicity, understands the importance of therapeutic communication, accepts complementary and alternative medical modalities, and recognizes the importance of eating patterns, food choices, and perceptions of ideal weight and health. These findings build on our understanding of key evidence-based cultural beliefs and practices that are important in delivering culturally congruent care to this subgroup.

Transition-Metal-Free Multiple Functionalization of Piperidines to 4-Substituted and 3,4-Disubstituted 2-Piperidinones.

Remote and multiple functionalization of piperidines without the use of transition-metal catalysts and elaborate directing groups is one of the major challenges in organic synthesis. Herein is reported an unprecedented two-step protocol that enables the multiple functionalization of piperidines to either 4-substituted or trans-3,4-disubstituted 2-piperidones. First, by exploiting the duality of TEMPO reactivity, which under oxidative and thermal conditions fluctuates between cationic and persistent-radical form, a novel multiple C(sp3 )-H oxidation of piperidines to α,ß-unsaturated 2-piperidones was developed. Second, the intrinsic low reactivity of the unsaturated piperidones toward conjugated Grignard additions was overcome by using trimethylsilyl chloride (TMSCl) as Lewis acid. Subsequently, conjugated Grignard addition/electrophilic trapping protocol provided substituted 2-piperidone intermediates, some of which were then transformed into pharmaceutical alkaloids.

Bridging the Gaps Through Nurse-Led Nutrition Education to Underserved Children.

Although children residing in impoverished rural communities located along the Texas-Mexico border are at disproportionately high risk of unhealthy eating, limited resources may prevent devoting sufficient attention to school-based nutrition education. The purpose of this quasi-experimental study was to examine the teaching effectiveness of graduate nursing students on fourth-grade student learning about healthy eating. Purposive sampling was used to select 213 predominately Hispanic fourth-grade students enrolled in one of three low-socioeconomic status underserved elementary schools located in rural South Texas. Ten graduate nursing students implemented the Creating Healthy Eating Choices for Kids Nutrition Curriculum to approximately 40 fourth-graders per group who attended weekly 45- to 50-minute sessions for 6 weeks. The MyPlate standardized tests were administered before and following the intervention. Results showed a significant improvement in learning on all program modules for fourth-graders from each school ( p = .000). Results support the value of creating a strategic partnership between a university school of nursing and key community leaders as a feasible method of providing nutrition education for fourth-graders enrolled in schools with limited resources.

Asymmetric pyrone Diels-Alder reactions enabled by dienamine catalysis.

Despite the proven value in utilizing pyrone dienes to create molecular complexity via Diels-Alder reactions with varied dienophiles, few examples of effective catalytic, asymmetric variants of this process have been developed. Herein, we show that the use of Jørgensen-Hayashi-type catalysts can convert an array of α,ß-unsaturated aldehydes into chiral dienamines that can formally add in a Diels-Alder fashion to a number of electron-deficient pyrones of the coumalate-type to generate optically active [2.2.2]-bicyclic lactones. In most cases, the reactions proceed with good to excellent diastereo- and enantiocontrol (up to 99% ee). Models to explain that stereoselectivity, as well as several additional transformations of the resultant products, are also presented.

Synthesis of the Enantiomers of Tedanalactam and the First Total Synthesis and Configurational Assignment of (+)-Piplaroxide.

Highlighting the recently established methodology for the direct synthesis of glycidic amides from tertiary allyl amines, the synthesis of the enantiomers of tedanalactam were completed in two steps from the corresponding chiral dihydropiperidine. Additionally, the (+)- and (-)-enantiomers of piplaroxide were obtained from their respective tedanalactam precursor, and the absolute configuration of the naturally occurring (+)-piplaroxide was determined. The present approach represents not only the shortest synthesis of (-)-tedanalactam but also the first total synthesis of (+)-piplaroxide, a repellent against the leafcutter ant Atta cephalotes.

Effects of Increased Nitrogen Availability on C and N Cycles in Tropical Forests: A Meta-Analysis.

Atmospheric N deposition is predicted to increase four times over its current status in tropical forests by 2030. Our ability to understand the effects of N enrichment on C and N cycles is being challenged by the large heterogeneity of the tropical forest biome. The specific response will depend on the forest's nutrient status; however, few studies of N addition appear to incorporate the nutrient status in tropical forests, possibly due to difficulties in explaining how this status is maintained. We used a meta-analysis to explore the consequences of the N enrichment on C and N cycles in tropical montane and lowland forests. We tracked changes in aboveground and belowground plant C and N and in mineral soil in response to N addition. We found an increasing trend of plant biomass in montane forests, but not in lowland forests, as well as a greater increase in NO emission in montane forest compared with lowland forest. The N2O and NO emission increase in both forest; however, the N2O increase in lowland forest was significantly even at first time N addition. The NO emission increase showed be greater at first term compared with long term N addition. Moreover, the increase in total soil N, ammonium, microbial N, and dissolved N concentration under N enrichment indicates a rich N status of lowland forests. The available evidence of N addition experiments shows that the lowland forest is richer in N than montane forests. Finally, the greater increase in N leaching and N gas emission highlights the importance of study the N deposition effect on the global climate change.

Effects of precipitation regime and soil nitrogen on leaf traits in seasonally dry tropical forests of the Yucatan Peninsula, Mexico.

Leaf traits are closely associated with nutrient use by plants and can be utilized as a proxy for nutrient cycling processes. However, open questions remain, in particular regarding the variability of leaf traits within and across seasonally dry tropical forests. To address this, we considered six leaf traits (specific area, thickness, dry matter content, N content, P content and natural abundance (15)N) of four co-occurring tree species (two that are not associated with N2-fixing bacteria and two that are associated with N2-fixing bacteria) and net N mineralization rates and inorganic N concentrations along a precipitation gradient (537-1036 mm per year) in the Yucatan Peninsula, Mexico. Specifically we sought to test the hypothesis that leaf traits of dominant plant species shift along a precipitation gradient, but are affected by soil N cycling. Although variation among different species within each site explains some leaf trait variation, there is also a high level of variability across sites, suggesting that factors other than precipitation regime more strongly influence leaf traits. Principal component analyses indicated that across sites and tree species, covariation in leaf traits is an indicator of soil N availability. Patterns of natural abundance (15)N in foliage and foliage minus soil suggest that variation in precipitation regime drives a shift in plant N acquisition and the openness of the N cycle. Overall, our study shows that both plant species and site are important determinants of leaf traits, and that the leaf trait spectrum is correlated with soil N cycling.

The Stabilizing Role of the Intramolecular C-H···O Hydrogen Bond in Cyclic Amides Derived From α-Methylbenzylamine.

A series of five-, six-, seven-, and eight-membered lactams containing the chiral auxiliary α-methylbenzylamine were structurally analyzed and further studied by DFT calculations with the purpose to examine with detail the previously detected intramolecular C-H···O hydrogen-bonding interaction formed between the hydrogen atom of the α-methylbenzylamine and the carbonyl group of the cyclic amide. The main objective was to establish whether its presence does have a tangible relevance in their spatial arrangement in solution and in the solid state or is a simple and not stabilizing interaction.

Increasing body mass index, blood pressure, and Acanthosis Nigricans abnormalities in school-age children.

This retrospective quantitative study examined the relationships among gender, Acanthosis Nigricans (AN), body mass index (BMI), and blood pressure (BP) in children attending school Grades 1-9 in Southwest Texas. Of the 34,897 health screening records obtained for the secondary analysis, 32,788 were included for the study. A logistic regression analysis was carried out with AN as the dependent variable, with year, gender, BMI, and BP as independent variables. The results indicate that the rate of children in each grade with three positive markers increased 2% during a 3-year period between 2008 and 2010. In the 5-year period between 2005 and 2010, a clear trend of significantly higher numbers of children with both AN and BMI markers was apparent. Gender played a significant role as females were more likely to have the AN marker than males. Further study is indicated based on the increasing trend of school-age children in Texas with positive markers for AN, increased BMI and BP.

Direct chemical method for preparing 2,3-epoxyamides using sodium chlorite.

A direct method for preparing 2,3-epoxyamides from tertiary allylamines via a tandem C-H oxidation/double bond epoxidation using sodium chlorite is reported. Apparently, the reaction course consists of two steps: (i) allylic oxidation of the starting allylamine to corresponding unsaturated allylamide with sodium chlorite followed by (ii) epoxidation of the allylamide to the 2,3-epoxyamide mediated by hypochlorite ion, which is formed in situ by reduction of sodium chlorite. The reaction conditions tolerate the presence of free hydroxyl groups and typical functional groups such as TBS, aryl, alkyl, allyl, acetyl, and benzyl groups; however, when an activated aromatic ring (e.g., sesamol) is present in the substrate, the use of a scavenger is necessary.