Shifts in soil and plant functional diversity along an altitudinal gradient in the French Alps.

OBJECTIVES: Altitude integrates changes in environmental conditions that determine shifts in vegetation, including temperature, precipitation, solar radiation and edaphogenetic processes. In turn, vegetation alters soil biophysical properties through litter input, root growth, microbial and macrofaunal interactions. The belowground traits of plant communities modify soil processes in different ways, but it is not known how root traits influence soil biota at the community level. We collected data to investigate how elevation affects belowground community traits and soil microbial and faunal communities. This dataset comprises data from a temperate climate in France and a twin study was performed in a tropical zone in Mexico. DATA DESCRIPTION: The paper describes soil physical and chemical properties, climatic variables, plant community composition and species abundance, plant community traits, soil microbial functional diversity and macrofaunal abundance and diversity. Data are provided for six elevations (1400-2400 m) ranging from montane forest to alpine prairie. We focused on soil biophysical properties beneath three dominant plant species that structure local vegetation. These data are useful for understanding how shifts in vegetation communities affect belowground processes, such as water infiltration, soil aggregation and carbon storage. Data will also help researchers understand how plant communities adjust to a changing climate/environment.

Scavenger receptor-B1 and luteal function in mice.

During luteinization, circulating high-density lipoproteins supply cholesterol to ovarian cells via the scavenger receptor-B1 (SCARB1). In the mouse, SCARB1 is expressed in cytoplasm and periphery of theca, granulosa, and cumulus cells of developing follicles and increases dramatically during formation of corpora lutea. Blockade of ovulation in mice with meloxicam, a prostaglandin synthase-2 inhibitor, resulted in follicles with oocytes entrapped in unexpanded cumulus complexes and with granulosa cells with luteinized morphology and expressing SCARB1 characteristic of luteinization. Mice bearing null mutation of the Scarb1 gene (SCARB1(-/-)) had ovaries with small corpora lutea, large follicles with hypertrophied theca cells, and follicular cysts with blood-filled cavities. Plasma progesterone concentrations were decreased 50% in mice with Scarb1 gene disruption. When SCARB1(-/-) mice were treated with a combination of mevinolin [an inhibitor of 3-hydroxy-3-methylglutaryl CoA reductase (HMGR)] and chloroquine (an inhibitor of lysosomal processing of low-density lipoproteins), serum progesterone was further reduced. HMGR protein expression increased in SCARB1(-/-) mice, independent of treatment. It was concluded that theca, granulosa, and cumulus cells express SCARB1 during follicle development, but maximum expression depends on luteinization. Knockout of SCARB1(-/-) leads to ovarian pathology and suboptimal luteal steroidogenesis. Therefore, SCARB1 expression is essential for maintaining normal ovarian cholesterol homeostasis and luteal steroid synthesis.

Mejora de la efectividad en el manejo del riesgo cardiovascular de pacientes diabéticos tipo 2 en atención primaria / Improved effectiveness in the management of cardiovascular risk among type 2 diabetic patients in primary health care

Objetivos: Determinar el impacto de la implementación de una guía en la valoración del riesgo cardiovascular de pacientes en alto riesgo (diabéticos tipo 2), y en la adecuación del tratamiento antihipertensivo y antiagregante.Diseño: Estudio semiexperimental, no aleatorizado, prospectivo, con grupo control concurrente.EmplazamientoDos centros de salud de Málaga.Participantes: Médicos de familia.Intervenciones: Implementación de la guía mediante intervenciones multicomponentes sobre los médicos de familia del centro experimental.Mediciones principales: Variable principal de resultado: grado de estimación del riesgo cardiovascular en población con elevado riesgo (diabéticos). Variables secundarias: adecuación del tratamiento antihipertensivo y antiagregante.Resultados: Se detectaron importantes diferencias en la estimación del riesgo cardiovascular a favor del grupo experimental (el 74,36 frente al 7,63%; riesgo relativo [RR]=9,74; intervalo de confianza [IC] del 95%, 5,15–18,43; p=0,0001). Las pautas de antiagregación se ajustaron más a las recomendaciones de la evidencia en el grupo intervención (el 51,28 frente al 36,44%; RR=1,407; IC del 95%, 1,04–1,89; p=0,026), al igual que en antihipertensivos, aunque sin significación (el 80 frente al 66,27%; RR=1,207; IC del 95%, 0,99–1,46.Conclusiones: Una estrategia de implementación multicomponente de una guía para el manejo de pacientes con elevado riesgo cardiovascular mejora la adherencia a intervenciones efectivas por parte de médicos de familia(AU)

Objectives: To determine the impact of the implementation of a guidelines in theassessment of cardiovascular risk in high-risk patients (type2diabetes) in health centres, and to analyse the appropriateness of antihypertensive and antiplatelet treatment in diabetic patients.Design: Quasi-experimental, non-randomised, prospective study with concurrent control group.Placement: Two health centres in Málaga.Participants: General practitioners of the two centres.Interventions: The guideline was implemented through a multifaceted intervention in family physicians in the experimental centre.Main outcomes: Rate of cardiovascular risk assessment in high risk population. Secondary: appropriateness of antihypertensive and antiplatelet treatment.Results: Large differences were detected in the cardiovascular risk assessment, improving in the experimental group (74.36% vs. 7.63%; RR ¼ 9.74; 95%CI, 5.15–18.43; P ¼.0001). Similarly, the antiplatelet use was more in line with the guidelines recommendations in theintervention group (51.28% vs. 36.44%; RR ¼ 1.407; 95%CI, 1.04–1.89; P ¼.026), andin antihypertensive drugs, although with no statistical significance (80% vs. 66.27%;RR ¼ 1.207; 95%CI, 0.99–1.46).Conclusions: A multifaceted intervention for the implementation of a guideline for the management of high risk cardiovascular patients, improves the adherence to effectiveinterventions by family physicians(AU)

[Improved effectiveness in the management of cardiovascular risk among type 2 diabetic patients in primary health care]. / Mejora de la efectividad en el manejo del riesgo cardiovascular de pacientes diabéticos tipo 2 en atención primaria.

OBJECTIVES: To determine the impact of the implementation of a guidelines in the assessment of cardiovascular risk in high-risk patients (type 2 diabetes) in health centres, and to analyse the appropriateness of antihypertensive and antiplatelet treatment in diabetic patients. DESIGN: Quasi-experimental, non-randomised, prospective study with concurrent control group. PLACEMENT: Two health centres in Málaga. PARTICIPANTS: General practitioners of the two centres. INTERVENTIONS: The guideline was implemented through a multifaceted intervention in family physicians in the experimental centre. MAIN OUTCOMES: Rate of cardiovascular risk assessment in high risk population. Secondary: appropriateness of antihypertensive and antiplatelet treatment. RESULTS: Large differences were detected in the cardiovascular risk assessment, improving in the experimental group (74.36% vs. 7.63%; RR = 9.74; 95% CI, 5.15-18.43; P = .0001). Similarly, the antiplatelet use was more in line with the guidelines recommendations in the intervention group (51.28% vs. 36.44%; RR = 1.407; 95% CI, 1.04-1.89; P = .026), and in antihypertensive drugs, although with no statistical significance (80% vs. 66.27%; RR = 1.207; 95% CI, 0.99-1.46). CONCLUSIONS: A multifaceted intervention for the implementation of a guideline for the management of high risk cardiovascular patients, improves the adherence to effective interventions by family physicians.

Lipoprotein receptor expression during luteinization of the ovarian follicle.

Ovarian follicles luteinize after ovulation, requiring structural and molecular remodeling along with exponential increases in steroidogenesis. Cholesterol substrates for luteal steroidogenesis are imported via scavenger receptor-BI (SR-BI) and the low-density lipoprotein (LDL) receptor from circulating high-density lipoproteins and LDL. SR-BI mRNA is expressed in pig ovaries at all stages of folliculogenesis and in the corpus luteum (CL). An 82-kDa form of SR-BI predominates throughout, is weakly present in granulosa cells, and is robustly expressed in the CL, along with the less abundant 57-kDa form. Digestion of N-linked carbohydrates substantially reduced the SR-BI mass in luteal cells, indicating that differences between forms is attributable to glycosylation. Immunohistochemistry revealed SR-BI to be concentrated in the cytoplasm of follicular granulosa cells, although found mostly at the periphery of luteal cells. To examine receptor dynamics during gonadotropin-induced luteinization, pigs were treated with an ovulatory stimulus, and ovaries were collected at intervals to ovulation. SR-BI in granulosa cell cytoplasm increased through the periovulatory period, with migration to the cell periphery as the CL matured. In vitro culture of follicles with human chorionic gonadotropin induced time-dependent upregulation of 82-kDa SR-BI in granulosa cells. SR-BI and LDL receptor were reciprocally expressed, with the latter highest in follicular granulosa cells, declining precipitously with CL formation. We conclude that luteinization causes upregulation of SR-BI expression, its posttranslational maturation by glycosylation, and insertion into luteal cell membranes. Expression of the LDL receptor is extinguished during luteinization, indicating dynamic regulation of cholesterol importation to maintain elevated steroid output by the CL.

Evaluación de especies forrajeras en América tropical: avances o status Quo / Forage species evaluation in tropical America: advancement or status Quo

La producción extensiva de ganado en pastoreo afecta marcadamente los ecosistemas tropicales y áridos; además de ser antigua y de gran arraigo, su persistencia es segura en un futuro mediato como consecuencia del comportamiento del mercado, por lo que tiene cabida el mejoramiento de las áreas bajo pastoreo. Los recursos forrajeros en México y Latinoamérica adolecen de un esquema de utilización adecuado. Para la mayoría de los productores, las gramíneas para pastoreo surgen como una moda cuando hay necesidad de mejorar el agostadero o pastizal, sin conocimiento de los atributos de la especie de interés, su origen o estirpe, y sin una caracterización adecuada. Ello ha generado dependencia en la importación de variedades y especies, así como gastos de recursos económicos y humanos. En este ensayo se discute la importancia de revalorar la utilización adecuada de recursos genéticos de las especies forrajeras de mayor impacto en la región y, junto a una tecnología de pastoreo adecuada, alcanzar alternativas viables a corto plazo y de bajo costo para impulsar la industria ganadera de producción en pastoreo, respetando al ecosistema y promoviendo su mejor condición. Avances tales como aprovisionamiento de recursos genéticos, tipos reproductivos y su manejo, y selección por marcadores moleculares, entre otros, ofrecen expectativas para incrementar la productividad y conservar áreas naturales no perturbadas en zonas de pastoreo. El desafío es reflexionar acerca de las metodologías actuales de investigación en forrajes y lograr avances en las especies relevantes, con aprovechamiento adecuado de recursos y mayor impacto de especies silvestres con estructura genómica intacta.

Between-year changes in functional gender expression of Palicourea padifolia (Rubiaceae), a distylous, hummingbird-pollinated shrub.

BACKGROUND AND AIMS: Because distylous species have two hermaphroditic style-length floral morphs, they face two sex allocation problems: the equilibrium morph ratio and the optimal allocation to pollen and seed production in each floral morph. Gender specialization is expected among distylous species when floral morphs differ in reproductive output. However, spatio-temporal variability in female reproductive output between morphs needs to be investigated to fully understand patterns of sexual expression and gender specialization in distylous plants. Between-year variation in flower and fruit production of hummingbird-pollinated Palicourea padifolia (Rubiaceae) was examined, focusing on functional gender expression of long- and short-styled morphs and comparing their reproductive performance in five consecutive years (1998-2002). METHODS: Between-year variation in inflorescence, floral bud and fruit production was monitored and quantified. These traits were then used as parameters to determine functional gender differences between floral morphs through time. KEY RESULTS: Inflorescence production varied among years but no significant differences were found between floral morphs. Long-styled plants initiated more floral buds per inflorescence every year than short-styled plants, suggesting higher allocation to pollinator attraction and, potentially, an increase in male fitness through pollen donation. Although fruit production was similar between morphs, their functional gender shifted across years. CONCLUSIONS: The gender expression inconsistency across years is surprising because a number of floral characters and attributes that contribute to differently attracting and rewarding effective pollinators in P. padifolia suggest gender specialization. The evidence that morphs of distylous species might specialize in functional gender mostly comes from differences among populations in seed production and non-equilibrium morph ratios based on 1-year field population surveys. The results suggest that more sampling through time is needed to detect gender specialization among distylous species with a perennial habit.

Reproductive ecology of distylous Palicourea Padifolia (Rubiaceae) in a tropical montane cloud forest. I. Hummingbirds' effectiveness as pollen vectors.

The adaptiveness of distyly has been typically investigated in terms of its female function, specifically pollen receipt. However, pollen loads on stigmas can only provide moderate support for Darwin's hypothesis of the promotion of legitimate crosses. To determine the effectiveness of hummingbirds as pollen vectors between floral morphs and the consequences in terms of male (pollen transfer) and female function (pollen receipt) in Palicourea padifolia (Rubiaceae), floral visitors, their foraging modes, and temporal patterns of floral visitation were observed and documented. Differences in pollen and stigma morphology, pollen flow, rates of pollen deposition, and/or stigmatic pollen loads were then evaluated for their contribution toward differences in reproductive output between floral morphs. A pollination experiment with stuffed hummingbirds that varied in bill size was done to evaluate the contribution of bill variation toward differences between floral morphs in pollen receipt and pollen transfer and female reproductive output. Anthers of long-styled flowers contained significantly more and smaller pollen grains than those of short-styled flowers, independently of corolla and anther lengths. The shape and orientation of the stigma lobes differed between morphs and were significantly longer among short-styled flowers. Hummingbird visitation rates did not differ significantly between floral morphs, and foraging movements from focal plants towards neighboring plants were independent of floral morph. Stigmatic pollen loads under field conditions and those after controlled hummingbird visitation, along with rates of pollen accumulation through the day indicated that stigmas of short-styled flowers receive proportionately more legitimate (intermorph) pollen grains than did those of long-styled flowers. However, the species of hummingbird was marginally significant in explaining variation in pollen deposition on stigmas. Lastly, intermorph pollinations of P. padifolia resulted in significant differences in fruit production between floral morphs, independent of pollination treatment and pollinator species; short-styled flowers proportionately developed almost twice the number of fruits developed by long-styled flowers.

Reproductive ecology of distylous Palicourea padifolia (Rubiaceae) in a tropical montane cloud forest. II. Attracting and rewarding mutualistic and antagonistic visitors.

By definition, the floral morphs of distylous plants differ in floral architecture. Yet, because cross-pollination is necessary for reproductive success in both morphs, they should not differ in attributes that contribute to attracting and rewarding floral visitors. Floral and vegetative attributes that function in distylous polymorphism in hummingbird-pollinated Palicourea padifolia (Rubiaceae) and the responses of pollinators and insect herbivores to the resources offered by both morphs were investigated. The performance of each morph along multiple stages of the reproductive cycle, from inflorescence and nectar production to fruit production, was surveyed, and pollinator behavior and nectar standing crops were then observed. Costs associated with such attractiveness were also evaluated in terms of herbivore attack and of plant reproductive fitness (female function) as a function of leaf herbivory. The number of inflorescences, floral buds, open flowers, and ripe fruits offered by either floral morph were similar, but short-styled plants almost doubled the number of developing fruits of long-styled plants. Long-styled flowers produced higher nectar volumes and accumulated more nectar over time than short-styled flowers. Measures of nectar standing crop and data on pollinator behavior suggest that hummingbirds respond to this morph-specific scheduling of nectar production. Lastly, long-styled plants suffered a higher herbivore attack and lost more leaf area over time than those with short-styled flowers. Herbivory was negatively correlated with fruit number and fruit mass, and long-styled plants set significantly less fruit mass than short-styled plants. The results suggest that pollinators and herbivores may exert selective pressures on floral and vegetative traits that could also influence gender function.