LA NOCIÓN DE BIODIVERSIDAD EN LOS ECOSISTEMAS PASCÍCOLAS ESPAÑOLES

La noción de biodiversidad entre los ecólogos, aunque se remonta al menos a la primera mitad del siglo XX, adquiere carta de naturaleza en 1986 en el Foro Nacional sobre Biodiversidad de Washington. A partir de este momento, a esta variable estrictamente biológica o ecológica se le dan valores de calidad ambiental, culturales, ecológicos, estéticos e incluso espirituales. Por otro lado, en el estudio de los ecosistemas pascícolas, a día de hoy, ya no sólo se tienen en cuenta los aspectos relativos a la producción agroganadera en sentido estricto sino otros objetivos tales como la conservación del paisaje y la protección de la diversidad vegetal y animal, ligada ésta última no sólo a las especies silvestres sino también a la genética de las razas ganaderas autóctonas. Con relación a los pastos españoles, existe gran cantidad de información sobre biodiversidad, producida especialmente en el ámbito de la SEEP, y que, aunque dispersa en el tiempo, permite elaborar todo un cuerpo de doctrina al respecto. En este artículo se trata de sintetizar y sistematizar dicha información. Aunque el eje del artículo se refiere a los pastos españoles, se ha pretendido también, de forma implícita, desarrollar una teoría sobre diversidad comúnmente aceptada en la actualidad. Tras unas cuestiones generales sobre el concepto de biodiversidad, se aborda el caso concreto de los pastos españoles comenzando por el espectro de biodiversidad a nivel espacial: diversidad específica (índices y métodos de medida, superficie de muestreo, valores del índice de Shannon, condiciones ecológicas, peso diferencial de las especies, balance de la biodiversidad, megadiversidad), otros niveles taxonómicos de diversidad (nivel genético, táxones supraespecíficos, microorganismos), diversidad espacial, diversidad geográfica y diversidad y fitosociología. Se dedica igualmente un epígrafe especial al caso de los pastos con arbolado. El modelo temporal de la biodiversidad se desarrolla en un capítulo sobre la sucesión vegetal y se hace especial referencia a la intervención del pastoreo en los procesos sucesionales, a la sucesión post-abandono de cultivos y a la sucesión post-fuego. La intervención antrópica sobre la diversidad se articula en epígrafes dedicados al pastoreo (pastoreo selectivo, pisoteo del ganado, excretas y fertilización, endozoocoria, exozoocoria, intensidad del pastoreo, diversificación ganadera y vías pecuarias como corredores ecológicos), al desbroce del monte (mecánico y con fuego) y al caso de los pastos naturales más antropizados, los prados de siega (geomorfología del terreno, abonado y producción, calidad de la hierba y momento de siega). Finaliza el artículo con un epígrafe dedicado a los espacios naturales protegidos y a la importancia que tiene conservar en ellos la explotación ganadera con el fin de mantener la biodiversidad. Se concluye la necesidad de considerar, en adelante, la conservación de la biodiversidad en los pastos, como uno de los paradigmas de la Pascicultura del siglo XXI

Effect of fenugreek (Trigonella foenum-graecum L.) intake on glycemia: A meta-analysis of clinical trials

10.1186/1475-2891-13-7Nutrition Journal131

Association of melanocortin 1 receptor gene (MC1R) polymorphisms with skin reflectance and freckles in Japanese.

Most studies on the genetic basis of human skin pigmentation have focused on people of European ancestry and only a few studies have focused on Asian populations. We investigated the association of skin reflectance and freckling with genetic variants of melanocortin 1 receptor (MC1R) gene in Japanese. DNA samples were obtained from a total of 653 Japanese individuals (ages 19-40 years) residing in Okinawa; skin reflectance was measured using a spectrophotometer and freckling status was determined for each individual. Lightness index (L*) and freckling status were not correlated with age, body mass index or ancestry (Ryukyuan or Main Islanders of Japan). Among the 10 nonsynonymous variants that were identified by direct sequencing of the coding region of MC1R, two variants--R163Q and V92M--with the derived allele frequencies of 78.6 and 5.5%, respectively, were most common. Multiple regression analysis showed that the 163Q allele and the presence of nonsynonymous rare variants (allele frequencies <5%) were significantly associated with an increase in sex-standardized skin lightness (L* of CIELAB (CIE 1976 (L*a*b*) color space)) of the inner upper arm. Relative to the 92V allele, the 92M allele was significantly associated with increased odds of freckling. This is the first study to show an association between the 163Q allele and skin reflectance values; this association indicated that light-toned skin may have been subjected to positive selection in East Asian people

Proteasomal degradation of the histone acetyl transferase p300 contributes to beta-cell injury in a diabetes environment

In type 2 diabetes, amyloid oligomers, chronic hyperglycemia, lipotoxicity, and pro-inflammatory cytokines are detrimental to beta-cells, causing apoptosis and impaired insulin secretion. The histone acetyl transferase p300, involved in remodeling of chromatin structure by epigenetic mechanisms, is a key ubiquitous activator of the transcriptional machinery. In this study, we report that loss of p300 acetyl transferase activity and expression leads to beta-cell apoptosis, and most importantly, that stress situations known to be associated with diabetes alter p300 levels and functional integrity. We found that proteasomal degradation is the mechanism subserving p300 loss in beta-cells exposed to hyperglycemia or pro-inflammatory cytokines. We also report that melatonin, a hormone produced in the pineal gland and known to play key roles in beta-cell health, preserves p300 levels altered by these toxic conditions. Collectively, these data imply an important role for p300 in the pathophysiology of diabetes

Meadows quality in Huesca Pyrenees: botanical and chemical assessment methods

Ponencia presentada a la 51 Reunión Científica de la SEEP celebrada en la Escuela Superior de Ingenieros Agrónomos de la Universidad Pública de Navarra entre el 14 y el 18 de mayo de 2012.Se ha realizado, durante junio y julio de 2008 y 2009, un control de 160 parcelas de prados del Pirineo aragonés. Se presentan datos de cobertura por familias (gramíneas, leguminosas y “otras”), de análisis de valoración botánica (métodos del Valor pastoral -VP- y del Complex), de análisis químico-bromatológicos (PB, Cenizas, FND, FAD y LAD) y, a partir de estos últimos, cálculos de parámetros de valor nutritivo (ingestión -IMS- y digestibilidad -DMS- de la materia seca y valor relativo del forraje -VRF-). Se concluye que los dos métodos de valoración botánica están altamente correlacionados entre sí, por lo que sería preferible optar por el VP por su mayor simplicidad. Sin embargo, se ha obtenido correlación negativa entre los resultados de calidad de los métodos botánicos y de los químicos, lo que se explica porque en estos últimos se analiza “toda” la hierba, incluyendo plantas tóxicas, plantas mecánicamente perjudiciales y plantas no apetecibles, que el ganado no consume o no debería consumir, casi todas del grupo de “otras”, que sí son despreciadas en los métodos botánicos. Estos últimos, por tanto, deberían primar sobre los químicos en comunidades de pastos polifitos y con alta biodiversidad vegetal, máxime si se consumen en pastoreo.Field sampling consisting of 160 stands was done in June and July of 2008 and 2009 in Aragonese Pyrenean meadows. Family coverage (grasses, legumes and forbs), value assessment by means of two botanical methods (Pastoral Value -PV- and Complex methods) and chemical analyses (CP, Ashes, NDF, ADF and ADL) are showed. From the chemical analyses, quality parameters (dry matter intake and digestibility, and relative forage value) were calculated. As the two botanical assessment methods were highly correlated, it was concluded that PV methods should be preferred, due to its highest simplicity. Nevertheless, a negative correlation was found between the results of botanical and chemical assessments. In the chemical assessment, the whole grass sample is analyzed, including toxic, mechanically damaging and non-palatable species. Almost all of these species are included in the ‘forbs’ group, are not (or should not be) eaten by the livestock, and are discarded when applying the botanical methods. We conclude that botanical methods should be chosen versus chemical methods when applied to multi-species, highly diverse communities, remarkably in grazed pastures.Este trabajo se enmarca en el Proyecto PM076/2007 del Gobierno de Aragón

Deciphering neuronal deficit and protein profile changes in human brain organoids from patients with creatine transporter deficiency

Creatine transporter deficiency (CTD) is an X-linked disease caused by mutations in the SLC6A8 gene. The impaired creatine uptake in the brain results in intellectual disability, behavioral disorders, language delay, and seizures. In this work, we generated human brain organoids from induced pluripotent stem cells of healthy subjects and CTD patients. Brain organoids from CTD donors had reduced creatine uptake compared with those from healthy donors. The expression of neural progenitor cell markers SOX2 and PAX6 was reduced in CTD-derived organoids, while GSK3β, a key regulator of neurogenesis, was up-regulated. Shotgun proteomics combined with integrative bioinformatic and statistical analysis identified changes in the abundance of proteins associated with intellectual disability, epilepsy, and autism. Re-establishment of the expression of a functional SLC6A8 in CTD-derived organoids restored creatine uptake and normalized the expression of SOX2, GSK3β, and other key proteins associated with clinical features of CTD patients. Our brain organoid model opens new avenues for further characterizing the CTD pathophysiology and supports the concept that reinstating creatine levels in patients with CTD could result in therapeutic efficacy

Acute interaction between hydrocortisone and insulin alters the plasma metabolome in humans

With the aim of identifying biomarkers of glucocorticoid action and their relationship with biomarkers of insulin action, metabolomic profiling was carried out in plasma samples from twenty healthy men who were administered either a low or medium dose insulin infusion (n = 10 each group). In addition, all subjects were given metyrapone (to inhibit adrenal cortisol secretion) +/-hydrocortisone (HC) in a randomised crossover design to produce low, medium and high glucocorticoid levels. The clearest effects of insulin were to reduce plasma levels of the branched chain amino acids (BCAs) leucine/isoleucine and their deaminated metabolites, and lowered free fatty acids and acylcarnitines. The highest dose of hydrocortisone increased plasma BCAs in both insulin groups but increased free fatty acids only in the high insulin group, however hydrocortisone did not affect the levels of acyl carnitines in either group. The clearest interaction between HC and insulin was that hydrocortisone produced an elevation in levels of BCAs and their metabolites which were lowered by insulin. The direct modulation of BCAs by glucocorticoids and insulin may provide the basis for improved in vivo monitoring of glucocorticoid and insulin action

The evolution of tooth wear indices

Tooth wear—attrition, erosion and abrasion—is perceived internationally as an ever-increasing problem. Clinical and epidemiological studies, however, are difficult to interpret and compare due to differences in terminology and the large number of indices that have been developed for diagnosing, grading and monitoring dental hard tissue loss. These indices have been designed to identify increasing severity and are usually numerical. Some record lesions on an aetiological basis (e.g. erosion indices), others record lesions irrespective of aetiology (tooth wear indices); none have universal acceptance, complicating the evaluation of the true increase in prevalence reported. This article considers the ideal requirements for an erosion index. It reviews the literature to consider how current indices have evolved and discusses if these indices meet the clinical and research needs of the dental profession