Analysis of body condition indices reveals different ecotypes of the Antillean manatee.

Assessing the body condition of wild animals is necessary to monitor the health of the population and is critical to defining a framework for conservation actions. Body condition indices (BCIs) are a non-invasive and relatively simple means to assess the health of individual animals, useful for addressing a wide variety of ecological, behavioral, and management questions. The Antillean manatee (Trichechus manatus manatus) is an endangered subspecies of the West Indian manatee, facing a wide variety of threats from mostly human-related origins. Our objective was to define specific BCIs for the subspecies that, coupled with additional health, genetic and demographic information, can be valuable to guide management decisions. Biometric measurements of 380 wild Antillean manatees captured in seven different locations within their range of distribution were obtained. From this information, we developed three BCIs (BCI1 = UG/SL, BCI2 = W/SL3, BCI3 = W/(SL*UG2)). Linear models and two-way ANCOVA tests showed significant differences of the BCIs among sexes and locations. Although our three BCIs are suitable for Antillean manatees, BCI1 is more practical as it does not require information about weight, which can be a metric logistically difficult to collect under particular circumstances. BCI1 was significantly different among environments, revealing that the phenotypic plasticity of the subspecies have originated at least two ecotypes-coastal marine and riverine-of Antillean manatees.

Association mapping for maize stover yield and saccharification efficiency using a multiparent advanced generation intercross (MAGIC) population.

Cellulosic ethanol derived from fast growing C4 grasses could become an alternative to finite fossil fuels. With the potential to generate a major source of lignocellulosic biomass, maize has gained importance as an outstanding model plant for studying the complex cell wall network and also to optimize crop breeding strategies in bioenergy grasses. A genome-wide association study (GWAS) was conducted using a subset of 408 Recombinant Inbred Lines (RILs) from a Multi-Parent Advanced Generation Intercross (MAGIC) Population in order to identify single nucleotide polymorphisms (SNPs) associated with yield and saccharification efficiency of maize stover. We identified 13 SNPs significantly associated with increased stover yield that corresponded to 13 QTL, and 2 SNPs significantly associated with improved saccharification efficiency, that could be clustered into 2 QTL. We have pointed out the most interesting SNPs to be implemented in breeding programs based on results from analyses of averaged and yearly data. Association mapping in this MAGIC population highlight genomic regions directly linked to traits that influence the final use of maize. Markers linked to these QTL could be used in genomic or marker-assisted selection programs to improve biomass quality for ethanol production. This study opens a possible optimisation path for improving the viability of second-generation biofuels.

Exploring tomato Solanum pennellii introgression lines for residual biomass and enzymatic digestibility traits.

BACKGROUND: Residual biomass production for fuel conversion represents a unique opportunity to avoid concerns about compromising food supply by using dedicated feedstock crops. Developing tomato varieties suitable for both food consumption and fuel conversion requires the establishment of new selection methods. RESULTS: A tomato Solanum pennellii introgression population was assessed for fruit yield, biomass phenotypic diversity, and for saccharification potential. Introgression lines 2-5, 2-6, 6-3, 7-2, 10-2 and 12-4 showed the best combination of fruit and residual biomass production. Lignin, cellulose, hemicellulose content and saccharification rate showed a wide variation in the tested lines. Within hemicellulose, xylose value was high in IL 6-3, IL 7-2 and IL 6-2, whereas arabinose showed a low content in IL 10-2, IL 6-3 and IL 2-6. The latter line showed also the highest ethanol potential production. Alkali pre-treatment resulted in the highest values of saccharification in most of lines tested, suggesting that chemical pretreatment is an important factor for improving biomass processability. Interestingly, extreme genotypes for more than one single trait were found, allowing the identification of better genotypes. Cell wall related genes mapping in genomic regions involved into tomato biomass production and digestibility variation highlighted potential candidate genes. Molecular expression profile of few of them provided useful information about challenged pathways. CONCLUSIONS: The screening of S. pennellii introgression population resulted very useful for delving into complex traits such as biomass production and digestibility. The extreme genotypes identified could be fruitfully employed for both genetic studies and breeding.

Factors associated with depression and suicide attempts in patients undergoing rehabilitation for substance abuse.

BACKGROUND: Comorbidity of major depression with substance abuse increases the risk of committing suicide. The objective of this work was to determine the psychological and socio-demographic factors associated with depression and suicide attempts in patients rehabilitating for drug consumption. METHOD: 57 Patients attending a center for drug abuse treatment answered the following instruments: the Mini-international neuropsychiatric interview, a questionnaire of general information and background data on consumption of substances, depression and suicide attempts, and the Spanish adaptation of the Holmes and Rahe scale for the assessment of life events. Chi-square and logistic regression tests were used to establish associations between variables. RESULTS: 68.4% of the Patients had current major depression, of these, 75.4% experienced it before the onset of substance abuse. Patients attempting suicide before drug use corresponded to 26%, whilst 28.1% attempted suicide within the last year. Current depression-related variables were receiving a diagnosis of depression prior to the consumption of drugs and the first used drugs, which were alcohol or marijuana. The adverse life event "Familial drug abuse history", was also significantly related to depression (p=0.02). Variables associated with current suicide attempts were: receiving a diagnosis of depression prior to the consumption of drugs (p=0.02), and suicide attempts previous to drug use (p<0.003). LIMITATION: A limitation of this study was the small size of the sample. CONCLUSION: Patients with depression who attempted suicide prior to the use of drugs also experienced these conditions during the rehabilitation process. Substance use in the family was a risk factor for both, underscoring the need of actions aimed at preventing addictions in the household environment.

The role of trehalose-6-phosphate synthase in Arabidopsis embryo development.

We previously showed that trehalose-6-phosphate synthase 1 (TPS1), which catalyses the first step in trehalose synthesis, is essential for embryo maturation in Arabidopsis. The tps1 mutant embryos develop more slowly than wild type. Patterning in the tps1 embryos appears normal but they do not progress past the torpedo stage to cotyledon stage, which is when storage reserves start to accumulate in the expanding cotyledons. Our initial data led to the hypothesis that trehalose metabolism plays a key role in regulating storage reserve accumulation by allowing the embryo to respond to the dramatic increase in sucrose levels that occurs at the torpedo stage of embryo development. More recent data demonstrate that while the tps1 mutant is blocked in the developmental progression of embryos from torpedo to cotyledon stage the expression of genes involved in the accumulation of storage reserves proceeds in a similar fashion to wild type. Thus it appears that induction of metabolic processes required for accumulation of storage reserves in tps1 occurs independently of the developmental stage and instead follows a temporal programme similar to wild-type seeds in the same silique.

Regulation of calcium signalling and gene expression by glutathione.

The glutathione redox couple is an information-rich redox buffer that interacts with numerous cellular components. To explore the role of glutathione in redox signalling, leaf contents were increased either chemically, by feeding reduced glutathione (GSH), or genetically, by over-expressing the first enzyme of the GSH biosynthetic pathway, gamma-glutamylcysteine synthetase (gamma-ECS). Leaf discs were also fed glutathione disulphide (GSSG), leading to increases in both GSH and GSSG. The effects of increases in GSH were compared with non-specific changes in leaf thiol status induced by feeding dithiothreitol (DTT) or the monothiol beta-mercaptoethanol (beta-ME). Photosynthesis measurements showed that none of the feeding treatments greatly disrupted leaf physiology. Transgenic plants expressing aequorin were used to analyse calcium signatures during the feeding treatments. Calcium release occurred soon after the onset of GSH or GSSG feeding, but was unaffected by DTT or beta-ME. Pathogenesis-related protein 1 (PR-1) was induced both in the gamma-ECS overexpressors and by feeding GSH, but not GSSG. Feeding DTT also induced PR-1. Key transcripts encoding antioxidative enzymes were much less affected, although glutathione synthetase was suppressed by feeding thiols or GSSG. It is concluded that modulation of glutathione contents transmits information through diverse signalling mechanisms, including (i) the establishment of an appropriate redox potential for thiol/disulphide exchange and (ii) the release of calcium to the cytosol.

[Resupinate basidiomycetes from Costa Rica. New or rare species of Atractiellales (Auriculariales s.l.), Exidiaceae, Sirobasidiaceae y Tremellaceae]. / Basidiomicetos resupinados de Costa Rica. Especies nuevas o raras de Atractiellales (Auriculariales s.l.), Exidiaceae, Sirobasidiaceae y Tremellaceae.

Species of Atractiellales (Auriculariaceae s.l.), Exidaceae, Sirobasidaceae and Tremellaceae are reported as new for Costa Rica or as new to science, Tremella coalescens L.S. Olive, Sirobasidium minutum Kisim., Oberw. & Gómez sp. nov., Heterochaete vitrea Kisim., Oberw. & Gómez sp. nov., Exidiopsis mucedinea (Pat.) K. Wells, Helicogloea aurea Baker, Saccoblastia sphaerospora Möller and Occultifur internus (L.S. Olive) Oberw. All the new species are described and illustrated. Since the original material collected in Brazil by Möller is lost, a neotype for Saccoblastia sphaerospora Möller is proposed. This Costa Rican collection represents the first record since the discovery of the species in 1891. Hyphoderma argillaceum (Bres.) Donk is reported for the first time from Costa Rica as the fungal host of Occultifur internus.

[Resupinate basidiomycetes from Costa Rica. Myxariaceae s. Jülich, Sebacinaceae Wells & Oberw., and Tremellodendropsidaceae Jülich]. / Basidiomicetos resupinados de Costa Rica. Myxariaceae s. Jülich, Sebacinaceae Wells & Oberw., y Tremellodendropsidaceae Jülich.

Thirteen representatives of Myxariaceae sensu Jülich: Heterochaetella brachyspora (Bourdot & Galzin) Luck-Allen, Myxarium atratum (Peck) Ginns & Lefebvre, M. granulum Hauersl., M. laccatum (Bourdot & Galzin) Reid, M. mesomorphum (Bourdot & Galzin) Haursl., M. mesonucleatum Kisim., Oberw. & L.D. Gómez nov. sp., M. subsphaerosporum Kisim., Oberw. & L.D. Gómez nov. sp., Protodontia subgelatinosa (Karst.) Pilát; Pseudohydum gelatinosum (Fr.) P. Karst., P. gelatinosum var. paucidentata Lowy; one species of Sebacinaceae, Efibulobasidium albescens (Sacc. & Malbr.) K. Wells; and the Tremellodrendropisidaceae Tremellodendropsis flagelliformis (Berk.) Crawford var.ovalispora Crawford, are reported or described from Costa Rica. The corticioid Cystidiodontia artocreas (Berk & Curt. ex Cooke) Hjortstam is also reported from Costa Rica.

Inactivation and degradation of CuZn-SOD by active oxygen species in wheat chloroplasts exposed to photooxidative stress.

Changes in CuZn-SOD activity and content in isolated wheat chloroplasts under the light, and the involvement of protease(s) and/or active oxygen species in this process were studied. Both SOD activity and content decayed with exposure time to photooxidative stress. Ascorbate, a H2O2 scavenger, prevented photooxidation-associated inactivation of SOD, while benzoate, a .OH scavenger, prevented SOD degradation. Wheat chloroplasts incubated in the dark did not hydrolyze exogenous or endogenous SOD, either H2O2-pretreated or not. Protease inhibitors did not prevent SOD degradation under photooxidative treatment, suggesting that plastid protease(s) did not participate in this process. Purified chloroplast CuZn-SOD was exposed to H2O2 and O2- or .OH-generating systems. O2- had no effect on either SOD activity or stability (estimated by native PAGE). H2O2 up to 700 microM inhibited SOD in a dose-dependent manner and induced charge/mass changes as seen by native PAGE. .OH also reduced SOD activity by inducing its fragmentation. High levels of active oxygen, as can be generated under strong stress conditions, could directly inactivate and degrade chloroplastic SOD.

Diurnal variation in the somatic cell count of ewe milk.

The hourly variation of SCC in milk throughout the period between milkings was studied in 60 half udders of 30 Manchega ewes (10 each in first, second, and third parities) for 2 consecutive d. The interval between milkings was 12 h. The effects half udder, sampling time and day, interaction hour by day, and parity were statistically significant and explained 58.9, 11.9, 1.3, .6, and .3%, respectively, of total variance. The hourly repeatabilities of SCC and log SCC within each day (.83 and .86, respectively) were high. The SCC increased 70% in the 1st h postmilking and then gradually decreased until the next milking. The variations in SCC from 6 h postmilking were statistically significant but of less quantitative importance than those from the previous hours. The mean SCC of a.m. and p.m. milkings were very similar on both days (112 and 114 x 10(3) cells/ml). The mean SCC difference of milk between a.m. and p.m. milkings was 14%. This variation could be considered to be normal in the ewe for an interval of 12 h between milkings. These results suggest the standardization of time of sampling to avoid erroneous classifications of sheep based on SCC of milk.

A new Coelomomyces pathogenic to mosquitoes in Costa Rica.

A new species of fungus belonging to the lethal genus Coelomomyces, C. neotropicus, is described and illustrated. It was found parasitizing larvae of two species of Culicidae, Culex pilosus and Aedes sp., in a lowland tropical wet forest swamp in northeast Costa Rica.

[Obtaining of serum (antibodies) of antitrophozoites of Giardia lamblia and non-specific factors. A practical method]. / Obtención de sueros (anticuerpos) de antitrofozitos de Giardia lamblia y elementos inespecíficos. Un método práctico.

According to some authors, the nonspecific elements belong to Candida albicans morphologic variables, and according to others, they represent an evolutive stage or are the result of Giardia lamblia. An immunitary methodology is developed in experimental animals combining intramuscular, intravascular and intraperitoneal pathways with soluble substances and extracts which can be absorbed in aluminium hydroxide of Giardia lamblia and nonspecific elements trophocytes. Sera (antibodies) to these organisms are obtained.