Sex ratio of Western Bluebirds Sialia mexicana is mediated by phenology and clutch size.

Mothers may produce more of one sex to maximize their fitness if there are differences in the cost of producing each sex or there are differences in their relative reproductive value. Breeding date and clutch size are known to influence offspring sex ratios in birds through sex differences in dispersal, social behaviours, differential mortality, and available food resources. We tested if breeding date, clutch size and drought conditions influenced offspring sex ratios in a sexually size-monomorphic species, the Western Bluebird, by interrogating a 21-year dataset. After controlling for differential mortality, we found that hatch dates late in the breeding season were associated with the production of more females, suggesting that the value of producing males declines as the breeding season progresses. When clutch size was taken into account, small clutches yielded significantly more females late in the breeding season compared to the early and middle parts of the breeding season that produced significantly more males. Large clutches early in the season tended to produce more females, although this was not significant. Drought severity was not correlated with sex ratio adjustment. We propose and discuss several explanations for these patterns, including male offspring, but not female offspring, acting as helpers, increased female nestling provisioning late in the breeding season, differences in food abundance, and egg-laying order. Future work will help to uncover the mechanisms leading to these patterns. Identifying patterns and mechanisms of sex ratio skew from long-term datasets is important for informing predictions regarding life-history trade-offs in wildlife populations.

A novel functional low-density lipoprotein receptor-related protein 6 gene alternative splice variant is associated with Alzheimer's disease.

We previously found that single nucleotide polymorphisms in the low-density lipoprotein receptor-related protein 6 (LRP6) gene are associated with Alzheimer's disease (AD). Here, we studied the posttranscriptional metabolism of the LRP6 message scanning sequentially the 23 LRP6 exons in human tissues and found a novel LRP6 isoform that completely skips exon 3 (LRP6Δ3) in all tissues examined and was also conserved in mice. Expression levels of the LRP6 isoforms were determined in 47 cortical brain messenger (m)RNA samples including 22 AD cases, 11 control subjects, and 14 individuals with other neurological disorders. LRP6Δ3 mRNA levels were significantly augmented in AD brains compared with controls (1.6-fold; p = 0.037) or other pathological samples (2-fold; p = 0.007). Functional analysis in Wnt/ß-catenin signaling assays revealed that skipping of exon 3 reduced significantly the signaling activity of the LRP6 coreceptor. We conclude that the LRP6Δ3 isoform is a novel splice variant, which shows diminished Wnt/ß-catenin signaling activity and might have a functional role in individuals with AD.

Canonical Wnt3a modulates intracellular calcium and enhances excitatory neurotransmission in hippocampal neurons.

A role for Wnt signal transduction in the development and maintenance of brain structures is widely acknowledged. Recent studies have suggested that Wnt signaling may be essential for synaptic plasticity and neurotransmission. However, the direct effect of a Wnt protein on synaptic transmission had not been demonstrated. Here we show that nanomolar concentrations of purified Wnt3a protein rapidly increase the frequency of miniature excitatory synaptic currents in embryonic rat hippocampal neurons through a mechanism involving a fast influx of calcium from the extracellular space, induction of post-translational modifications on the machinery involved in vesicle exocytosis in the presynaptic terminal leading to spontaneous Ca(2+) transients. Our results identify the Wnt3a protein and a member of its complex receptor at the membrane, the low density lipoprotein receptor-related protein 6 (LRP6) coreceptor, as key molecules in neurotransmission modulation and suggest cross-talk between canonical and Wnt/Ca(2+) signaling in central neurons.

Computer-assisted bar-coding system significantly reduces clinical laboratory specimen identification errors in a pediatric oncology hospital.

OBJECTIVE: To assess the ability of a bar code-based electronic positive patient and specimen identification (EPPID) system to reduce identification errors in a pediatric hospital's clinical laboratory. STUDY DESIGN: An EPPID system was implemented at a pediatric oncology hospital to reduce errors in patient and laboratory specimen identification. The EPPID system included bar-code identifiers and handheld personal digital assistants supporting real-time order verification. System efficacy was measured in 3 consecutive 12-month time frames, corresponding to periods before, during, and immediately after full EPPID implementation. RESULTS: A significant reduction in the median percentage of mislabeled specimens was observed in the 3-year study period. A decline from 0.03% to 0.005% (P < .001) was observed in the 12 months after full system implementation. On the basis of the pre-intervention detected error rate, it was estimated that EPPID prevented at least 62 mislabeling events during its first year of operation. CONCLUSIONS: EPPID decreased the rate of misidentification of clinical laboratory samples. The diminution of errors observed in this study provides support for the development of national guidelines for the use of bar coding for laboratory specimens, paralleling recent recommendations for medication administration.

Phylogenetic relationships of family groups in Pentatomoidea based on morphology and DNA sequences (Insecta: Heteroptera).

Phylogenetic relationships within the Pentatomoidea are investigated through the coding and analysis of character data derived from morphology and DNA sequences. In total, 135 terminal taxa were investigated, representing most of the major family groups; 84 ingroup taxa are coded for 57 characters in a morphological matrix. As many as 3500 bp of DNA data are adduced for each of 52 terminal taxa, including 44 ingroup taxa, comprising the 18S rRNA, 16S rRNA, 28S rRNA, and COI gene regions. Character data are analysed separately and in the form of a total evidence analysis. Major conclusions of the phylogenetic analysis include: the concept of Urostylididae is restricted to that of earlier authors; the Saileriolinae is raised to family rank and treated as the sister group of all Pentatomoidea exclusive of Urostylididae sensu stricto; a broadly conceived Cydnidae, as recognized by Dolling, 1981, is not supported; the placement of Thaumastellidae within the Pentatomoidea is affirmed and the taxon is recognized at family rank rather than as a subfamily of Cydnidae, although its exact phylogenetic position within the Pentatomoidea remains equivocal; the Parastrachiinae is treated as also including Dismegistus Amyot & Serville and placed within a broadly conceived Corimelaenidae, the latter group being treated at family rank; the family-group taxa Dinidoridae and Tessaratomidae probably represent a monophyletic group, but the recognition of monophyletic subgroups will benefit from additional representation in the sequence data set; and the Lestoniidae is treated as the sister group of the Acanthosomatidae. The Acanthosomatidae and Scutelleridae are consistently recovered as monophyletic. The monophyly of the Pentatomidae appears unequivocal, inclusive of the Aphylinae and Cyrtocorinae, on the basis of morphology, the latter two taxa not being represented in the molecular data set. © The Willi Hennig Society 2008.

Behavior and endocrine concentrations do not distinguish sex in monomorphic juvenile howlers (Alouatta palliata).

Behavioral observations on juvenile mantled howlers are limited by visually undifferentiated genitalia; however, animals can be sexed when they are very young or if they are captured. Behavioral data and fecal samples from juveniles during month-long field studies from 1993 to 1995 were analyzed to determine whether there are developmental differences in behavior or hormone concentrations that can be used to differentiate males from females. The subjects were juveniles of known sex and age from five different social groups on Hacienda La Pacifica, Costa Rica. Based on 749.8 hr of focal-animal sampling, there were no sex differences in daily activity patterns. There were no sex differences in proximity to mothers and other group members, and age differences reflected howler life-history patterns. There were no differences in estradiol or testosterone concentration by age or sex. Juvenile monomorphy thus extends beyond morphology to behavioral and hormonal similarity as well. Most juveniles are forced out of their natal groups and remain solitary until they join new groups by supplanting all same-sex adult group members. Monomorphy may allow them to spend more time in natal groups, and thus both reduce the solitary period and allow the juveniles to improve social skills needed for later immigration. While this strategy may benefit juvenile howlers, it remains a problem for those who wish to study juvenile sex differences from a distance.

Fibrinolisis intrarterial directa en el manejo terapéutico del accidente cerebrovascular agudo / Fibrinolysis in acute ischaemic stroke

El tratamiento de los pacientes con un accidente cerebrovascular agudo incluye, en casos seleccionados, el cateterismo y la infusión de agentes trombolíticos directamente en el coágulo de una arteria cerebral intracraneana. Se procede a la infusión de fibrinolíticos dentro del trombo hasta lograr la lisis y restablecer la perfusión. Esto se ha hecho en 27 pacientes incluyendo 45 territorios vasculares. Se logró mejoría clínica en 18 (66,7 por ciento) de los casos. Las complicaciones incluyeron 3 hemorragias intracraneanas sintomáticas (11,1 por ciento), un caso (3,7 por ciento) de perforación vascular, 8 (26,9 por ciento) pacientes sin mejoría y 9 (33,3 por ciento) muertes en el seguimiento alejado. La infusión local directa de trombolíticos puede mejorar la morbilidad global y la mortalidad relacionadas con enfermedad aguda tromboembólica en el sistema nervioso central

Fibrinolisis intrarterial directa en el manejo terapéutico del accidente cerebrovascular agudo / Fibrinolysis in acute ischaemic stroke

El tratamiento de los pacientes con un accidente cerebrovascular agudo incluye, en casos seleccionados, el cateterismo y la infusión de agentes trombolíticos directamente en el coágulo de una arteria cerebral intracraneana. Se procede a la infusión de fibrinolíticos dentro del trombo hasta lograr la lisis y restablecer la perfusión. Esto se ha hecho en 27 pacientes incluyendo 45 territorios vasculares. Se logró mejoría clínica en 18 (66,7 por ciento) de los casos. Las complicaciones incluyeron 3 hemorragias intracraneanas sintomáticas (11,1 por ciento), un caso (3,7 por ciento) de perforación vascular, 8 (26,9 por ciento) pacientes sin mejoría y 9 (33,3 por ciento) muertes en el seguimiento alejado. La infusión local directa de trombolíticos puede mejorar la morbilidad global y la mortalidad relacionadas con enfermedad aguda tromboembólica en el sistema nervioso central (AU)