内蒙古阿尔山地区落叶松八齿小蠹天敌及其控制作用

通过对内蒙古阿尔山地区落叶松八齿小蠹Ipssubelongatus Motschulsky天敌的种类调查,目前共发现落叶松八齿小蠹天敌包括捕食性天敌红胸郭公虫Thanasimus substriatus Gebler,寄生性天敌暗绿截尾金小蜂Tomicobia seitneri(Ruschka)、长蠹刻鞭茧蜂Coeloides bostrichorum Giraud以及螨类、微生物。分析了天敌的自然控制作用,红胸郭公虫对落叶松八齿小蠹成虫的日均捕食率为3.1%±0.77%(落叶松八齿小蠹成虫20头和红胸郭公虫成虫1头,室外12～24℃),日最大捕食量为10.7头(1头红胸郭公虫成虫与20、40、60和80头、100头落叶松八齿小蠹成虫,室内17～25℃);暗绿截尾金小蜂对落叶松八齿小蠹幼虫的寄生率为20.5%,对其蛹的寄生率为13.7%;长蠹刻鞭茧蜂对其幼虫的寄生率为6.5%;螨类对其成虫的寄生率为20.2%;而微生物对落叶松八齿小蠹幼虫的寄生率为4.3%,对蛹的寄生率为5.4%,对成虫的寄生率为2.1%。暗绿截尾金小蜂是落叶松八齿小蠹最有利用价值的天敌昆虫。     

Intermuscular force transmission between human plantarflexor muscles in vivo

The exact mechanical function of synergist muscles within a human limb in vivo is not well described. Recent studies indicate the existence of a mechanical interaction between muscle actuators that may have functional significance and further play a role for injury mechanisms. The purpose of the present study was to investigate if intermuscular force transmission occurs within and between human plantarflexor muscles in vivo. Seven subjects performed four types of either active contractile tasks or passive joint manipulations: passive knee extension, voluntary isometric plantarflexion, voluntary isometric hallux flexion, passive hallux extension, and selective percutaneous stimulation of the gastrocnemius medialis (MG). In each experiment plantar- and hallux flexion force and corresponding EMG activity were sampled. During all tasks ultrasonography was applied at proximal and distal sites to assess task-induced tissue displacement (which is assumed to represent loading) for the plantarflexor muscles [MG, soleus (SOL), and flexor hallucis longus (FHL)]. Selective MG stimulation and passive knee extension resulted in displacement of both the MG and SOL muscles. Minimal displacement of the triceps surae muscles was seen during passive hallux extension. Large interindividual differences with respect to deep plantarflexor activation during voluntary contractions were observed. The present results suggest that force may be transmitted between the triceps surae muscles in vivo, while only limited evidence was provided for the occurrence of force transfer between the triceps surae and the deeper-lying FHL.     

Species distribution models reveal apparent competitive and facilitative effects of a dominant species on the distribution of tundra plants

Abiotic factors are considered strong drivers of species distribution and assemblages. Yet these spatial patterns are also influenced by biotic interactions. Accounting for competitors or facilitators may improve both the fit and the predictive power of species distribution models (SDMs). We investigated the influence of a dominant species, Empetrum nigrum ssp. hermaphroditum, on the distribution of 34 subordinate species in the tundra of northern Norway. We related SDM parameters of those subordinate species to their functional traits and their co‐occurrence patterns with E. hermaphroditum across three spatial scales. By combining both approaches, we sought to understand whether these species may be limited by competitive interactions and/or benefit from habitat conditions created by the dominant species. The model fit and predictive power increased for most species when the frequency of occurrence of E. hermaphroditum was included in the SDMs as a predictor. The largest increase was found for species that 1) co‐occur most of the time with E. hermaphroditum, both at large (i.e. 750 m) and small spatial scale (i.e. 2 m) or co‐occur with E. hermaphroditum at large scale but not at small scale and 2) have particularly low or high leaf dry matter content (LDMC). Species that do not co‐occur with E. hermaphroditum at the smallest scale are generally palatable herbaceous species with low LDMC, thus showing a weak ability to tolerate resource depletion that is directly or indirectly induced by E. hermaphroditum. Species with high LDMC, showing a better aptitude to face resource depletion and grazing, are often found in the proximity of E. hermaphroditum. Our results are consistent with previous findings that both competition and facilitation structure plant distribution and assemblages in the Arctic tundra. The functional and co‐occurrence approaches used were complementary and provided a deeper understanding of the observed patterns by refinement of the pool of potential direct and indirect ecological effects of E. hermaphroditum on the distribution of subordinate species. Our correlative study would benefit being complemented by experimental approaches.     

Recent vegetation changes at the high‐latitude tree line ecotone are controlled by geomorphological disturbance,productivity and diversity

Aim We test how productivity, disturbance rate, plant functional composition and species richness gradients control changes in the composition of high‐latitude vegetation during recent climatic warming. Location Northern Fennoscandia, Europe. Methods We resampled tree line ecotone vegetation sites sampled 26 years earlier. To quantify compositional changes, we used generalized linear models to test relationships between compositional changes and environmental gradients. Results Compositional changes in species abundances are positively related to the normalized difference vegetation index (NDVI)‐based estimate of productivity gradient and to geomorphological disturbance. Competitive species in fertile sites show the greatest changes in abundance, opposed to negligible changes in infertile sites. Change in species richness is negatively related to initial richness, whereas geomorphological disturbance has positive effects on change in richness. Few lowland species have moved towards higher elevations. Main conclusions The sensitivity of vegetation to climate change depends on a complex interplay between productivity, physical and biotic disturbances, plant functional composition and richness. Our results suggest that vegetation on productive sites, such as herb‐rich deciduous forests at low altitudes, is more sensitive to climate warming than alpine tundra vegetation where grazing may have strong buffering effects. Geomorphological disturbance promotes vegetation change under climatic warming, whereas high diversity has a stabilizing effect.     

<Emphasis Type="Italic">POLG1</Emphasis> p.R722H mutation associated with multiple mtDNA deletions and a neurological phenotype

Background  

The c.2447G>A (p.R722H) mutation in the gene POLG1 of the catalytic subunit of human mitochondrial polymerase gamma has been previously found in a few occasions but its pathogenicity has remained uncertain. We set out to ascertain its contribution to neuromuscular disease.     

Gradients of strain and strain rate in the hollow muscular organs of soft-bodied animals

The cylindrical shape of soft-bodied invertebrates is well suited to functions in skeletal support and locomotion, but may result in a previously unrecognized cost—large non-uniformities in muscle strain and strain rate among the circular muscle fibres of the body wall. We investigated such gradients of strain and strain rate in the mantle of eight long-finned squid Doryteuthis pealeii and two oval squid Sepioteuthis lessoniana. Transmural gradients of circumferential strain were present during all jets (n = 312); i.e. for a given change in the circumference of the outer surface of the mantle, the inner surface experienced a greater proportional change. The magnitude of the difference increased with the amplitude of the mantle movement, with circular muscle fibres at the inner surface of the mantle experiencing a total range of strains up to 1.45 times greater than fibres at the outer surface during vigorous jets. Differences in strain rate between the circular fibres near the inner versus the outer surface of the mantle were also present in all jets, with the greatest differences occurring during vigorous jetting. The transmural gradients of circumferential strain and strain rate we describe probably apply not only to squids and other coleoid cephalopods, but also to diverse soft-bodied invertebrates with hollow cylindrical or conical bodies and muscular organs.     

Efficacy of osteopathic manipulation as an adjunctive treatment for hospitalized patients with pneumonia: a randomized controlled trial

Background

The Multicenter Osteopathic Pneumonia Study in the Elderly (MOPSE) is a registered, double-blinded, randomized, controlled trial designed to assess the efficacy of osteopathic manipulative treatment (OMT) as an adjunctive treatment in elderly patients with pneumonia.

Methods

406 subjects aged ≥ 50 years hospitalized with pneumonia at 7 community hospitals were randomized using concealed allocation to conventional care only (CCO), light-touch treatment (LT), or OMT groups. All subjects received conventional treatment for pneumonia. OMT and LT groups received group-specific protocols for 15 minutes, twice daily until discharge, cessation of antibiotics, respiratory failure, death, or withdrawal from the study. The primary outcomes were hospital length of stay (LOS), time to clinical stability, and a symptomatic and functional recovery score.

Results

Intention-to-treat (ITT) analysis (n = 387) found no significant differences between groups. Per-protocol (PP) analysis (n = 318) found a significant difference between groups (P = 0.01) in LOS. Multiple comparisons indicated a reduction in median LOS (95% confidence interval) for the OMT group (3.5 [3.2-4.0] days) versus the CCO group (4.5 [3.9-4.9] days), but not versus the LT group (3.9 [3.5-4.8] days). Secondary outcomes of duration of intravenous antibiotics and treatment endpoint were also significantly different between groups (P = 0.05 and 0.006, respectively). Duration of intravenous antibiotics and death or respiratory failure were lower for the OMT group versus the CCO group, but not versus the LT group.

Conclusions

ITT analysis found no differences between groups. PP analysis found significant reductions in LOS, duration of intravenous antibiotics, and respiratory failure or death when OMT was compared to CCO. Given the prevalence of pneumonia, adjunctive OMT merits further study.     

Admixture Mapping of Obesity‐related Traits in African Americans: The Atherosclerosis Risk in Communities (ARIC) Study

Obesity is an important cause of morbidity and mortality worldwide. In the United States, the prevalence of obesity is higher in African Americans than whites, even after adjustment for socioeconomic status (SES). This leads to the hypothesis that differences in genetic background may contribute to racial/ethnic differences in obesity‐related traits. We tested this hypothesis by conducting a genome‐wide admixture mapping scan using 1,350 ancestry‐informative single‐nucleotide polymorphisms (SNPs) in 3,531 self‐identified blacks from the Atherosclerosis Risk in Communities (ARIC) study. We used these markers to estimate the overall proportions of European ancestry (PEAs) for each individual and then scanned for the association between PEA and obesity‐related traits (both continuous and dichotomous) at each locus. The median (interquartile range) PEA was 0.151 (0.115). PEA was inversely correlated with continuous BMI, weight, and subscapular skinfold thickness, even after adjusting for socioeconomic factors. In contrast, PEA was positively correlated with BMI‐adjusted waist circumference. Using admixture mapping on dichotomized traits, we identified a locus on 2p23.3 to be suggestively associated with BMI (locus‐specific lod = 4.11) and weight (locus‐specific lod = 4.07). After adjusting for global PEA, each additional copy of a European ancestral allele at the 2p23.3 peak was associated with a BMI decrease of ～0.92 kg/m² (P = 2.9 × 10^?5). Further mapping in this region on chromosome 2 may be able to uncover causative variants underlying obesity, which may offer insights into the control of energy homeostasis.     

Regulation of CCR5 Expression in Human Placenta: Insights from a Study of Mother-to-Child Transmission of HIV in Malawi

Background

Human promoter polymorphisms in the chemokine co-receptor 5 gene (CCR5) have been noted for association with mother-to-child transmission of HIV (HIV MTCT) as well as reduced receptor expression in vitro, but have not been clearly associated with CCR5 expression in vivo. Placental expression of CCR5 may be influenced by such polymorphisms as well as other in vivo regulatory factors.

Methodology/Principal Findings

We evaluated the associations between infant CCR5 polymorphisms, measures of maternal infection, and placental expression of CCR5 among mother-infant pairs in Blantyre, Malawi. RNA was extracted from placental tissue and used in multiplex real-time PCR to quantify gene expression. Through linear regression, we observed that CCR5-2554T (β = −0.67, 95% CI = −1.23, −0.11) and -2132T (β = −0.75, 95% CI = −0.131, −0.18) were significantly associated with reduced placental expression of CCR5. An incremental increase in CCR5 expression was observed for incremental increases in expression of two heparan sulfate genes involved in viral infection, HS3ST3A1 (β = 0.27, 95% CI = 0.18, 0.35) and HS3ST3B1 (β = 0.11, 95% CI = 0.06, 0.18). Among HIV infected mothers, an incremental increase in maternal HIV viral load was also associated with higher CCR5 expression (β = 0.76, 95% CI = 0.12, 1.39). Maternal HIV status had no overall effect (β = 0.072, 95% CI = −0.57, −0.72). Higher CCR5 expression was observed for mothers with malaria but was not statistically significant (β = 0.37, 95% CI = −0.43, 1.18).

Conclusions/Significance

These results provide in vivo evidence for genetic and environmental factors involved in the regulation of CCR5 expression in the placenta. Our findings also suggest that the measurement of placental expression of CCR5 alone is not an adequate indicator of the risk of mother-to-child transmission of HIV.