Herbivore‐Free Time? Damage to New Leaves of Woody Plants after Hurricane Andrew1

All broadleaf woody plants of pinelands and hammocks (upland areas) in the northern parts of Everglades National Park were defoliated by the strong winds of Hurricane Andrew in August 1992. Most plants re‐leafed within two months of the storm, at which time we tagged newly produced leaves of eight species (five species in two hardwood hammocks and four in two pineland sites; one species was studied in both habitats), and monitored individual leaf area lost or damaged monthly for three months. We marked a second cohort of new leaves on the same individuals four months later and monitored these for three months. Herbivory rates in leaves of the first cohort were lower than observed in pre‐hurricane studies on two of the species, and lower in the first cohort than in the second cohort in six of the eight species studied, indicating that most insect herbivores were virtually absent for the first few months after the storm. Additionally, most species produced significantly larger leaves in the first cohort than the second cohort, and leaves of the second cohort were not significantly different in size from pre‐hurricane leaves in one species for which pre‐hurricane data were available. The large disturbance of the hurricane defoliated and reduced the above‐ground biomass of the plants, but apparently also eliminated most herbivores and competition for light, facilitating the recovery of the plants.     

Contribution of the sympathetic nervous system on the burn-associated impairment of CCL3 production

Previously, we have reported that the susceptibility of burned patients to infectious complications is increased when the production of CC-chemokine ligand 3 (CCL3) is impaired. In this study, the role of the sympathetic nervous system on impaired CCL3 production and antibacterial resistance following burn injuries was investigated. Normal mice were resistant (65% survival) to cecal ligation and puncture (CLP)-induced sepsis, while the same CLP killed 90% of thermally injured mice (TI-mice). However, TI-mice resisted CLP-induced sepsis (60% survival) when they were previously treated with CCL3 or sympathectomized with 6-hydroxydopamine (6-OHDA). Augmentation of host resistance against CLP-induced sepsis by 6-OHDA was abrogated by anti-CCL3 mAb treatment. Norepinephrine (NE) production was increased in circulation of TI-mice, and treatment of TI-mice with 6-OHDA resulted in the inhibition of NE secretion. CCL3 production was impaired in cultures of T cells from TI-mice or normal T cells treated with NE, even when stimulated with anti-CD3 mAb. However, CCL3 was produced by mAb-stimulated T cells from TI-mice previously treated with 6-OHDA. These results indicated that by inhibiting CCL3 production the sympathetic nervous system contributes to the increased susceptibility of TI-mice to sepsis.     

Survival of bighorn sheep (Ovis canadensis) commingled with domestic sheep (Ovis aries) in the absence of Mycoplasma ovipneumoniae

To test the hypothesis that Mycoplasma ovipneumoniae is an important agent of the bighorn sheep (Ovis canadensis) pneumonia that has previously inevitably followed experimental commingling with domestic sheep (Ovis aries), we commingled M. ovipneumoniae-free domestic and bighorn sheep (n=4 each). One bighorn sheep died with acute pneumonia 90 days after commingling, but the other three remained healthy for >100 days. This unprecedented survival rate is significantly different (P=0.002) from that of previous bighorn-domestic sheep contact studies but similar to (P>0.05) bighorn sheep survival following commingling with other ungulates. The absence of epizootic respiratory disease in this experiment supports the hypothesized role of M. ovipneumoniae as a key pathogen of epizootic pneumonia in bighorn sheep commingled with domestic sheep.     

Synthetic osteogenic extracellular matrix formed by coated silicon dioxide nanosprings

Background

Angiogenesis is widely investigated in conjunction with cancer development, in particular because of the possibility of early stage detection and of new therapeutic strategies. However, such studies are negatively affected by the limitations of imaging techniques in the detection of microscopic blood vessels (diameter 3-5 ??m) grown under angiogenic stress. We report that synchrotron-based X-ray imaging techniques with very high spatial resolution can overcome this obstacle, provided that suitable contrast agents are used.

Results

We tested different contrast agents based on gold nanoparticles (AuNPs) for the detection of cancer-related angiogenesis by synchrotron microradiology, microtomography and high resolution X-ray microscopy. Among them only bare-AuNPs in conjunction with heparin injection provided sufficient contrast to allow in vivo detection of small capillary species (the smallest measured lumen diameters were 3-5 ??m). The detected vessel density was 3-7 times higher than with other nanoparticles. We also found that bare-AuNPs with heparin allows detecting symptoms of local extravascular nanoparticle diffusion in tumor areas where capillary leakage appeared.

Conclusions

Although high-Z AuNPs are natural candidates as radiology contrast agents, their success is not guaranteed, in particular when targeting very small blood vessels in tumor-related angiography. We found that AuNPs injected with heparin produced the contrast level needed to reveal--for the first time by X-ray imaging--tumor microvessels with 3-5 ??m diameter as well as extravascular diffusion due to basal membrane defenestration. These results open the interesting possibility of functional imaging of the tumor microvasculature, of its development and organization, as well as of the effects of anti-angiogenic drugs.     

Taking the devil into your mouth: ritualized American weight-loss narratives of morality, pain, and betrayal

Abstract:This article examines narratives of the U.S. Christian weight-loss movement alongside secular U.S. weight-loss narratives and explores how these two movements express similar themes. In particular, I investigate shared themes of sin, the impurity of the body, the body as a temple for the self (a temple that can be defiled), salvation, and the need to prove that one is saved or at least trying to be saved. Through examining stories from individuals who have lost weight and popular dieting advice, I explore how a "spiritual hunger" that is essentially unrelated to physiology but that suggests personal pathology and responsibility is central to mainstream stories of weight loss.     

Effects of a 12-wk resistance exercise program on skeletal muscle strength in children with burn injuries.

The posttraumatic response to burn injury leads to marked and prolonged skeletal muscle catabolism and weakness, which persist despite standard rehabilitation programs of occupational and physical therapy. We investigated whether a resistance exercise program would attenuate muscle loss and weakness that is typically found in children with thermal injury. We assessed the changes in leg muscle strength and lean body mass in severely burned children with >40% total body surface area burned. Patients were randomized to a 12-wk standard hospital rehabilitation program supplemented with an exercise training program (n = 19) or to a home-based rehabilitation program without exercise (n = 16). Leg muscle strength was assessed before and after the 12-wk rehabilitation or training program at an isokinetic speed of 150 degrees /s. Lean body mass was assessed using dual-energy X-ray absorptiometry. We found that the participation in a resistance exercise program results in a significant improvement in muscle strength, power, and lean body mass relative to a standard rehabilitation program without exercise.     

Effect of exogenous growth hormone and exercise on lean mass and muscle function in children with burns.

We tested the hypothesis that the administration of recombinant human growth hormone (rHGH) and exercise would increase lean body mass (LBM) and muscle strength in burned children to a greater extent than rHGH or exercise separately. Children, ages 7-17 yr, with >40% body surface area burned, were randomized into groups. One group (GHEX, n = 10) participated in a 12-wk in-hospital physical rehabilitation program supplemented with an exercise program and received 0.05 mg. kg(-1). day(-1) of rHGH. A second exercising group (SALEX, n = 13) received saline. A third group (GH, n = 10) received a similar dose of rHGH as GHEX and participated in a 12-wk, home-based physical rehabilitation program without exercise. The fourth group (Saline, n = 11) received saline and participated in a 12-wk, home-based physical rehabilitation program without exercise. The mean (+/-SE) percent change in lean body mass after 12 wk was not significantly different between GHEX (9.0 +/- 2.1%), SALEX (5.4 +/- 1.6%), and GH (5.8 +/- 1.8%) groups (P = 0.33). However, the mean percent change in muscle strength was significantly greater in the GHEX (36.2 +/- 5.4%) and SALEX (42.6 +/- 10.0%) groups than in the GH (-7.4 +/- 4.7%) or Saline (6.7 +/- 4.4%) groups (P = 0.008). In summary, rHGH GHEX, SALEX, and GH alone produced similar improvements in LBM. However, muscle strength was only increased via exercise.     

The cell biology of thrombospondin-1.

Thrombospondin-1 (TSP-1) is a matricellular protein that regulates cellular phenotype during tissue genesis and repair. It acts as a molecular facilitator by bringing together cytokines, growth factors, matrix components, membrane receptors and extracellular proteases. TSP-1 binds to a wide variety of integrin and non-integrin cell surface receptors. The binding sites for these receptors on TSP-1 are dispersed throughout the molecule, with most domains binding multiple receptors. In some cases, TSP-1 binds to multiple receptors concurrently, and recent data indicate that there is cross-talk between the receptor systems. Thus, TSP-1 may function to direct the clustering of receptors to specialized domains for adhesion and signal transduction.     

Towards a comprehensive barcode library for arctic life - Ephemeroptera, Plecoptera, and Trichoptera of Churchill, Manitoba, Canada

Background

In order to understand the role of herbivores in trophic webs, it is essential to know what they feed on. Diet analysis is, however, a challenge in many small herbivores with a secretive life style. In this paper, we compare novel (high-throughput pyrosequencing) DNA barcoding technology for plant mixture with traditional microhistological method. We analysed stomach contents of two ecologically important subarctic vole species, Microtus oeconomus and Myodes rufocanus, with the two methods. DNA barcoding was conducted using the P6-loop of the chloroplast trnL (UAA) intron.

Results

Although the identified plant taxa in the diets matched relatively well between the two methods, DNA barcoding gave by far taxonomically more detailed results. Quantitative comparison of results was difficult, mainly due to low taxonomic resolution of the microhistological method, which also in part explained discrepancies between the methods. Other discrepancies were likely due to biases mostly in the microhistological analysis.

Conclusion

We conclude that DNA barcoding opens up for new possibilities in the study of plant-herbivore interactions, giving a detailed and relatively unbiased picture of food utilization of herbivores.     

Lymphocytes from SJL/J mice immunized with spinal cord respond selectively to a peptide of proteolipid protein and transfer relapsing demyelinating experimental autoimmune encephalomyelitis.

Relapsing experimental autoimmune encephalomyelitis (R-EAE) can be induced in SJL/J mice by immunization with spinal cord homogenate and adjuvant. The specific Ag(s) responsible for acute disease and subsequent relapses in this model is unknown. Myelin basic protein (BP), an encephalitogenic peptide of BP (BP 87-99), and proteolipid protein (PLP) can each induce R-EAE in SJL/J mice, and a peptide of PLP (PLP 139-151) has been reported to induce acute EAE. To determine the encephalitogens in cord-immunized mice with R-EAE, the in vitro proliferative responses of lymph node cells (LNC) and central nervous system mononuclear cells to BP, BP peptides, and PLP peptides were examined during acute EAE and during relapses. LNC responded only to PLP peptides 139-151 and 141-151 and did not respond to BP or its peptides during acute or chronic disease. Central nervous system mononuclear cells also preferentially responded to PLP 139-151 and 141-151 during acute and relapsing disease. A PLP 139-151 peptide-specific Th cell line was selected from LNC of cord-immunized donors. Five million peptide-specific line cells transferred severe relapsing demyelinating EAE to naive recipients. We conclude that PLP peptide 139-151 is the major encephalitogen for R-EAE in cord-immunized SJL/J mice. We demonstrate for the first time that Th cells specific for this peptide are sufficient to transfer relapsing demyelinating EAE. The predominance of a PLP immune response rather than a BP response in SJL/J mice suggests that genetic background may determine the predominant myelin Ag response in human demyelinating diseases such as multiple sclerosis.