Shifts in Methanogenic Subpopulations Measured with Antibody Probes in a Fixed-Bed Loop Anaerobic Bioreactor Treating Sulfite Evaporator Condensate

A fixed-bed loop, high-rate anaerobic bioreactor treating sulfite evaporator condensate was sampled when it reached steady state and afterwards following perturbations during a 14-month period. By using immunotechnology, it was observed that shifts in methanogenic subpopulations occurred in association with perturbations, such as restarting and relocating the biomass into a different tank. Methanogens related to Methanobacterium bryantii MoHG and Methanobrevibacter smithii ALI were numerous throughout the observation period, while Methanosarcina mazei S6 and Methanosarcina thermophila TM1 were found in the early and late samples, respectively. Also, Methanobacterium formicicum was more numerous at the top portion of the bioreactor, while Methanobrevibacter arboriphilus AZ and DC were at the bottom. Sample formalinization required for prolonged storage proved suitable for antigen preservation.     

Comparative effects of trichothecene mycotoxins on bovine platelet function: Acetyl T-2 toxin,a more potent inhibitor than T-2 toxin

The effects of the trichothecene mycotoxins (acetyl T-2 toxin, T-2 toxin, HT-2 toxin, palmityl T-2 toxin, diacetoxyscirpenol (DAS), deoxynivalenol (DON), and T-2 tetraol) on bovine platelet function were examined in homologous plasma stimulated with platelet activating factor (PAF). The mycotoxins inhibited platelet function with the following order of potency: acetyl T-2 toxin > palmityl T-2 toxin = DAS > HT-2 toxin = T-2 toxin. While T-2 tetraol was completely ineffective as an inhibitor, DON exhibited minimal inhibitory activity at concentrations above 10×10^?4M. The stability of the platelet aggregates formed was significantly reduced in all mycotoxin treated platelets compared to that of the untreated PAF controls. It is suggested that the increased sensitivity of PAF stimulated bovine platelets to the more lipophilic mycotoxins may be related to their more efficient partitioning into the platelet membrane compared to the more hydrophilic compounds.     

Vertically stratified frugivore community composition and interaction frequency in a liana fruiting across forest strata

Vertical stratification is a key feature of tropical forests and structures plant–frugivore interactions. However, it is unclear whether vertical differences in plant-frugivore interactions are due to differences among strata in plant community composition or inherent preferences of frugivores for specific strata. To test this, we observed fruit removal of a diverse frugivore community on the liana Marcgravia longifolia in a Peruvian rain forest. Unlike most other plants, Marcgravia longifolia produces fruits across forest strata. This enabled us to study effects of vertical stratification on fruit removal without confounding effects of plant species and stratum. We found a high number of visits of a few frugivore species in the understorey and a low number of visits of many different frugivores in the canopy and midstorey. Whereas partial and opportunistic frugivores foraged across strata with differing frequencies, obligate frugivores were only found eating fruits in the higher strata. Avian frugivores foraging in the canopy were mainly large species with pointed wings, whereas under- and midstorey avian foragers were smaller with rounded wings. Our findings suggest a continuous shift in the frugivore community composition along the vertical gradient, from a few generalized frugivores in the understorey to a diverse set of specialized frugivores in the canopy. This shift in the frugivore community leads to correlated, reciprocal changes from specialized to generalized plant-frugivore interactions. Thus, we conclude that vertical niche differentiation between species in tropical forests persists even when food resources are available across strata. This highlights its role for promoting biodiversity and ecosystem functioning.     

The impact of surface mine reclamation on headwater streams in Southwest Virginia

Recovery of headwater streams following the cessation of mining and the application of terrestrial (vegetative) reclamation techniques was assessed by comparison of water quality and aquatic biota in two such systems (reclaimed four to seven years) with that of an unimpacted stream and of streams draining mine areas which were abandoned without reclamation. Alkalinity, hardness, sulfate, and conductivity were elevated in the reclaimed mine streams as were fine-particle suspended solids and sediment. Overall water quality was comparable to streams draining unreclaimed lands. Benthic invertebrate and fish populations were significantly lower in abundance in the reclaimed mine streams than in the reference stream and showed less taxonomic richness and stability; they were similar in these respects to the biota of the unreclaimed mine streams. Continued sedimentation from mined areas and haul roads affected stream habitat and appeared to be the major factor limiting biotic recovery. These findings emphasize that terrestrial reclamation does not assure lotic restoration. Water quality criteria merit consideration in the refinement of reclamation procedures for mined lands.     

Seed growth rate in grain legumes II. Seed growth rate depends on cotyledon cell number

Individual seed weight and seed growth rate are variable within the plant and among environmental conditions. Seed growth rate remains constant during the filling period even if assimilate availability is modified. This paper describes the relationship between the cotyledon cell number fixed at the beginning of seed filling and the seed growth rate. Two genotypes of pea were grown in various environmental conditions: field, glasshouse and growth chamber. One genotype of soybean was sown in field. Seed growth rate and cotyledon cell number were measured. Variations in seed growth rate (0.24 to 1.07 mg per degree-day for pea, 0.23 to 0.42 mg per degree-day for soybean) largely account for differences in individual seed weight. For each species, cotyledon cell number (from 3.4 x 10⁵ to 10.2 x 10⁵ per seed for pea, from 6.7 x 10⁶ to 9 x 10⁶ per seed for soybean) and seed growth rate are strongly correlated regardless of environmental conditions and intraplant position. Consequently, seed growth rate observed during the seed filling period is determined before this period during the cell division in the embryo: variations in seed growth rate depend on the growing conditions during the period between flowering and the beginning of seed filling.     

吐鲁番市胃食管反流病发生相关危险因素分析（附280例报道）

目的：探讨280例胃食管反流病（GERD）的分布特点及危险因素。方法：对临床诊断和胃镜确诊的280例GERD患者进行临床和风险因子相关性分析。结果：不论汉族还是维族,男性患者比例均明显高于女性;汉族患者高发年龄段早于维族患者（z=-2．939,P=0．003,）;汉族和维族患者占反流性食管炎和Barrett食管比例分别为42．4％、81_3％及56．5％、18．8％,其中汉族患者Barrett食管比例较高（X2=14．358,P=0．000）;肥胖、习惯性便秘、重体力活动者、饮食习惯不良在维族患者中的比例较高（P〈0．001）。结论：GERD与性别、年龄密切相关,男性多于女性,汉族患者发病年龄高峰旱于维族患者;汉族患者Barrett食管发生比例高于维族患者;肥胖、习惯性便秘、重体力活动、饮食习惯不良可能是GERD尤其是维族人群GERD的危险因素。     

Oral Ingestion of Transgenic RIDL Ae. aegypti Larvae Has No Negative Effect on Two Predator Toxorhynchites Species

Dengue is the most important mosquito-borne viral disease. No specific treatment or vaccine is currently available; traditional vector control methods can rarely achieve adequate control. Recently, the RIDL (Release of Insect carrying Dominant Lethality) approach has been developed, based on the sterile insect technique, in which genetically engineered ‘sterile’ homozygous RIDL male insects are released to mate wild females; the offspring inherit a copy of the RIDL construct and die. A RIDL strain of the dengue mosquito, Aedes aegypti, OX513A, expresses a fluorescent marker gene for identification (DsRed2) and a protein (tTAV) that causes the offspring to die. We examined whether these proteins could adversely affect predators that may feed on the insect. Aedes aegypti is a peri-domestic mosquito that typically breeds in small, rain-water-filled containers and has no specific predators. Toxorhynchites larvae feed on small aquatic organisms and are easily reared in the laboratory where they can be fed exclusively on mosquito larvae. To evaluate the effect of a predator feeding on a diet of RIDL insects, OX513A Ae. aegypti larvae were fed to two different species of Toxorhynchites (Tx. splendens and Tx. amboinensis) and effects on life table parameters of all life stages were compared to being fed on wild type larvae. No significant negative effect was observed on any life table parameter studied; this outcome and the benign nature of the expressed proteins (tTAV and DsRed2) indicate that Ae. aegypti OX513A RIDL strain is unlikely to have any adverse effects on predators in the environment.     

IGF-I augments resection-induced mucosal hyperplasia by altering enterocyte kinetics

Our objective was to determine if exogenous insulin-like growth factor-I (IGF-I) augments the adaptive growth response to mid small bowel resection in association with changes in enterocyte kinetics. We determined structural adaptation and concomitant changes in enterocyte proliferation, apoptosis, and migration of the jejunum in growing, parenterally fed rats after mid small bowel resection or small bowel transection, and treatment with IGF-I or vehicle. IGF-I treatment in resected rats significantly increased jejunal mucosal mass by 20% and mucosal concentrations of protein and DNA by 36 and 33%, respectively, above the response to resection alone. The enhancement of resection-induced adaptive growth and cellularity by IGF-I reflected an increase in enterocyte proliferation, an expansion of the proliferative compartment in the crypt, and no further decrease in enterocyte apoptosis or increase in enterocyte migration beyond the effects of resection. The ability of IGF-I to augment the mucosal hyperplasia stimulated by the endogenous response to resection substantiates the role of IGF-I as an intestinal mitogen that promotes tissue regeneration.     

Successful immunotherapy with matrix metalloproteinase-derived peptides in adjuvant arthritis depends on the timing of peptide administration

We have recently found that matrix metalloproteinases (MMPs) are targets for T-cell and B-cell reactivity in experimental arthritis. In the present article, we investigate whether modulation of MMP-specific T-cell responses could influence the course of adjuvant arthritis (AA). Lewis rats were treated nasally with MMP peptides prior to or after AA induction. Administration of the MMP-10 or the MMP-16 peptide prior to AA induction reduced the arthritic symptoms. In contrast, administration of the MMP-10 peptide after AA induction aggravated the arthritic symptoms. The present study shows the possible usefulness of MMP peptides for immunotherapy. However, a clear understanding of proper timing of peptide administration is crucial for the development of such therapies.