Effects of pressure relief holes on coal burst:Insights from true-triaxial unloading tests

Drilling pressure relief is one of the methods to reduce the risk of coal bursts in deep mines.However,the effect of the drill hole orientations has not been studied well enough to understand their impact on the burst failure mechanism.In this study,we investigated two designs of drill hole orientations.The first design includes drill holes located on the upper free face of the rectangular samples and labelled as upper hole(UH)and centre hole(CH)e the long axes of the drill holes are aligned with minor principal stress,s3,direction.The second design includes drill holes at the top(TH)and the side(SH)of the rectangular samples in which the long axes of the drill holes are aligned with the maximum,s1,and intermediate principal stress,s2,directions,respectively.The coal samples with the proposed drill hole orientations were subjected to the true-triaxial unloading coal burst tests.The results show that the drill holes reduce the risk of coal bursts.However,we found that the intensity of coal burst was significantly reduced with the SH-type,followed by the CH-types.We also observed that the coal burst intensity is reduced better for the CH,UH,TH,and SH-type drilling patterns.However,it was found that the orientations of drill holes have little influence on the failure mode(splitting).The acoustic emission(AE)activities for coal with drill holes noticeably decreased,especially for the UH and CH layouts.The drill holes reduced the upper limit of the AE entropy(chaos of microcracks generation).However,regarding reducing the coal burst risk,the TH and SH are less effective than UH and CH.

Estimation of spatial and temporal changes in net primary production based on Carnegie Ames Stanford Approach(CASA) model in semi-arid rangelands of Semirom County, Iran

Net primary production(NPP) is an indicator of rangeland ecosystem function. This research assessed the potential of the Carnegie Ames Stanford Approach(CASA) model for estimating NPP and its spatial and temporal changes in semi-arid rangelands of Semirom County, Iran. Using CASA model, we estimated the NPP values based on monthly climate data and the normalized difference vegetation index(NDVI) obtained from the MODIS sensor. Regression analysis was then applied to compare the estimated production data with observed production data. The spatial and temporal changes in NPP and light utilization efficiency(LUE) were investigated in different rangeland vegetation types. The standardized precipitation index(SPI) was also calculated at different time scales and the correlation of SPI with NPP changes was determined. The results indicated that the estimated NPP values varied from 0.00 to 74.48 g C/(m^2·a). The observed and estimated NPP values had different correlations, depending on rangeland conditions and vegetation types. The highest and lowest correlations were respectively observed in Astragalus spp.-Agropyron spp. rangeland(R^2=0.75) with good condition and Gundelia spp.-Cousinia spp. rangeland(R^2=0.36) with poor and very poor conditions. The maximum and minimum LUE values were found in Astragalus spp.-Agropyron spp. rangeland(0.117 g C/MJ) with good condition and annual grassesannual forbs rangeland(0.010 g C/MJ), respectively. According to the correlations between SPI and NPP changes, the effects of drought periods on NPP depended on vegetation types and rangeland conditions. Annual plants had the highest drought sensitivity while shrubs exhibited the lowest drought sensitivity. The positive effects of wet periods on NPP were less evident in degraded areas where the destructive effects of drought were more prominent. Therefore, determining vegetation types and rangeland conditions is essential in NPP estimation. The findings of this study confirmed the potential of the CASA for estimating rangeland production. Therefore, the model output maps can be used to evaluate, monitor and optimize rangeland management in semi-arid rangelands of Iran where MODIS NPP products are not available.

Role of polyethylene particles in peri-prosthetic osteolysis:A review

There is convincing evidence that particles produced by the wear of joint prostheses are causal in the periprosthetic loss of bone,or osteolysis,which,if it progresses,leads to the phenomenon of aseptic loosening.It is important to fully understand the biology of this bone loss because it threatens prosthesis survival,and loosened implants can result in peri-prosthetic fracture,which is disastrous for the patient and presents a difficult surgical scenario.The focus of this review is the bioactivity of polyethylene(PE)particles,since there is evidence that these are major players in the development and progression of osteolysis around prostheses which use PE as the bearing surface.The review describes the biological consequences of interaction of PE particles with macrophages,osteoclasts and cells of the osteoblast lineage,including osteocytes.It explores the possible cellular mechanisms of action of PE and seeks to use the findings to date to propose potential nonsurgical treatments for osteolysis.In particular,a nonsurgical approach is likely to be applicable to implants containing newer,highly cross-linked PEs(HXLPEs),for which osteolysis seems to occur with much reduced PE wear compared with conventional PEs.The caveat here is that we know little as yet about the bioactivity of HXLPE particles and addressing this constitutes our next challenge.

Influence of towing speed on effectiveness of rolling dynamic compaction

The influence of towing speed on the effectiveness of the 4-sided impact roller using earth pressure cells(EPCs)is investigated.Two field trials were undertaken;the first trial used three EPCs placed at varying depths between 0.5 m and 1.5 m with towing speeds of 9-12 km/h.The second used three EPCs placed at a uniform depth of 0.8 m,with towing speeds of 5-15 km/h.The findings from the two trials confirmed that towing speed influences the pressure imparted to the ground and hence compactive effort.This paper proposes that the energy imparted to the ground is best described in terms of work done,which is the sum of the change in both potential and kinetic energies.Current practice of using either kinetic energy or gravitational potential energy should be avoided as neither can accurately quantify rolling dynamic compaction(RDC)when towing speed is varied.

Structure optimization of gas-liquid combined loop reactor using a CFD-PBE coupled model

Flow characteristics, such as flow pattern, gas holdup, and bubble size distribution, in an internal loop reactor with external liquid circulation, are simulated to investigate the influence of reactor internals by using the computational fluid dynamics （CFD）-population balance equations （PBE） coupled model. Numerical results reveal that introducing a downcomer tube and a draft tube can help to improve the mass and heat transfer of the reactor through enhanced liquid circulation, increased gas holdup and reduced bubble diameter. The hydrodynamic behavior in the internal loop reactor with external liquid circulation can be managed effectively by adjusting the diameter and axial position of the draft tube.

CFD-PBE simulation of gas-phase hydrodynamics in a gas-liquid-solid combined loop reactor

The computational fluid dynamics （CFD）-population balance equations （PBE） coupled model is employed to investigate the hydrodynamics in a gas-slurry internal loop reactor with external slurry circulation. The predicted radial profiles of local gas holdup and bubble diameter are in good agreement with the corresponding experimental data. The spatio-temporal velocity profile of the gas phase reveals that the upward movement of gas is slowed down and the residence time of gas is prolonged by the downward momentum of the slurry, introduction of the external slurry can greatly improve the uniformity of gas holdup distribution in the reactor, especially in the downcomer-tube action region. Moreover, the interaction between the downward slurry and upward gas can lead to small bubble size and high interfacial area as well as good mass and heat transfer. The above results suggest the function of external slurry circulation for the internal loop reactor and would be helpful for optimizing the design and scale up of reactors.

Satisfaction with patient-doctor relationships in inflammatory bowel diseases:Examining patient-initiated change of specialist

AIM:To assess the reasons for,and factors associated with,patient-initiated changes in treating specialist in inflammatory bowel diseases(IBD).METHODS:Prospectively identified IBD patients(n = 256) with ≥ 1 encounter at a metropolitan hospital were surveyed,including whether they had changed treating specialist and why.Negative reasons included loss of confidence,disagreement,and/or personality clash with the specialist.RESULTS:Of 162 respondents,70(43%) had ever changed specialists;30/70(43%) for negative reasons,52/70(74%) in the preceding year.Patients with negative reasons for changing(n = 30) were younger(median,35.2 years vs 45.3 years),had higher IBD knowledge(median,5.0 years vs 4.0 years),yet had lower medication adherence and satisfaction scores(median,19.0 years vs 22.0 years,14.0 years vs 16.0 years respectively,Mann-Whitney tests,all P < 0.05),compared to all other responders(n = 132).Patients with a recent change(for any reason) were more likely to have Crohn's disease,currently active disease,previous bowel resection and recent hospitalization [OR 2.6,95% CI(1.3-5.4),2.2(1.0-4.7),5.56(1.92-16.67),2.0(1.3-3.0),eachP < 0.05].CONCLUSION:Changing specialist appears associated with patient-related(age,nonadherence) and contemporaneous disease-related factors(recent relapse) which,where modifiable,may enhance patient-doctor relationships and therefore quality of care.

Transcriptome profiling reveals phase-specific gene expression in the developing barley inflorescence

The shape of an inflorescence varies among cereals,ranging from a highly branched panicle in rice to a much more compact spike in barley(Hordeum vulgare L.)and wheat(Triticum aestivum L.).However,little is known about the molecular basis of cereal inflorescence architecture.We profiled transcriptomes at three developmental stages of the barley main shoot apex—spikelet initiation,floral organ differentiation,and floral organ growth—and compared them with those from vegetative seedling tissue.Transcript analyses identified 3688 genes differentially transcribed between the three meristem stages,with a further 1394 genes preferentially expressed in reproductive compared with vegetative tissue.Coexpression assembly and Gene Ontology analysis classified these 4888 genes into 28 clusters,revealing distinct patterns for genes such as transcription factors,histone modification,and cell-cycle progression specific for each stage of inflorescence development.We also compared expression patterns of VRS(SIX-ROWED SPIKE)genes and auxin-,gibberellic acid-and cytokinin-associated genes between two-rowed and six-rowed barley to describe regulators of lateral spikelet fertility.Our findings reveal barley inflorescence phase-specific gene expression,identify new candidate genes that regulate barley meristem activities and flower development,and provide a new genetic resource for further dissection of the molecular mechanisms of spike development.

WHAT IS AFFORDABLE GREEN HOUSING?ANALYSIS OF A COMPETITION

The range and invention of architects’proposals for more‘sustainable’modes of medium-density urban housing can be seen in entries to a design competition for‘affordable green housing’.The paper examines the attitudes and judgments about design that they represent,and how the winning entry has been modified for construction.An appendix provides a list of features claimed to promote the‘sustainability’of entries.The results present a picture of current thinking on the nature of affordable green housing,and provide a useful comparison for architects approaching their own projects and competition entries.

黄土高原旱地小麦与豆科绿肥轮作及施氮对小麦产量和籽粒养分的影响

小麦与豆科绿肥轮作和合理施用氮肥对黄土高原旱地缺素地区具有特别重要意义。本试验以夏休闲为对照,比较了小麦与绿豆、大豆、秋豆轮作和氮肥水平（0、108、1351、62 kg/hm2）对小麦产量和籽粒养分的影响。结果表明,小麦与豆科绿肥轮作,在黄土高原旱地受水分限制影响,小麦产量降低9.7%~26.6%;同时,与休闲处理相较,小麦籽粒养分携出量显著降低或表现出降低的趋势,其中,与绿豆轮作,小麦籽粒养分携出量降低最多,为10.5%~29.3%,大豆次之,为3.1%~12.8%,与当地大豆品种秋豆轮作,小麦籽粒养分携出量降低最少,为0.98%~11.7%。然而,小麦籽粒营养元素锌、磷、钾、钙、镁的含量与休闲处理相比,分别增加22.0%、18.5%、8.8%、7.9%、7.8%。小麦与绿肥轮作后,108 kg N/hm2（当地常规施氮量的80%）获得了较高小麦生物量和产量。同时,随施氮量的增加,小麦籽粒氮、硫、钙、铁、铜、锌的含量和养分携出量均表现出增加趋势;小麦籽粒含磷量和养分携出量有下降趋势;小麦籽粒锰含量呈现降低趋势但养分携出量增加;钾、镁的含量和养分携出量随施氮量无显著变化。

点力和线力作用下的结构振动响应研究

建立了平板结构在点力载荷和线力载荷作用下振动响应的理论模型 ,应用该模型计算出简支平板在两种载荷作用下的振动响应 ,然后进行比较分析。通过实验研究了点力载荷与实际惯性激振器产生的线力载荷作用下简支平板振动频响函数的差别。研究表明 ,点力载荷和线力载荷作用下的振动响应有一定差别 ,线力作用的圆环直径越大 ,这种差别越大 ,且高频段较低频段表现更为明显。

几个牛肉品质性状的QTL分析

测定了利木赞×娟姗牛杂交一代3头公牛所有回交后代的背最长肌和半腱肌的剪切力、pH值及煮 制损失3个表型性状,与已构建的遗传连锁图谱和基因型值相结合,利用QTL Express软件的“Half-Sib QTL Analysis Servlet”进行QTL分析。共发现6个可能的QTL位点,其中背最长肌剪切力性状3个QTL(BTA2 45 cM,BTA29 54 cM)、半腱肌剪切力1个QTL(BTA2 12 cM)、半腱肌pH值1个QTL(BTA24 0 cM)、背最长肌 煮制损失1个QTL(BTA142 cM)。

Arsenic uptake by arbuscular mycorrhizal maize (Zea mays L.) grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal （AM） fungus （Glomus mosseae） and phosphorus （P） addition （100 mg/kg soil） on arsenic （As） uptake by maize plants （Zea mays L.） from an As-contaminated soil were examined in a glasshouse experiment. Non-mycorrhizal and zero-P addition controls were included. Plant biomass and concentrations and uptake of As, P, and other nutrients, AM colonization, root lengths, and hyphal length densities were determined. The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium. Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments, but shoot and root biomass of AM plants was depressed by P application. AM fungal inoculation decreased shoot As concentrations when no P was added, and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition, respectively. Shoot and root uptake of P, Mn, Cu, and Zn increased, but shoot Fe uptake decreased by 44.6%, with inoculation, when P was added. P addition reduced shoot P, Fe, Mn, Cu, and Zn uptake of AM plants, but increased root Fe and Mn uptake of the nonmycorrhizal ones. AM colonization therefore appeared to enhance plant tolerance to As in low P soil, and have some potential for the phytostabilization of As-contaminated soil, however, P application may introduce additional environmental risk by increasing soil As mobility.

Carbon dioxide insufflation during colonoscopy in deeply sedated patients

AIM:To compare the impact of carbon dioxide(CO2) and air insufflation on patient tolerance/safety in deeply sedated patients undergoing colonoscopy.METHODS:Patients referred for colonoscopy were randomized to receive either CO2 or air insufflation during the procedure.Both the colonoscopist and patient were blinded to the type of gas used.During the procedure,insertion and withdrawal times,caecal intubationrates,total sedation given and capnography readings were recorded.The level of sedation and magnitude of patient discomfort during the procedure was assessed by a nurse using a visual analogue scale(VAS)(0-3).Patients then graded their level of discomfort and abdominal bloating using a similar VAS.Complications during and after the procedure were recorded.RESULTS:A total of 142 patients were randomized with 72 in the air arm and 70 in the CO2 arm.Mean age between the two study groups were similar.Insertion time to the caecum was quicker in the CO2 group at 7.3 min vs 9.9 min with air(P = 0.0083).The average withdrawal times were not significantly different between the two groups.Caecal intubation rates were 94.4% and 100% in the air and CO2 groups respectively(P = 0.012).The level of discomfort assessed by the nurse was 0.69(air) and 0.39(CO2)(P = 0.0155) and by the patient 0.82(air) and 0.46(CO2)(P = 0.0228).The level of abdominal bloating was 0.97(air) and 0.36(CO2)(P = 0.001).Capnography readings trended to be higher in the CO2 group at the commencement,caecal intubation,and conclusion of the procedure,even though this was not significantly different when compared to readings obtained during air insufflation.There were no complications in both arms.CONCLUSION:CO2 insufflation during colonoscopy is more efficacious than air,allowing quicker and better cecal intubation rates.Abdominal discomfort and bloating were significantly less with CO2 insufflation.

Proximal gastric response to small intestinal nutrients is abnormal in mechanically ventilated critically ill patients

AIM： To determine the response of the proxima stomach to small intestinal nutrients in critically ill patients. METHODS： Proximal gastric motility was measured in 13 critically ill patients （49.3 ± 4.7 years） and 12 healthy volunteers （27.7 ± 2.9 years） using a barostat technique. Recordings were performed at baseline, during a 60-rain intra-duodenal infusion of Ensure^R （2 kcal/min）, and for 2 h following the infusion. Minimum distending pressure （MDP）, intra-bag volume and fundic wave activity were determined. RESULTS： The MDP was higher in patients （11.7 ± 1.1 vs 7.8 ± 0.7 mmHg; P 〈 0.01）. Baseline intrabag volumes were similar in the 2 groups. In healthy subjects, a ‘bimodal＇ proximal gastric volume response was observed. In patients, the initial increase in proximal gastric volume was small and delayed, but eventually reached a maximal volume similar to that of healthy subjects. In healthy subjects, the proximal gastric volume rapidly returned to baseline level after nutrient infusion （median 18 min）. In contrast, the recovery of volume to baseline was delayed in critically ill patients （median 106 min）. In 6 patients, the volume had not returned to baseline level 2 hours after nutrient infusion. In patients, fundic volume waves were less frequent （P 〈 0.05） and had lower amplitude （P 〈 0.001）, compared to healthy subjects. CONCLUSION： In critical illness, proximal gastric motor responses to small intestinal nutrient stimulation are abnormal.

Distal small bowel motility and lipid absorption in patients following abdominal aortic aneurysm repair surgery

AIM： To investigate distal small bowel motility and lipid absorption in patients following elective abdominal aortic aneurysm （AAA） repair surgery, METHODS： Nine patients （aged 35-78 years; body mass index （BMI） range： 23-36 kg/m2） post-surgery for AAA repair, and seven healthy control subjects （20-50 years; BMI range： 21-29 kg/m^2） were studied, Continuous distal small bowel manometry was performed for up to 72 h, during periods of fasting and enteral feeding （Nutrison）. Recordings were analyzed for the frequency, odgin, length of migration, and direction of small intestinal burst activity. Lipid absorption was assessed on the first day and the third day post surgery in a subset of patients using the ^13C-triolein-breath test, and compared with healthy controls. Subjects received a 20-min intraduodenal infusion of 50 mL liquid feed mixed with 200μL ^13C-triolein. End-expiratory breath samples were collected for 6 h and analyzed for ^13CO2 concentration. RESULTS： The frequency of burst activity in the proximal and distal small intestine was higher in patients than in healthy subjects, under both fasting and fed conditions （P〈 0.005）. In patients there was a higher proportion of abnormally propagated bursts （71% abnormal）, which began to normalize by d 3 （25% abnormal） post-surgery.Lipid absorption data was available for seven patients on d 1 and four patients on d 3 post surgery. In patients, absorption on d 1 post-surgery was half that of healthy control subjects （AUC ^13CO2 1323±244 vs 2646±365; P〈0.05, respectively）, and was reduced to the one-fitch that of healthy controls by d 3 （AUC ^13CO2 470±832 vs 2646±365; P〈 0.05, respectively）. CONCLUSION： Both proximal and distal small intestinal motor activity are transiently disrupted in critically ill patients immediately after major surgery, with abnormal motility patterns extending as far as the ileum. These motor disturbances may contribute to impaired absorption of enteral nutrition, especially when intraluminal processing is necessary for efficient digestion.

Plasma-electrochemical synthesis of europium doped cerium oxide nanoparticles

In the present study,a plasma-electrochemical method was demonstrated for the synthesis of europium doped ceria nanoparticles.Ce(NO3)3· 6H2O and Eu(NO3)3·5H2O were used as the starting materials and being dissolved in the distilled water as the electrolyte solution.The plasma-liquid interaction process was in-situ investigated by an optical emission spectroscopy,and the obtained products were characterized by complementary analytical methods.Results showed that crystalline cubic CeO2:Eu3+ nanoparticles were successfully obtained,with a particle size in the range from 30 to 60 nm.The crystal structure didn't change during the calcination at a temperature from 400℃ to 1000℃,with the average erystallite size being estimated to be 52 nm at 1000℃.Eu3+ ions were shown to be effectively and uniformly doped into the CeO2 lattices.As a result,the obtained nanophosphors emit apparent red color under the UV irradiation,which can be easily observed by naked eye.The photoluminescence spectrum further proves the downshift behavior of the obtained products,where characteristic 5Do → 7F1,2,3 transitions of Eu3+ ions had been detected.Due to the simple,flexible and environmental friendly process,this plasma-electrochemical method should have great potential for the synthesis of a series of nanophosphors,especially for bio-application purpose.

Functional response and predation of Nabis kinbergii （Hemiptera. Nabidae） to Plutella xylostella （Lepidoptera. Plutellidae）

The functional response of adult Nabis kinbergii （Hemiptera： Nabidae） to density of diamondback moth Plutella xylostella （Lepidoptera： Plutellidae） was investigated under laboratory conditions. Holling＇ s （1959） type Ⅱ model was found to be a good fit for the observed functional response of this predator. The numbers of P. xylostella consumed increased with temperature from 15℃ to 35℃. The maximum number of prey killed was observed at 35℃, with average of 10.3 and 8.3 forth instar larvae consumed by adult females and males of N. kinbergii, respectively. The predation of N. kinbergii on P. xylostella increased with successive immature stages. The number of prey consumed by predators decreased as the body size of prey increased. An average of 131 eggs or 95 larvae of P. xylostella were killed by a single of female adult in 24 hours at 24＂C. The pupae of P. xylostella were observed to be eaten by fifth instar nymphs and adults N. kinbergiiin numbers of less than an average of 0.7 pupae per predator in 24 hours at 24＂C. Predation preference by N. kinbergii was also investigated. The number of P. xylostella and Myzus persicae killed by female N. kinbergii was not significantly different, but males killed significantly more P. xylostella than M. persicae. Both eggs and larvae of P. xylosteUa were killed in significantly greater number than those of Pieris rapae in the same feeding arena.

Advanced treatment of wet-spun acrylic fiber manufacturing wastewater using three-dimensional electrochemical oxidation

A three-dimensional electrochemical oxidation （3D-EC） reactor with introduction of activated carbon （AC） as particle micro-electrodes was apphed for the advanced treatment of secondary wastewater effluent of a wet-spun acrylic fiber manufacturing plant. Under the optimized conditions （current density of 500 A/m2, circulation rate of 5 mL/min, AC dosage of 50 g, and chloride concentration of 1.0 g/L）, the average removal efficiencies of chemical oxygen demand （CODer）, NH3-N, total organic carbon （TOC）, and ultraviolet absorption at 254 nm （UV2s4） of the 3D-EC reactor were 64.5%, 60.8%, 46.4%, and 64.8%, respectively; while the corresponding effluent concentrations of CODcr, NH3-N, TOC, and UV2s4 were 76.6, 20.1, and 42.5 mg/L, and 0.08 Abs/cm, respectively. The effluent concentration of CODer was less than 100 mg/L, which showed that the treated wastewater satisfied the demand of the integrated wastewater discharge standard （GB 8978-1996）. The 3D-EC process remarkably improved the treatment efficiencies with synergistic effects for CODer, NH3-N, TOC, and UV2s4 during the stable stage of 44.5%, 38.8%, 27.2%, and 10.9%, respectively, as compared with the sum of the efficiencies of a two-dimensional electrochemical oxidation （2D-EC） reactor and an AC adsorption process, which was ascribed to the numerous micro-electrodes of AC in the 3D-EC reactor. Gas chromatography mass spectrometry （GC-MS） analysis revealed that electro- chemical treatment did not generate more toxic organics, and it was proved that the increase in acute biotoxicity was caused primarily by the production of free chlorine.

The CELLULOSE-SYNTHASE LIKE C （CSLC） Family of Barley Includes Members that Are Integral Membrane Proteins Targeted to the Plasma Membrane

The CELLULOSE SYNTHASE-LIKE C （CSLC） family is an ancient lineage within the CELLULOSE SYNTHASE/CELLULOSE SYNTHASE-LIKE （CESA/CSL） polysaccharide synthase superfamily that is thought to have arisen before the divergence of mosses and vascular plants. As studies in the flowering plant Arabidopsis have suggested synthesis of the （1,4）-β-glucan backbone of xyloglucan （XyG）, a wall polysaccharide that tethers adjacent cellulose microfibrils to each other, as a probable function for the CSLCs, CSLC function was investigated in barley （Hordeum vulgate L.）, a species with low amounts of XyG in its walls. Four barley CSLCgenes were identified （designated HvCSLC1-4）. Phylogenetic analysis reveals three well supported clades of CSLCs in flowering plants, with barley having representatives in two of these clades. The four barley CSLCs were expressed in various tissues, with in situ PCR detecting transcripts in all cell types of the coleoptile and root, including cells with primary and secondary cell walls. Co-expression analysis showed that HvCSLC3 was coordinately expressed with putative XyG xylosyltransferase genes. Both immuno-EM and membrane fractionation showed that HvCSLC2 was located in the plasma membrane of barley suspension-cultured cells and was not in internal membranes such as endoplasmic reticulum or Golgi apparatus. Based on our current knowledge of the sub-cellular locations of polysaccharide synthesis, we conclude that the CSLC family probably contains more than one type of polysaccharide synthase.