Main Limitation Factor Research Articles

Land suitability decision support for assessing land use changes in areas west of Nile Delta, Egypt

The main objective of this study was to discuss the efficiency of agricultural land suitability for assessing land use types in rural areas. In this research, El-Nubariya area west of Nile Delta was selected as a case study site, which considers one of the high priority regions for future development in Egypt. As input, a total of ten representative soil profiles and number of observations points were used for collecting soil samples. Based on the field survey, laboratory analysis, and satellite image interpretation in cooperation with geographic information system (GIS), the physiographic map was executed. Three main landscape units were identified as follow: marine deposits, eolian deposits, and river terraces. The soils were classified mainly as Typic Torripsamments, Typic Paleorthids, and Typic Calciorthids. Land suitability assessment was done to define maps of the suitable areas for agricultural production using MicroLEIS microcomputer program and ALESarid-GIS system as well. According to the crop suitability results, the most suitable crops to grow in the study area were maize, melon, potato, sunflower, onion, garlic, olive, and date palm in the order indicated. Generally, the data on land suitability resulting from the evaluation models indicated that 56.1 % of the area is considered as suitable, 30.8 % is moderately to marginally suitable, and 13.1 % is not suitable. The main limitation factors for land suitability are the excess of salts, shallow soil depth, and inadequate drainage conditions. The output results are presented as georeferenced soil suitability maps using GIS utilities.

Quantitative proteomic profiling reveals photosynthesis responsible for inoculum size dependent variation in Chlorella sorokiniana

High density cultivation is essential to industrial production of biodiesel from microalgae, which involves in variations of micro-environment around individual cells, including light intensity, nutrition distribution, other abiotic stress and so on. To figure out the main limit factor in high inoculum cultivation, a quantitative proteomic analysis (iTRAQ-on-line 2-D nano-LC/MS) in a non-model green microalga, Chlorella sorokiniana, under different inoculum sizes was conducted. The resulting high-quality proteomic dataset consisted of 695 proteins. Using a cutoff of P < 0.05, 241 unique proteins with differential expression levels were identified between control and different inoculum sizes. Functional analysis showed that proteins participating in photosynthesis (light reaction) and Calvin cycle (carbon reaction pathway) had highest expression levels under inoculum size of 1 × 10(6) cells mL(-1), and lowest levels under 1 × 10(7) cells mL(-1). Canonical correlation analysis of the photosynthesis related proteins and metabolites biomarkers showed that a good correlation existed between them (canonical coefficient was 0.987), suggesting photosynthesis process greatly affected microalgae biodiesel productivity and quality. Proteomic study of C. sorokiniana under different illuminations was also conducted to confirm light intensity as a potential limit factor of high inoculum size. Nearly two thirds of proteins showed up-regulation under the illumination of 70-110 µmol m(-2) s(-1), compared to those of 40 µmol m(-2) s(-1). This result suggested that by elegantly adjusting light conditions, high cell density cultivation and high biodiesel production might be achieved.

Application of Fused-Core Particle Column in Two Dimensional Reversed Phase - Reversed Phase LC/MS Analysis of Biological Samples. Impact of Extra-Column Volume

We demonstrate successful applicability of fused–core column in analysis of biological samples (diluted urine and SPE–pre-purified plasma or serum) using 2 dimensional chromatography. Implementation of fused-core material in the second dimension of 2D chromatographic platform allowed improving S/N above 4 fold in comparison to traditional porous C18 column. Sample load onto the first dimension (5 μm) eliminates limitations of sample volume to be injected. The main limitation factor of the fused-core material–low loading capacity was overcome by using 2D chromatography. We emphasize importance of reduction of post-column (extra column) volume in LC/MS applications utilizing fused-core columns.

The Land Suitability Evaluation of Cotton Based on GIS Technology

The land suitability supply the decision-making for the planning and design and rational distribution, and prevent the unreasonable use of land. In order to evaluate the land suitability of cotton, the research which makes use of ArcGIS establishes the common model including the partition of evaluation unit, the selection of evaluation factors, the determination of the weight, and form a fast, simple and practical evaluation process. The results illustrate that 61 percent of the study area are suitable for the cotton’s growth; the content of salt is the main limit factor of the cotton’s growth.

Dynamics of chlorophyll-a and analysis of environmental factors in Lake Dianshan during summer and autumn

根据2008年5-9月专项监测数据, 分析蓝藻水华高发期淀山湖叶绿素a浓度的动态变化, 及其与pH、溶解氧、TN、TP等环境因子的相互关系.结果表明, 淀山湖蓝藻水华高发期叶绿素a存在明显的时间变化和空间分异, 特别是叶绿素a的峰值共对应了3次水华暴发过程.其叶绿素a对数与总磷对数呈极显著正相关, 与硝酸盐氮、TN/TP呈负相关, 与总氮、氨氮等则无显著相关性;这表明淀山湖可能是一定程度的磷限制性湖泊.此外, 叶绿素a与水温、pH、溶解氧呈显著正相关, 与透明度存在极显著负相关。;According to the monitoring data at 13 sampling sites of Lake Dianshan from May to September 2008, the relationship between chlorophyll-a concentrations and environmental factors(water temperature, pH, DO, TN and TP) was investigated.The results indicated that there was an obvious temporal and spatial variation of chlorophyll-a.The first eyanobaeterial bloom in 2008 occurred On July 23 at Qiandungang site and Yonyongchang site.The most severe bloom covered a total area of 17km² on August 27.Significandy positive logarithmic correlation was found between chlorophyll-a and total phosphorus, but not for ammonia nitrogen.nitrate nitrogen and total nitrogen.Phosphorus might be the main limited factor in Lake Dianshan.Significantly positive correlations were found between chlorophyll-a concentration and water temperature, pH, dissolved oxygen, and markedly negative correlation between chlorophyll-a and transparency.

3413 Micro-Electrical Discharge Machining of Reaction-Bonded Silicon Carbide(RB-SiC)

Functional micro-structures are gaining more and more importance in the industrial technologies during the last few years. For example, deep micro holes find a wide range of applications in inkjet printer nozzles, spinnerets holes, turbine blades cooling channels, diesel fuel injection nozzles, drug delivery orifices, etc. Another important example is microlens arrays. The ability of microlens arrays to focus incident light into a series of beam spots makes them useful as important optical elements that are widely used in the area of optoelectronic and optical communications. Due to the wide applications of these functional micro-structures in optical, biomedical engineering and microelectromechanical systems (MEMS), micro fabrication techniques have gained growing interest from researchers and engineers. Recently, the use of reaction-bonded silicon carbide (RB-SiC) as a material in manufacturing optical molding dies for aspherical lenses and microlens arrays has become a new research focus, due to its superior material properties, such as high hardness and strength at elevated temperature, high thermal conductivity, chemical stability, wear resistance and low density. However, due to its high hardness (Vickers hardness 25-35 GPa), it is typically difficult to be machined. Although abrasive machining processes, such as lapping, polishing and grinding can produce a fine surface finish, but the machining efficiency is low and the production cost is high. Diamond cutting is able to produce a high material removal rate, but the severe tool wear in diamond cutting of RB-SiC is the main obstacle that limits its wide application in the industry. Compared to the aforementioned methods, micro electrical discharge machining (micro-EDM) has emerged as a possibly effective machining tool to fabricate complex micro-structures on hard and difficult-to-cut materials like RB-SiC. However, the use of conventional micro-EDM alone to obtain micro-structures with good surface finish and high form accuracy in RB-SiC, is still a challenging issue. The high resistivity of the RB-SiC workpiece is the main limiting factor for the discharge current of micro-EDM, which directly affects the machining efficiency of RB-SiC. The main objective of this study is to develop hybrid machining processes based on micro-EDM for improving the machinability and surface finish of RB-SiC. Carbon nanofibers assisted micro-EDM was proposed to replace the conventional micro-EDM. The effects of carbon nanofibers addition in the dielectric fluid were confirmed experimentally. The machining mechanism and the material migration phenomenon with the addition of carbon nanofibers were investigated and clarified. Next, a novel machining process, namely hybrid micro-EDM process by combining ultrasonic cavitation and carbon nanofibers was proposed, in order to improve the machining efficiency of RB-SiC ceramic material and to prevent from tool material deposition on workpiece. The effectiveness of the hybrid process was verified through the fabrication of micro-structures on RB-SiC. This thesis consists of five chapters. Chapter 1 gives an overview of the background of this research. Firstly, an introduction of the RB-SiC ceramic material, including the fabrication process, material properties, applications and previous machining processes of RB-SiC material were given. EDM was chosen as a method to fabricate micro-structures on the RB-SiC, which can overcome the shortcomings of the abrasive machining process. Then, an overview of the principle of micro-EDM/EDM process was discussed. The problem of machining RB-SiC by using conventional EDM was also pointed out. Some recent developments for enhancing the machinability of hard and brittle ceramic materials by micro-EDM/EDM were reviewed. Finally the objectives and organization of this thesis were stated.

Effect of Temperature on the Catalytic Ability of Electrochemically Active Biofilm as Anode Catalyst in Microbial Fuel Cells

AbstractIn this study we report the effect of temperature on the catalytic ability of an electrochemically active biofilm based on mixed‐culture to oxidize acetate and found the optimum temperature showing maximal catalytic activity and power output. Electrochemical characterization of biofilm and power output and internal resistance of microbial fuel cell (MFC) have been investigated at different temperatures. When temperature increased from 30 to 45 °C the catalytic ability of biofilms to oxidize acetate increased following the Arrhenius law with apparent activation energy of 44.85 kJ/mol. At temperatures higher than 48 °C, however, the bioelectrocatalytic current decreased. At 53 °C the bacterial metabolism was in inactivation. The optimum working temperature of the biofilm was 45 °C, producing current of 1339 µA cm−2. This current was almost three times higher than 527 µA cm−2 at 30 °C. The MFC performance at different temperatures showed consistent temperature dependence to that of a semi‐batch cell, which implies that anode catalytic ability in MFC is the main limit factor for increasing power output. A maximum power output of 1065 mW m−2 was also observed at 45 °C and it was 1.5 times higher than 764 mW m−2 at 30 °C. The increased MFC performance from 30 °C to 45 °C is lower in comparison with about three times higher increase in semi‐batch cells. This could be due to other factors such as proton migration rate in membrane of MFC, which can be seen from that the internal resistance value of 121.5 Ω in the MFC at 45 °C was only slightly lower than 177.6 Ω at 30 °C. Also, some other factors such as cell configuration which would limit the power output and can be further optimized. This work contributes to the study of influence from temperature on anodic electrochemically active biofilm activity and their subsequent influence on MFC performance and reports the optimal temperature for biofilm activity based on mixed‐culture.

The present use of soil and water in the basin of the creek Piçarrão-Araguari-MG-Brazil

The agricultural expansion in the basin of the creek Picarrao during the period from 1970 to 2005 produced changes in the use of soil and water that heretofore had not been documented. A diagnosis of the present situation was carried out to evaluate the prospect of agricultural activity in the basin. The literature was reviewed, 16 rural producers were interviewed, and the creek and its tributaries were inspected. The results of the study are presented in form of maps and tables. The total area drained by the creek is 388 km2, nine pivots do the agricultural irrigation, and the creek’s flow rate varies between 1.5 and 80.0 m3 per second with an annual average of 8.0 m3 per second. The study identified water availability as main limiting factor of agricultural development in the basin.

연속주조기의 몰드 폭 변경 패턴 개발

연속주조 시에 폭변경 속도를 향상시키기 위해 폭조정의 4 가지 패턴에 대해 연구하였다. 주요 사항은 폭변경 장치의 구동력을 최소화하고, 몰드 내의 응고막의 변형해석 모델을 개발하고, 폭변경 속도 상승을 제한하는 주요인자를 도출하는 것이다. 폭변경 실험을 근간으로 4 개 패턴의 주요 특징을 도출하였고, 각 패턴에 대한 힘을 비교하였다. 실험은 각 패턴의 구동력 비교를 위해 동일한 주조속도에서 수행하였다. 응고막 변형 해석모델의 변수를 조정하기 위해 실험결과를 모델에 적용하였다. 폭변경 속도를 상승시키고, 구동력을 저감시키기 위해 패턴의 변수를 제어하였다. 가장 효율적인 패턴은 고속패턴이었으며, 구동력을 저감하기 위한 주요인자는 구동장치가 이동할 때의 기울기였다.

A new modular feeding system and its economic scope of application

Since flexible production systems usually require special technologies and additional components, high costs are the main limitation factor for their flexibility. Therefore, the most economic components have to be chosen for each flexible production system. This paper focuses on automatic feeding systems and starts with a comparison of the flexibility and the feeding rates of the most important flexible feeders available today. To cope with the deficits of flexible feeders with mechanical orientation, a new modular system is presented. In addition, a design method for the different modules of the new feeder is introduced. Finally, a detailed cost analysis determines the economic application of the modular feeder within the presented systems in dependency of the given flexible feeding task.

Impact On Mother-Baby Parameters in Total Nuclear and CD34+ Cell Count in Umbilical Cord Blood Banking.

Abstract 3221Poster Board III-158 IntroductionUmbilical cord blood (UCB) has become an easily, available and viable source of hematopoeitic stem cells for transplant. The main limitation factor for its wide use is cell dose. Previous studies have showed that certain physiological parameters pertaining to either the baby or the mother impact in the UCB cell yields. ObjectivesThe aim of our study was to compare five physiological parameters pertaining to the mother or baby (mother`s age [MA], gestational age at delivery [GA], baby`s gender [G], baby`s birth weight [BW] and type of delivery [TD]) with total nuclear cells (TNC) and CD34 + cells recovery. We also evaluated the impact of time from collection to processing (TCP) on CD45+ cells viability. MethodsUCB product collection was performed after the baby's delivery, while the placenta was still in uterus, either from vaginal or cesarean deliveries. Collection bags that were used contained 35 mL of CFDA-1 (CFD with Adenina) as anticoagulant. Cord blood units (CBU) were processed in our institution under local and international regulations regarding cord blood banking. Usual techniques with HES 6% for red cell depletion and 4°C centrifugation for plasma depletion were used. Twenty-five ml, EVA, two-compartment cord blood cells freezing bags (Pall Medical) were used for a final CBU volume of 20.5 ml combined with Dextran 40/40 and DMSO for cryopreservation. A sample was removed for flow cytometric analysis (BD FACSCan) and to determine the TNC (Cell-dyn 1200). Cultures pre and post CBU handling were done. Freezing took place in a controlled-rate freezer according to standard protocol before storage in liquid nytrogen. ResultsFrom May 2004 to Jun 2009, a total of 4,262 continous UCB collections were performed in our institution throught the Peruvian Republic. Seventy-eight percent of the CBU were collected by cesarean; median TCP was 30 hours 58 minutes. The mean CBU volume and TNC count were 81.8 ml and 8.63 × 108 respectively. The colected volume was greater in cesarean than vaginal delivery (85.3 ml vs 78.9, F=30.82, p<0.001). TNC counts collected were directly correlated with GA: in preterm delivery (<37sem) was 7.13×108, in term delivery (>=37sem) was 9.93×108. TNC counts were directly correlated with BW (F=325, p<0.001) while the MA had inverse correlation (F=8.05, p=0.005); regarding TD there was a significant mayor TNC count in the vaginal vs. cesarean group (10.49×108 vs. 9.22×108, F=48.207, p<0.001); while it was a trend for major TNC count in females vs. males babies (9.82×108 vs. 9.13×108, p=0.059). CD34+ cells count was directly correlated with BW (F=70.1, p<0.001). The strongest correlation was with GA (in preterm: 61.99 CD34+/ul and in term delivery: 84.67 CD34+/ul, F=27.62 p=<0.001); moreover, there was association between CD34+ cells count with TD (vaginal: 87.88 CD34+/ul vs cesarean: 80.26 CD34+/ul, F=5.327 p=0.02). There was not association either with G (females: 79.97 CD34+/ul vs males: 83.48 CD34+/ul, F=1.668 p=0.197) neither MA (F=1.82, p=0.177). There was a significant difference between CD34+ viability cells among CBU with less than 48 hours or more of TCP (99.6% vs. 99.4%, p=0.019); this difference was stronger when the CD45+ viability was evaluated (93.35% vs. 90.14%, p<0,001). ConclusionsTNC and CD34+ UCB cells are influenced by many variables related to the mother and the baby. It looks like on time female babies with good weight, born to a younger mother and from a vaginal delivery reach highest TNC count. CD34+ cells count was directly correlated with BW and CD34+ viability is mainly influenced by the time from collection to processing DisclosuresNo relevant conflicts of interest to declare.

Fire-driven oak regeneration in French Mediterranean ecosystems

Regeneration by seeds for cork oak ( Quercus suber) and companion oaks (holm oak Quercus ilex and downy oak Quercus pubescens) is likely to be poor in the fire-prone Maures massif (southern France) but the causes are poorly known. Our objective was to assess the effective recruitment for these three oak species and their temporal pattern of recruitment, in order to determine the main limitation factors and the regeneration window of each species. We studied oak recruits (height <3 m) in naturally regenerated populations according to a gradient of fire recurrence and in five main vegetation types including shrublands and mixed mature woodlands. Fire recurrence was the main explanatory factor of oak recruitment, either directly or through vegetation type and microsite characteristics. The results indicate nil to low recruitment for holm oak and downy oak in shrublands, especially those recurrently burned and dominated by Cistus species. Cork oak recruited better than the other oaks in medium and high shrublands dominated by Erica arborea. In contrast, recruitment was high for holm and downy oak in mixed oak stands and mixed pine-oak stands that have not burned for decades. Microsite conditions such as coverage by litter and shrubs influenced oak recruitment, whereas landscape configuration and stand basal area had no influence. Our results suggest that strategic shrub-clearing, oak planting and protection of mixed oak woodlands as seed sources would help maintaining oak populations in the woodland–shrubland mosaic.

Microwave Photonic Signal Processing

This paper reviews the recent advances in the field of radio frequency signal processing using photonic devices and subsystems or microwave photonic (MWP) signal processing. We focus our attention on the results reported during the last six years, as previous work has been adequately addressed in previous review papers. After a brief introduction to the basic concepts involved in MWP signal processing, we focus our attention on the most significant advances reported by different research groups in overcoming their main limitation factors. Recent advances in the emergent topic of integrated MWP signal processors are also covered and the novel approaches toward the evaluation of the main figures of merit are discussed. New proposed applications and future directions of work are also considered.

Inland Ports in the Republic of Croatia: Approvals for Port Activities instead of Concessions

According to the 1998 Act on Inland Ports, the right to performall port activities within inland ports of the Republic ofCroatia is given on the basis of concession, obtained throughbidding. It has been noticed in practice that modem businessprocesses and traffic flows are more dynamic than before whenclassic concession relations were created. Also, types andamounts of cargo are changing every couple of years, which isfollowed by quick adjustments, instead of working according torigid and long-term defined decisions and concession contracts.Furthermore, the practice has shown for some activitiesthat the number of port providers (such as ship suppliers,port-agency and freight forwarders) should not be limited. Thismeans that the system of a limited number of port providers isimportant only for the activities that require location within aport, as the port area is physically limited. Therefore, the newAct on Navigation and Inland Ports from 2007, whose framehas been completed by sub-law acts during 2008, has replacedthe complex concession system for performing activities in inlandports by a more liberal approval system. On the basis ofthese, higher dynamics of work of port providers is enabled aswell as easier adjustment to market conditions. Furthermore,the main limitation factor that determines the number of portusers becomes the available physical space within a port, whichprovides undisturbed competition, along with larger offer ofport services that do not require that space. It is also importantto point out that the new Act specifically includes distributionand cargo logistics, also processing and improvement of goodsas well as industrial activities including production that enablecomplete economic utilization of port capacities into the existingport activities, thus significantly changing the role of the portitself as a logistic centre.

Correlation between chlorophyll-a concentration and environmental factors in shallow lakes in plain river network areas of Suzhou

The correlation between chlorophyll-a concentration and some environmental factors (water temperature, pH, DO, CODMn, TN and TP) in sixty shallow lakes in plain river network areas of Suzhou was studied by regression statistical method, and the spatial and temporal distribution characteristics of chlorophyll-a were also analyzed. The results indicated that there were some differences in the spatial and temporal distribution of chlorophyll-a in shallow lakes. In winter, the average concentration of chlorophyll-a was lower than that in summer. The temporal distribution of chlorophyll-a in winter and summer also had some similar pattern decreasing from east to west. Significantly positive correlations were found between chlorophyll-a concentration and water temperature, pH, dissolved oxygen, permanganate indexes. Water temperature was possibly the main limited factor of phytoplankton growth. At the same time, significantly positive correlation was found between chlorophyll-a and nitrite nitrogen, but not for ammonia nitrogen, nitrate nitrogen, total nitrogen. However, positive logarithmic correlation was found between chlorophyll-a and total phosphorus, and negative logarithmic correlation was found between chlorophyll-a and the ratio of total nitrogen to total phosphorus. The results suggestted that phosphorus might be the limited factot in the shallow lakes to some extent.

Fretting Fatigue Phenomena on an all Aluminium Alloy Conductor

This paper concerns about a failure analysis of an electric all aluminum alloy conductor (AAAC) damaged and broken for fretting fatigue phenomena induced by aeolian vibrations. Life of electric conductors is often reduced by various degradation mechanisms such as repeated bending, fluctuating tension, distortion, fatigue, wear and corrosion phenomena. However the main limiting factor of the electrical conductors is related to aeolian vibrations in the high frequency range (between 5 to 50 Hz). Conductor oscillations may lead to fretting fatigue problems (otherwise called fretting wear) caused by wind excitation, mainly in the suspension clamp regions, spacers or other fittings. The induced aluminium wire fracture imply a drastic reduction in the transmission line service. Vibration dampers are considered the most effective method to extend service life of electric conductors, as they are the means to reduce fretting damage of aluminium wires. The aim of the present work is to investigate the failure of an AAAC conductor of a 400kV overhead transmission line (twin conductors) located in Touggourt Biskra (Algeria); the damaged and broken conductors were operated in-service only for six months without spacers or dampers. Three different types of conductors have been taken as experimental samples: the in-service broken conductor, another in-service damaged conductor and a new conductor from warehouse as terms of comparison. Samples have been analysed to identify the root cause of the failure and to verify the conformity of the conductor elements to the international standards. The investigation has outlined the morphology of the fretting damage: in all cases the fractured wires have shown typical static deformation marks and dynamic fretting wear tangential marks associated with intense presence of Al2O3 debris.

Unrelated Cord Blood Banking and Transplantation: Implications for Obstetricians

Cord blood is recognised as a rich source of haematopoietic stem and progenitor cells and its use has increased greatly in recent years. Since first cord blood transplantation was performed in Paris in 1988, knowledge of the biologic characteristics of umbilical cord blood has improved, and the benefits of using cord blood stem cells have become apparent. In fact, cord blood has showed to have several advantages as compared to bone marrow: easy availability, lower risk of infectious diseases transmission such as CMV and EBV and lower risk of graft versus host disease. However, cord blood units progenitors content is usually only sufficient for smaller recipients, usually children weighing less than 40 Kg. Gluckman et al showed grafting occurring in 85 percent of patients receiving 37 million or more nucleated cells per kilogram of body weight. In spite of this, use of cord blood in greater recipients is increasing and an effort to improve cord blood haematopoietic content is mandatory. In fact, the main limitation factor for the wide use of CB as a source of hematopoietic progenitor for transplantation is cell dose. Some of the specific areas identified by some studies for improvement of CB cell content are donor selection and CB collection. Implications of obstetricians in these issues are very important and necessary. We have evaluated cord blood donors selection criteria and two different modes of collection in order to optimise the cord blood banking proceedings and increase the quality of the CB units stored. We will review the results of our previous studies in these areas and the results of literature. Keywords: Umbilical cord blood (UCB), infectious disease, cryopreservation, hematopoietic cell, pregnancy, Multiple gestation, IVF, prematurity, morbidity, single embryo transfer, PGD, blastocyst, cleavage stage embryo, ovulation induction

Optimizing Umbilical Cord Blood Collection: Impact of Obstetric Factors Versus Quality of Cord Blood Units

Introduction The main limitation factor for wide use of umbilical cord blood units (UCBs) as a source of hematopoietic progenitors for transplantation is cell dose. International standard guidelines recommend 2 × 10 7/kg as the minimal nucleated cell dose for UCB transplantation for adults and 3.7 × 10 7/kg for children. Therefore it is important to the optimize donor selection and the collection method so as to achieve high cell doses. In this study our main purpose was to determine whether obstetric factors influence UCBs collected. Study design The study involved 304 UCBs collected from January to December 2004. The UCBs were collected after donor selection based on international criteria for cord blood banking. We analyzed UCB biological features such as collected volume, total nucleated cells (TNC), and CD34-positive cells, and obstetric factors. Results First, our study showed by multivariate analysis that infant weight was the main factor that influenced biologic features of UCB collected such as total volume ( P = .000), TNC ( P = .000), CD34 total count ( P = .003), and CFU-GM ( P = .004). Placental weight > 600 g produced a better volume ( P = .007) and increased TNC ( P = .056). Gestational age > 39 weeks enhanced CD34% ( P = .016). Regarding route of delivery, we found that cesarean section produced higher volume and reduced WBC count compared to vaginal delivery, regarding cord length, it increased TNC ( P = .037). And last, we noticed that female infants increased WBC ( P = .013) and CD34 + total count ( P = .019) more than male ones. Conclusions Our results confirm that volume and TNC are influenced by several obstetric factors, such as greater infant and placental weight, predicting a better collection.

Evaluation of soil nutrient status in poplar forest soil by soil nutrient systematic approach

A study was conducted to evaluate the soil nutrient status of poplar plantation by Soil Nutrient Systematic Approach (SNSA) in Jianghan Plain, Hubei Province, China. Soil physiochemical properties were analyzed in laboratory through collection soil samples of study site. Ten treatments of application different fertilizers were designed such as CK, optimum treatment (N, P, K, Zn), −N(P, K, Zn), −P(N, K, Zn), −K(N, P, Zn), +Mg(N, P, K, Zn, Mg), −Zn (N,P,K), +2P(N, 2P, K, Zn), +2K(N, P, 2K, Zn), and 2N+2P+2K(2N, 2P, 2K, Zn) for field experiment to test the effect on tree height, diameter (DBH) growth, and dry weight of poplar. The results showed that there was no significant difference in tree heights between treatments with different fertilizers, diameter growth of poplar trees in treatments of lack of N and Zn was significantly slower than that of trees in optimum treatment, and dry weight of poplar dropped significantly for treatment of CK as well as treatments without application N and Zn. It is concluded that N and Zn were main limiting factor for poplar growth. Results from laboratory analysis and field experiment were uniform perfectly, which proved that SNSA was reliable in evaluating soil nutrient status of poplar plantation.

Optimizing donor selection in a cord blood bank.

The main limitation factor for the wide use of umbilical cord blood (UCB) as a source of hematopoietic progenitor for transplantation is cell dose. One of the specific areas identified by some studies for improvement of UCB collection is donor selection. Over a 3-mth period, 391 consecutive maternal-neonatal pairs were evaluated during the pre-partum period in the maternity ward at La Fe University Hospital (Valencia) by the Cord Blood Bank staff. Reasons for discarding umbilical cord blood donors and collected UCB units at the Cord Blood Bank in Valencia have been analysed. Obstetric factors influencing TNC content of 1300 collected UCB units have been determined, in order to establish obstetric criteria for cord blood donors selection in our geographic area. Only 32.5% of potential cord blood donors were refused. Among 1300 UCB collected, 506 (38.9%) were discarded before cryopreservation, mainly due to low cell counts. Multivariate analyses showed that the main significant factors influencing nucleated cell count were the weight of the placenta, sex of newborn and mode of collection. Our study shows that maternal medical histories must be completely reviewed by medical staff before collection of the UCB. Obstetrical factors influence cell content of UCB and could be added to standard cord blood donor criteria in order to improve the bank efficiency.