Major Physicochemical Characteristics Research Articles

Groundwater Quality Assessment Based on a Statistical Approach in Gaya District, Bihar

India is one of the countries that face the serious problem of groundwater contamination. The current study's main objective is to evaluate the quality of the groundwater in the Serghati and its surrounding region of the Gaya district and its suitability for drinking purposes. To achieve this aim, 75 groundwater samples from the 15 sampling sites were collected during the period from March to May 2022. We measured and analyzed the major physicochemical characteristics of the water and compared them to the World Health Organization (WHO) standards. With the help of the Water Quality Index (WQI), groundwater quality was assessed. According to the study results, 3 sites have a WQI value of more than 100, which is unsuitable for drinking. Correlation matrices were used to assess groundwater quality and the extent of the interdependencies of the various parameters. Principal Component Analysis (PCA) reduces the number of significant variables. Three principal components with a total variance of 73.53% were identified and used in the analysis. Overall, the result indicates that most areas' water quality is good and safe for drinking.

Monitoring and evaluation of groundwater quality and its mapping using GIS over Belagavi city, Karnataka, India

Groundwater is a critical resource in the region for household, agricultural, and industrial reasons. However, the increasing population and rapid urbanization have led to potential pollution of groundwater sources. The objectives of the study are to ascertain the current groundwater quality, identify potential pollution sources, and develop a comprehensive GIS-based mapping system for effective management and decision-making. Water samples from several locations throughout the city were collected and examined for major physicochemical characteristics and pollutants. GIS was utilized to integrate and visualize the collected data, allowing for spatial analysis and mapping of groundwater quality. The mapping system will provide useful understandings into the distribution of water quality parameters, pollution hotspots, and potential risks to groundwater resources. The findings of this study will help to understand the state of groundwater quality in Belagavi. and provide a valuable tool for policymakers, urban planners, and water resource managers to implement targeted interventions for groundwater protection and sustainable management. Additionally, the GIS-based mapping system can be used as a framework for ongoing monitoring and evaluation, enabling timely detection of changes in groundwater quality and facilitating informed decision-making processes.

Groundwater Quality Assessment Based on Water Quality Index in Northern Cyprus

The largest coastal aquifer in northwestern Cyprus is the Morphou aquifer. The objective of the current study was to evaluate the quality of the groundwater and its suitability for drinking purposes in the Morphou (Güzelyurt) region, Cyprus. To realize this aim, 118 groundwater samples were collected during wet and dry seasons over a period of 11 years. Major physicochemical characteristics (electrical conductivity, pH, bicarbonate, calcium, magnesium, chloride, and total and carbonate hardness) were measured and analyzed. The assessment of groundwater quality was evaluated with the help of the Water Quality Index (WQI). The results demonstrated that 56% and 50% of the groundwater samples during dry and wet seasons respectively were unsatisfactory according to the Cl- limits of the WHO standard. In addition, approximately 10% of the groundwater samples come under class 2 (good water), 30% of the samples come under class 3 (fairwater), 13% come under classes 4 and 5, and the rest under class 6 (unsuitable for drinking).

Regulation of Ion Channel Function by Gas Molecules.

Our understanding of the gaseous signaling molecules that play important roles in diverse physiological processes keeps expanding. These gas molecules, also called gasotransmitters, include NO, H2S, 1O2, CO, and CO2 and are generated within the cell through enzymatic pathways and photochemical reactions. These molecules are chemically unstable and directly react with amino acids such as cysteine, histidine, and so on. Compared to well-characterized reactive oxygen species (ROS), including H2O2, ONOO-, O2-, and OH·, the gasotransmitters are in general less polar and show higher solubility in hydrophobic environments like the lipid membrane. Correspondingly, accumulating evidence has begun to unveil the broad impacts of these gaseous molecules on the function of membrane proteins, including ion channels. This review summarizes the major physicochemical characteristics of representative gasotransmitters and their regulation of ion channel functions.

МоО2/С Composites: Synthesis, Properties, and Formation Mechanism

Abstract—МоO2/С composites comprising monoclinic molybdenum dioxide were manufactured by microwave-assisted hydrothermal treatment of aqueous solutions of peroxomolybdic acid with glucose followed by annealing of the precursor in an inert atmosphere at 500°С. The carbon content in the composites ranged from 8 to 24 wt %. The major physicochemical characteristics of the compounds prepared were determined by X-ray powder diffraction, thermogravimetry, IR and Raman spectroscopy, scanning and electron microscopy, and low-temperature nitrogen adsorption. The molar component ratio of the reaction mass, Мо : С6Н12О6 = 1 : (0.25–1.0), was found to be an essential factor that determined the composition, textural and thermal properties of МоО2/С composites, as well as their formation specifics. A formation mechanism of МоО2/С composites was suggested.

Spring water quality assessment using water quality index in villages of Barwari Bala, Duhok, Kurdistan Region, Iraq

Periodic quality assessment of drinking water sources is necessary to guarantee the quality and security of water supply to people. Accordingly, this study assessed the drinking water quality of spring water of some villages located in Barwari Bala region of Duhok Governorate, Kurdistan region, Iraq, using the water quality index (WQI). To realize this objective, 120 spring water samples were collected from ten villages during the dry and wet seasons in 2018 and were analyzed for major physicochemical characteristics, including: calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), chloride (Cl−), sulfate (SO42−), nitrate (NO3−), pH, total dissolved solids (TDS), turbidity, total hardness (TH) and total alkalinity (TA). The results for pH, turbidity, sodium, potassium, chloride, sulfate and nitrate showed that the water samples at all the sampled springs were suitable for drinking and within permissible limits based on given standards. However, TDS, TA, calcium and magnesium exceeded the permissible limits at some sites. It was also observed that, except for SO42−, at almost all the sites, the majority of parameters were significantly greater during the wet season compared to the dry season. With reference to all the parameters, the WQI values ranged from 10.76 to 18.13 during the dry season and from 17.10 to 20.45 during the wet season, indicating that all water samples are classified as having “excellent” water quality for drinking purposes. The calculation of WQI based on specific parameters, where values were close to or exceeded the maximum acceptable limits, showed that the water quality status of all water samples was “good” quality, except for sites S6 and S8, which were classified as “poor” quality and are not considered suitable for drinking purposes without treatment. Water from almost all the sampled spring sites can be considered as suitable for drinking purposes, although some parameters exceed permissible limits. Simple filtration treatment of the sampled spring water before use is desirable for ensuring good quality and security of the water supply to people of these areas.

Cr(VI)/Pb2+ are responsible for PM2.5-induced cytotoxicity in A549 cells while pulmonary surfactant alleviates such toxicity

The composition of PM2.5 is extremely complicated, making the causes of PM2.5-induced toxicity hard to understand. To identify the major toxic components of PM2.5 particles, we used reductionism approach, synthesized and investigated a model PM2.5 library containing 24 carbon nanoparticles with adsorbed pollutants including Cr(VI), Pb2+, As(III) and BaP either individually or in combinations. Our data showed that major physicochemical characteristics of model PM2.5 library members were similar to PM2.5 particles from Guangzhou city (PM2.5-GZ). Cytotoxicity of lung cells (A549) was increasing as the member of adsorbed pollutants at environment relevant concentrations. Using these model particles, we identified that co-existence of Cr(VI) and Pb2+ components contributed to the PM2.5-induced cytotoxicity in A549 cells. Besides, pulmonary surfactant reduced the PM2.5-induced cytotoxicity in A549 cells probably via enhancing cell autophagy. The findings from this study suggest that systematic investigation using model PM2.5 particle library helps identify key toxic pollutants in otherwise very complex PM2.5 particles and facilitate our understanding of the underlying biological mechanisms.

Synthetic polymer scaffolds for soft tissue engineering.

Tissue engineering (TE) and regenerative medicine are progressively developed areas due to many novel tissue replacements and implementation strategies. Increasing knowledge involving the fabrication of biomaterials with advanced physicochemical and biological characteristics, successful isolation and preparation of stem cells, incorporation of growth and differentiation factors, and biomimetic environments gives us a unique opportunity to develop various types of scaffolds for TE. The current strategies for soft tissue reconstitution or regeneration highlight the importance of novel regenerative therapies in cases of significant soft tissue loss and in cases of congenital defects, disease, trauma and ageing. Various types of biomaterials and scaffolds have been tested for soft tissue regeneration. The synthetic types of materials have gained great attention due to high versatility, tunability and easy functionalization for better biocompatibility. This article reviews the current materials that are usually the most used for the fabrication of scaffolds for soft TE; in addition, the types of scaffolds together with examples of their applications for the regenerative purposes of soft tissue, as well as their major physicochemical characteristics regarding the increased applicability of these materials in medicine, are reviewed.

Assessing the Hydrochemical Conditions of the Tartar River

The paper gives the results of hydrochemical studies of the Tartar R.—the largest river in Nagornyi Karabakh Republic (NKR). Water quality was assessed with respect to the ecological standards of the Republic of Armenia in terms of major physicochemical characteristics and the concentrations of seven heavy metals. Water quality in the upper reaches of the Tartar R. was referred to the fifth class (poor quality), which is due to the effect of the dumps of the Sotck Gold Deposit and the pollution by agricultural, livestock, and municipal wastewaters. In the lower reaches of the Tartar R., the processes of dilution and self-purification neutralize the adverse effect of pollution sources on water quality, resulting in the improvement of water quality to the class not lower than medium, which is enough for the normal functioning of aquatic ecosystems, fishery, and irrigation. Thus, the Sarang Reservoir, which regulates the Tartar R. runoff, receives good-quality water.

Chemical and Physical Characteristics in Uncultivated Soils with Different Lithology in Semiarid Mediterranean Clima

The aim of this study is to identify the chemical and physical characteristics in uncultivated soils derived from different parent materials under semiarid Mediterranean climatic conditions which favoured the formation of fragile soils. The current work is of great interest in the agriculture and environmental stakeholders for providing a “benchmark” of undisturbed soil quality regarding organic content and nutrients availability. Principal Component Analysis (PCA) was used as the primary tool to demonstrate the soil quality stage, regarding nutrient availability. The statistical analysis revealed that one of the major physicochemical characteristics such as cation exchange capacity (CEC) is controlled exclusively from mineralogy and not from organic matter. Mineralogy and bulk chemical analysis is directly related to soil parent material lithology. The availability of inorganic nutrients (macro- and micronutrients) is low and relatively identical to most of the soils. PCA shows the unusual correlation of K+with not only illite content but also the OM in soils. The development of soils which are already of low quality in respect of organic content and nutrients is evident in Crete in most of the 54 samples investigated.

English

The present study was conducted to compare the biological activities and soil parameters associated with leaf litter decomposition under natural forest conditions. Emphasis was given on the impact of decomposition of four leaf litter types of Cassia siamea, Shorea robusta, Acacia auriculiformis, and Dalbergia sissoo trees in enhancing nutrient enrichment and major physicochemical characteristics in afforested laterite wastelands. Comparison of nutrient status of forest soil in Cassia, Shorea, Acacia, and Dalbergia tree stands during winter, summer and rainy seasons indicated that the organic carbon content was high in Dalbergia and Cassia but low in Shorea and Acacia. Similarly, nitrate nitrogen content of soil was also more in Cassia closely followed by Dalbergia and very low in the soil of Acacia and Shorea stands. Available phosphorus content of soil was also high in the soil of Dalbergia and Cassia forests. Shorea stand had the lowest organic carbon content whereas Acacia stand had low concentrations of nitrate nitrogen and available phosphorus. C/N ratio and P/N ratio was highest in Acacia followed by Shorea, low values in the soil of Cassia and Dalbergia stands indicated fast rates of carbon utilization and nutrient release. A general comparison showed that the soil was acidic in nature in all the stands with pH ranging from 5.18 in Acacia to 6.83 in Dalbergia. Similarly, the electrical conductivity of soil was highest in Dalbergia followed by Cassia, and Acacia to reach lowest in Shorea. Electrical conductivity was recorded low during winter and high during summer season in all the tree sites.

Synthesis and characterization of silica microsphere and their application in removal of uranium and thorium from water

Uranium (U) and thorium (Th) are known to cause acute toxicological effects in human, and their compounds are potential occupational carcinogens. During this work, silica microspheres were used to decontaminate the traces of U and Th in different water sources originated from groundwater and lake water. Ultra-filtration technique was used to isolate the microsphere from the water samples. Silica microspheres were synthesized based on a polyvinylpyrrolidone involved emulsion polymerization and subsequent sol–gel process. The microspheres were characterized for their size by using dynamic light scattering, and presence of silicate structure is verified by recording their attenuated total reflectance-Fourier transform infrared spectrum. The surface morphologies of the prepared silica microspheres were studied by using scanning electron microscope. Water samples collected from the groundwater and lake water were spiked with U and Th in the concentration range of 100–1,000 ng mL−1. The results of batch sorption experiments suggest that silica microsphere is very effective at pH 3, and sorption is more than 99.9 %. Equilibrium sorption follows Langmuir isotherms and the maximum U, and Th uptake is 30 and 36 mg g−1, respectively. Major physicochemical characteristics of the water were monitored before and after the decontamination process. Experimental results show no significant variations in any of the measured parameters.

Profiling the Dielectric Constant at the Membrane-Peptide Interface using Ionizable EPR Probes

Polarity, electric potentials, and hydration are the major physico-chemical characteristics of lipid membranes that govern membrane-protein and protein-protein interactions as well as small molecules transport. Insertion of transmembrane proteins perturbs membrane structure altering local dielectric environment and hydration at the membrane-protein interface. The significance of distorting local membrane structure at the lipid-protein interface for modulating protein-protein interactions should not be overlooked. In this work we report on employing pH-sensitive ionizable EPR labels to profile a heterogeneous dielectric environment along the α-helix of a WALP peptide integrated in a lipid bilayer. Labels were attached to two cysteine residues positioned equidistant from the center of the peptide so that the primary sequence of each peptide is palindromic, thus insuring symmetric location of the labels with respect to the bilayer center. The change in protonation state of the nitroxide was directly observed by EPR. Q-band double electron-electron resonance (DEER) experiments were carried out to determine the distance between spin labels when imbedded in lipid bilayers to provide information about the label location. Thus, for the first time measurements of local electrostatics at peptide-bilayer interface were based on direct distance measurements rather than on assumptions on the probe location. Two pH sensitive spin labels, methanethiosulfonic acid S-(1-oxyl-2,2,3,5,5-pentamethyl-imidazolidin-4-ylmethyl) ester (IMTSL) and S-4-(4-(dimethylamino)-2-ethyl-5,5-dimethyl-1-oxyl-2,5-dihydro-1H-imidazol-2-yl) benzylmethanethiosulfonate (IKMTSL), with intrinsic pKa's differing by approximately 2 pH units were used to expand the pH range of the titration experiments. This provided the opportunity to vary the lipid composition in order to investigate effect of the surface charge on dielectric profile at peptide-membrane interface. Water penetration at the peptide-membrane interface was assessed by hyperfine sublevel correlation spectroscopy (HYSCORE) experiment in which the hyperfine coupling between the nitroxide and hydrogen/deuterium atom of water is measured. Supported by NSF-0843632 to TIS.

우리나라 재래종 벼 유전자원의 미질관련 특성

농촌진흥청 농업유전자원센터에 보존되고 있는 우리나라 재래종 벼 유전자원 중 선발된 394품종의 미질과 관련된 특성을 분석하고 상호관계에 대한 결과는 다음과 같다. 1. 단백질 함량은 5.2~9.9%까지 다양한 분포를 보였고, Mg함량은 12.7 mg에서 37.7 mg까지의 넓은 범위의 분포를 보였으며, K함량 또한 60.0 mg에서 125.9 mg 까지의 넓은 범위의 분포를 나타냈고, 차진정도의 지표로 사용되는 Mg/K 비율은 일품벼보다 높게 분포하였다. 2. 쌀의 차진정도를 결정하는 주된 인자이며 미질을 나타내는 척도의 하나인 아밀로스 함량은 현재 우리나라 밥쌀용 수도 장려품종들이 대체로 18~20% 수준에 있는데 비하여 재래종 유전자원에서 메벼의 범위가 12.4~28.9%였고 18~20% 범위에 있는 품종은 144품종이었다. 3. KOH에 의한 알카리붕괴도는 0.0~7.0까지 분포하였는데 일품벼의 6.4와 유사한 품종이 95품종이었다. 4. Toyo 식미계를 이용한 식미 검정에서 현재 양식미 품종으로 평가받고 있는 일품벼와 유사한 품종이 16품종이고, 우리나라 사람들이 양식미로 선호하는 호화온도가 낮고 Toyo 식미치가 높은 품종은 IT 173444번, 008530번, IT 006554번이 대표적 이었다. This study was conducted to make clustering analysis based on major physicochemical characteristics related to palatability of 394 Korean rice land-races. The items investigated were protein content, Mg content, K content, Mg/K ratio, Toyo-taste value, ADV (alkali digestion value) and amylose content. The range of the physicochemical characteristics such as amylose, protein, magnesium, potassium was from 12.4 to 28.9%, from 5.2 to 9.9%, from 12.7 to 37.7 mg and from 60.0 to 125.9 mg, respectively. In this experiment, the grain quality, properties significantly associated with the estimates of Toyo taste meter, were protein and amylose contents and hot viscosity. Also, at the expected taste as a cooking rice, using Toyo taste meter, a total 16 accessions were selected as good taste as "Ilpumbyeo". Also, IT173444, IT008530 and IT006554 were selected as remarkable sources for the cooking rice, in terms of gelatinated temperature and Toyo taste meter value.

Saliva composition in three selected groups with normal stimulated salivary flow rates, but yet major differences in caries experience and dental erosion

Objective. It was hypothesized that, by comparing matched subjects with major differences in these dental diseases, but yet normal saliva flow rates, it would be possible to obtain data on the effect of saliva composition on dental disease isolated from the effect of the flow rate. Thus, the aim of the study was to compare the major physicochemical characteristics of stimulated whole saliva in three groups of 85 subjects, each with normal saliva flow rates and at least 24 remaining teeth. Materials and methods. A group with very little dental disease (healthy), a group with dental erosion (erosion) and a group with very high caries experience (caries) were chosen. Furthermore, the aim was to determine whether differences among groups could also be found on an individual level. Results. Although it was not possible to retrieve three groups whose members were completely identical, the present study points in the direction that, on a group level, subjects with very little dental disease seemed to have a more favorable physicochemical saliva composition with respect to higher calcium, phosphate, bicarbonate, pH, degree of saturation with respect to hydroxyapatite and a lower critical pH (p < 0.05 or less). However, on an individual level the explanatory power for the saliva composition was only 10% for caries experience and only 11% for dental erosion (p < 0.001). Conclusion. The compositional analyses performed in this study on stimulated whole saliva, including major physicochemical characteristics of saliva, will most likely have little predictive value for future dental caries and erosion in single individuals.

110kg 대비 130kg에 도축된 비육돈의 성장효율, 도체 품질 특성 및 수익성

양돈에 있어서 도살체중은 가장 중요한 경제 요인 중의 하나이다. 본 연구는 성장효율과 도체 품질에 크게 영향을 미치지 않고 비육돈의 도살체중을 130kg으로 증가시킬 수 있을 지의 여부를 알아보기 위해 착수되었다. 경남 지역에서 비육돈으로 가장 널리 사용되고있는 정육형 (Yorkshire×Landrace)×Duroc(YLD) 3원 교잡종 암퇘지 160두와 거세돼지 160두를 생체중 90kg에 선발하여 2(성)×2(도살체중; 110 vs. 130kg) ‘factorial’ 실험설계 하에 16돈방에 배치하였다. 공시돈에게는 3,200kcal/kg의 가소화 에너지와 15.5%의 조단백질을 함유하는 공시사료를 무제한 급여하였고, 계획된 체중에 도달하였을 때 도축하여 부분육 수율과 배최장근의 이화학적 특성을 조사하였다. 일당증체량은 거세돼지가 암퇘지보다 높았으나(0.86 vs. 0.79kg; P<0.01) 110kg 대비 130kg 도살체중 구 사이에는 차이가 없었다(0.83 vs. 0.81kg; P>0.05). 등지방두께는 암퇘지와 거세돼지 공히 130kg 도살체중 구가 110kg 도살체중 구보다 높았다(암: 17.6 vs. 21.6mm, 거세: 20.8 vs. 25.1mm). 정육중 삼겹살 비율은 거세돼지가 암퇘지보다 높았고(21.2 vs. 20.5%) 130kg 도살체중 구(21.4%)가 110kg 도살체중 구(20.2%)보다 높았다. 배최장근의 색깔, 48󰠏시간 육즙삼출율, 24󰠏시간 pH, 조단백질 및 조지방 함량 등의 이화학적 특성은 두 성간 혹은 두 도살체중간 차이를 나타내지 않았다. 110kg 대비 130kg 출하돈의 한계수익은 두당 약 󰠏20,000원에 달하였는데, 이 같은 손실은 거의 전적으로 130kg 출하돈의 도체가 너무 커 A, B 도체 등급의 도체중 상한선을 초과했기 때문이다. 그러나 만일 도체중 상한선이 철폐된다는 조건으로 계산하면 130kg 출하돈당 20,000원 이상의 한계수익이 발생할 수 있을 것으로 추정되었다. 이상의 결과는 정육형 비육돈에서는 성장효율이나 육질에 크게 영향을 미치지 않고 도살체중을 130kg까지 증가시킬 수 있고, 따라서 체중이 큰 출하돈을 수용하기 위해서는 ‘좋은 등급’의 도체중 상한선을 증가시킬 필요가 있음을 시사한다. The slaughter weight (wt) is a most important economic factor in swine roduction. The present study was undertaken to determine if it is feasible to increase the slaughter wt of finishing pigs to 130kg without significantly affecting the growth efficiency and carcass quality. One hundred and sixty gilts and 160 barrows born from lean-type Yorkshire×Landrace (YL)-dam and Duroc (D)-sire lines, which are most widely used for terminal breeding for pork production in Gyeongsangnam-do, were randomly allocated into 16 pens under a 2 (sex)×2 (slaughter wt; 110 vs. 130kg) factorial arrangement of treatments. The animals were fed ad libitum a diet containing 3,200kcal DE/kg and 15.5% crude protein. After slaughter at the predetermined wt, yields of trimmed primal cuts and physicochemical characteristics of the longissimus dorsi muscle (LD) were measured or analyzed. Average daily gain was greater (P<0.01) in barrows than in gilts (0.86 vs. 0.79kg), but it was not different between the 110- and 130-kg slaughter wt groups (P>0.05). Backfat thickness was greater in the 130- vs. 110-kg group in both sexes (gilts: 21.6 vs. 17.6 mm, barrows: 25.1 vs. 20.8 mm). The yield percentage of belly was greater in barrows than in gilts (21.2 vs. 20.5%) and also in the 130-kg vs. 110-kg group (21.4 vs. 20.2%). Major physicochemical characteristics of LD including the color, percentage of 48-h drip loss, 24-h pH and percentages of crude protein and fat were not influenced by slaughter wt. Marginal profit of the 130-kg vs. 110-kg market pig was approximately 󰠏20,000 won/head, which resulted primarily from the heavy carcass weight of the former exceeding the upper limit of the A- or B-grade. However, if it had not been for the carcass weight limit of the current grading system, a 130-kg market pig would have had a potential marginal profit greater than 20,000 won. Results suggest that slaughter wt of lean-line finishing pigs can be increased to 130kg without significantly compromising the growth efficiency and carcass quality and accordingly, the upper weight limit of the ‘good-grade’ carcass needs to be increased or abolished to accommodate the larger market pigs.

Micromorphology and development of interfluve paleosols: a case study from the Cenomanian Dunvegan Formation, NE British Columbia, Canada

Research Article| March 01, 2002 Micromorphology and development of interfluve paleosols: a case study from the Cenomanian Dunvegan Formation, NE British Columbia, Canada P.J. McCarthy P.J. McCarthy Department of Geology and Geophysics and Geophysical Institute, University of Alaska, Fairbanks, AK 99775–5780, USA. Search for other works by this author on: GSW Google Scholar Bulletin of Canadian Petroleum Geology (2002) 50 (1): 158–177. https://doi.org/10.2113/50.1.158 Article history received: 18 May 2001 accepted: 15 Sep 2001 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation P.J. McCarthy; Micromorphology and development of interfluve paleosols: a case study from the Cenomanian Dunvegan Formation, NE British Columbia, Canada. Bulletin of Canadian Petroleum Geology 2002;; 50 (1): 158–177. doi: https://doi.org/10.2113/50.1.158 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyBulletin of Canadian Petroleum Geology Search Advanced Search Abstract An obvious use of paleopedology for sequence stratigraphic analysis lies in the demarcation of erosional discontinuities or major pauses in sedimentation that allow us to recognize and map stratigraphically important surfaces, both in outcrop and subsurface. Many interfluve surfaces may be apparent on the basis of sedimentology and regional stratigraphy alone; however, their appearance can change markedly across a study area, making correlation difficult. A pedosedimentary approach has been utilized to reconstruct the sequence of pedogenic and sedimentary events recorded by the development of stratigraphically significant interfluve surfaces. This was based upon sets of closely-spaced thin sections taken from interfluve sequence-bounding paleosols exposed at Beatton River canyon, British Columbia, Canada. Micromorphology, field morphologies, and major physicochemical characteristics of three interfluve paleosols reveals a complex sequence of soil development related both to normal floodplain sedimentation and to periods of prolonged stasis resulting from valley incision. Two main pedosedimentary stages, related to regional changes in rates of generation of accommodation, are recorded at each interfluve, although the resolution, processes, and resultant features vary in a manner reflecting local differences in hydrology, topography, initial parent material composition, and time. These processes have operated through various pedogenic development pathways to produce polygenetic paleosol profiles on these Cretaceous interfluves. The pedosedimentary approach followed in this case study provides a means of deciphering the development of interfluve paleosols based upon detailed microstratigraphic associations and depth functions of their pedogenic features, in conjunction with ancilliary geochemical, mineralogical, sedimentological, and stratigraphic evidence. Consequently, potential sequence boundaries, identified on the basis of regional stratigraphic patterns, can be determined with a high degree of confidence on the basis of intrinsic evidence derived from the record of ancient landscape processes preserved within the interfluve paleosols. This content is PDF only. Please click on the PDF icon to access. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Purification and physico-chemical properties of an endo-1,5-α- l-arabinanase (EC 3.2.1.99) isolated from an Aspergillus niger pectinase preparation

Using low and medium (FPLC) pressure column chromatographic separation methods, an endo-1,5-α- l-arabinanase (EC 3.2.1.99) was purified from an Aspergillus niger pectinase preparation. The purification procedure combined different anion exchange and hydrophobic interaction chromatographies followed by gel filtration, yielding a highly pure and specific enzyme. The isolated endo-1,5-α- l-arabinanase was most active on linear 1,5-α- l-arabinan (90·2 U/mg), whereas branched arabinans from sugar beets were degraded to a lesser extent (∼ 14 U/mg). No other significant carbohydrate degrading activities could be detected. The enzyme was shown to be electrophoretically pure after silver staining and its identity was confirmed through specific binding to an antiserum directed against endo-1,5-α- l-arabinanase. The major physico-chemical characteristics of the enzyme were the following: M r 42 500 (SDS-PAGE), M r 33 900 (MALDI-TOF-MS), pI ≤ 3·0, pH optimum 4·8, temperature optimum 55°C, pH stability 3·5–8·0, temperature stability ≤ 45°C, K m = 0·205 mg/ml, V max = 1·77 × 10 −4 μmol/min, E A = 12·20 kcal/mol; Zn 2+ and Hg 2+ showed potent inhibitory effects.