bluuebunny/crossref_metadata_2025 huggingface dataset:
Hasil Belajar dan Aktivitas Siswa Setelah Diterapkan Pembelajaran Guided Inquiry Pada Materi Penerapan Listrik DC dan AC
Authors: Sugiarti Sugiarti
Published: January 2018

This study aims to determine the results of student learning after applied physics learning using guided inquiry model and student activities during the process of physics-based learning guided inquiry in high school on the material Application of AC and DC Power. Implementation of this learning using one group pretest-posttest design, the first step to make measurements as the initial test, then subject to treatment within a certain time, then performed the final test. After doing teaching and learning activities on the material application of DC electricity and AC classical completeness reached 91.7%. The average student learning outcomes after guided inquiry based learning activities increased from 34.2 to 85. The most frequent student activity in the guided inquiry learning phase was experimentation and listening to teacher's explanation of 14%.
A new species of Parapsilorhynchus Hora, 1921 (Teleostei, Cyprinidae) from Mahanadi River basin of Odisha, India
Authors: Baliarsingh B. K. , Kosygin Laishram
Published: January 2018

A new cyprinid fish, Parapsilorhynchus swaini sp. nov., is described based on specimens collected from a stream nearHarisankar, Mahanadi River basin of Odisha, India. It differs from other species of the genus in having following combinationof characters: elongated and slender body (depth at dorsal fin origin 16.9-18.7% SL); narrow and slender head (width60.0-68.7% HL, height at occiput 40.0-50.0% HL); narrow inter orbital space (46.6-50.0% HL); 33-34 lateral line scales; 3simple pectoral fin rays, poorly developed callous pad behind lower lip which is not delimited posteriorly, pectoral fin longerthan head length, presence of tubercles on snout and a black bar on the anal fin. With the description of this new species,distributional range of the genus Parapsilorhynchus is extended further north in the Eastern Ghats to the Mahanadi Riverdrainage of Odisha.
Changes in the diet of predatory ribbonfish Trichiurus lepturus Linnaeus, 1758 with increasing body size along Chennai coast
Authors: Gomathy S. , Vivekanandan E.
Published: January 2018

In recent years, it has been recognised that predatory fishes are rapidly declining in marine habitats. Hence, gathering information on biological characteristics such as dietary dynamics of predatory fishes has assumed importance. Considering this, the dietary dynamics of the predatory ribbonfish Trichiuruslepturusfrom Chennai coast was assessed by analysing the stomach condition and contents, with reference to body size. Representatives of the Order Clupeiformes (Index of relative importance, IRI 33.7%) comprising oilsardine, lesser sardines and anchovies were the major prey items of T. lepturus. Predation by T. lepturus was aided by morphological adaptations, such as dentition, hard and spinous gill rakers, short stomach, high body depth-total length ratio of 1: 17.1 and large mouth (gape area of 1534 mm2 in adult fish).With increasing body size, the capacity to predate upon relatively larger prey increased. The differences in diet composition between ribbonfish of small, medium and large size were well-represented byIRI, prey specific abundance and cluster analysis. The fish is a top predator (trophic level: 4.17) and a specialist feeder (niche breadth: 2.63). As specialist feeders have a narrow choice of food, they are more vulnerable to fishing. It is important that management of multispecies fisheries should focus more on the sensitive predatory species.
Length-weight relationship and certain biological aspects of the Indian white shrimp Fenneropenaeus indicus (H. Milne Edwards, 1837) exploited by trawls in the Arabian Sea off Kerala coast, India
Authors: Pillai S. Lakshmi , Radhakrishnan E. V. , Maheswarudu G. , Radhakrishnan M.
Published: January 2018

Length-weight relationship (LWR), sex ratio and maturity of Fenneropenaeus indicus (H. Milne Edwards, 1837), was analysed based on samplings from coastal trawl fishing grounds in the Arabian Sea off Kerala coast, India. The male tofemale ratio (1:1.27) did not vary significantly from the hypothetical 1:1 ratio. Length at maturity (Lm50) was estimated at 122 mm total length for females. The LWR did not differ significantly between male and female shrimps. The information generated from this study will enhance knowledge on the biology of the species and assist in assessment and management of its stock.
Reproductive biology and diet of the grey sharpnose shark Rhizoprionodon oligolinx Springer, 1964 (Chondrichthyes: Carcharhinidae) from the north-eastern Arabian Sea
Authors: Purushottama G. B. , . Thakurdas , Ramasubramanian V. , Dash Gnyanaranjan , Akhilesh K. V. , Ramkumar S. , Kizhakudan Shoba Joe , Singh V. V. , Zacharia P. U.
Published: January 2018

Information on reproductive biology is presented for the grey sharpnose shark Rhizoprionodon oligolinx Springer, 1964 (Chondrichthyes: Carcharhiniformes), collected off the north-west coast of India in the Arabian Sea. A total of 711 individuals, of 27.0 to 93.0 cm total length (TL), 180 to 2600 g total weight (TW) were used for the study. The lengthweight relationships were significantly different between the sexes. The size-at  maturity (Lm50) for females and males was estimated to be 62.3 and 59.5 cm TL respectively. Number of embryos ranged from 1 to 7 and the size at birth was estimated between 25 to 30 cm TL. Overall sex ratio favoured the females slightly at the rate of 1.27:1. There was significant positive correlation between maternal TL and number of embryos (p<0.001). Dietary analysis of stomach contents (%IRI) revealed that R. oligolinx feeds primarily on teleosts (95.5%), cephalopods (3.2%) and crustaceans (1.2%). This study presents the first detailed biological observation on size, sex composition, size-at-maturity (Lm50) and length-weight relationship of R. oligolinx from the northern Arabian Sea.
Isolation and characterisation of virulent Serratia marcescens associated with a disease outbreak in farmed ornamental fish, Poecilia reticulata in Kerala, India
Authors: Dharmaratnam Arathi , Kumar Raj , Basheer V. S. , Sood Neeraj , Swaminathan T. Raja , Jena J. K.
Published: January 2018

Pathogenic strain of Serratia marcescens (NPSM-1) with multiple drug resistance was isolated from guppy Poecilia reticulata with clinical signs of fin rot and was confirmed by biochemical tests and 16S rRNA gene sequencing. The extra cellular proteins (ECP) of the bacteria exhibited marked cytotoxic activity in vitro on Cyprinus carpio koi fin (CCKF) cell line. The in vivo challenge studies confirmed that the isolate was highly pathogenic to fish when the fishes were injected with1 x 104 CFU/fish and the same bacterium was re-isolated from infected fish, post-challenge. S. marcescens produced large zones of haemolysis on 10% sheep blood agar. The bacteria was found to carry virulence genes; extracellular metalloprotease gene (Pr596) and AHL synthase gene (SpnI). The bacterial isolate was tested to determine sensitivity against 16 antibiotics and was sensitive to only 5 viz., cefixime, chloramphenicol, ciprofloxacin, gentamycin and erythromycin. The study indicates that S. marcescens can cause disease in ornamental fish and the bacterium being a known human pathogen, may also cause infections in humans having direct contact with infected fishes. This is the first report describing S. marcescens as a pathogen of freshwater ornamental fish in India.
Assessment of chlorophyll-a and sea surface temperature variability around the Mascarene Plateau, Nazareth Bank (Mauritius) using satellite data
Authors: Ramchandur V. , Rughooputh Soonil D. D. V. , Boojawon R. , Motah B. A.
Published: January 2018

The Mascarene Plateau is characterised by shallow banks namely Saya de Malha and Nazareth which are known to harbour high phytoplankton biomass along the slope down to the ridge. Correlation between sea surface temperature (SST) and Chlorophyll-a (Chl-a) distribution surrounding the plateau was investigated. Higher Chl-a concentration was observed during the period July to September, indicating higher productivity due to upwelling. The regions east (61-630E) and west (57-590E) of the Mascarene Plateau were also studied along latitudes 130S up to 180S in the exclusive economic zone of Mauritius, where most of the fishing activities are concentrated. In general, 2008 was observed to be less warm during the past 14 years registering a drop with respect to the maximum monthly mean records, whilst 2006 was the most productive during winter season in the region of study. Chl-a bloom was observed after cyclone Imelda in April 2013 showing Chl-a concentration above 0.3 mg m-3 along latitude 130S and longitude 570E. The study reveals that the western side of the plateau is more productive with relatively warmer surface temperature compared to the eastern side of the plateau.
APAKAH METODE KASUS EFEKTIF SEBAGAI ALAT PEMBELAJARAN PERPAJAKAN?
Authors: Rahmawati Emi , Ervanto Adi Dermawan
Published: January 2018

Penelitian ini bertujuan untuk meneliti lebih lanjut terkait dengan penerapan metode pembelajaran aktif berbasis kasus dalam mata kuliah perpajakan dan persepsi mahasiswa setelah mengadopsi strategi pembelajaran berbasis kasus pada mata kuliah perpajakan. Pendekatan penelitian ini adalah kuantitatif yang mengeksplorasi tingkat pemahaman mahasiswa pada mata kuliah perpajakan. Terdapat dua kelompok yang diamati yaitu kelompok pengendali (kontrol) dan kelompok yang diberi treatment. Pembelajaran berbasis kasus untuk mata kuliah perpajakan diterapkan pada mahasiswa akuntansi di program studi akuntansi Fakultas Ekonomi Universitas Trunojoyo Madura semester Genap Tahun Ajaran 2016/2017. Sampel dalam penelitian ini diperoleh dengan metode convenience sampling. Kuesioner digunakan untuk menyelidiki sikap/persepsi mahasiswa/i terhadap pengalaman belajar mereka. Hasil penelitian menunjukkan bahwa strategi pembelajaran berbasis kasus pada mata kuliah perpajakan belum efektif dalam meningkatkan pemahaman mahasiswa dalam proses belajar mengajar. Namun persepsi mahasiswa/i terhadap strategu pembelajaran berbasis kasus pada mata kuliah perpajakan menunjukkan bahwa sebagian besar mahasiswa/i (di atas 84%) mempersepsikan bahwa strategi kasus memang meningkatkan pembelajaran dan tingkat penerimaan afektif dari kelas yang menerapkan metode kasus tinggi (diatas 73%).
Understanding Lost Circulation While Cementing: Field Study and Laboratory Research
Authors: Therond E.. , Taoutaou S.. , James S. G. , Way P. W. , Gomes P.. , Dondale A..
Published: January 2018

Lost circulation is a time-consuming and expensive challenge, costing the oil and gas industry billions of dollars each year in materials, nonproductive time, and minimized production (Catalin et al. 2003; Fidan et al. 2004; API 65-22010). To mitigate lost circulation during cementing operations, a better understanding of how wellbore-strengthening mechanisms apply to cement slurries is necessary. The ability to control cementing-fluid properties to strengthen the wellbore and minimize losses during cementing operations is imperative for achieving adequate zonal isolation.

A field analysis was performed to understand the start of lost circulation during different phases of drilling and primary cementing. Offshore wells from four different locations were studied: Gulf of Mexico (GOM), the UK, Angola, and Azerbaijan. In parallel, laboratory research was performed to understand the behavior of cement slurries in controlled lost-circulation scenarios using a block tester. Measurements of formation-breakdown pressure and fracture-propagation pressure were made with different cement-slurry compositions and compared with pressures obtained with drilling muds.

In an analysis of 40 well sections that reported losses before or during primary cementing operations, the rate and severity of lost circulation varied for the wells studied, but it was concluded that losses were commonly induced while running casing or during precement-job mud circulation, but rarely during cement placement.

The laboratory research confirmed the field observation: It would take much more pressure to open or reopen an existing fracture with cement slurry than with a synthetic-oil-based mud.

This paper will present findings from the field analysis and laboratory research. It will also discuss strategies to prepare the wellbore for preventing losses before the cementing operation and to optimize cement formulations if losses have been induced during drilling, casing running, or prejob mud circulation.
Simulated Canola Yield Responses to Climate Change and Adaptation in Canada
Authors: Qian Budong , Jing Qi , Bélanger Gilles , Shang Jiali , Huffman Ted , Liu Jiangui , Hoogenboom Gerrit
Published: January 2018

Core Ideas

Responses of canola to climate change in Canada were simulated using a crop model.

An overall negative impact of climate change on canola yield was simulated.

Yield reductions are due to the increased heat stress and/or water stress.

The effects of earlier seeding could be very limited as an adaptation measure.

Developing canola cultivars tolerant to heat and water stresses is an urgent need.

A projected future warmer climate implies significant impacts on canola (Brassica napus L.) production in Canada. We aimed to use a modeling approach to simulate climate change impacts on canola yield in Canada and to evaluate potential adaptation measures. The CSM‐CROPGRO‐Canola model was used to simulate the responses of canola to the projected climate change at Brandon on the Prairies, and West Nipissing and Normandin in eastern Canada. Future climate scenarios for the near (2041–2070) and distant (2071–2100) future under two representative concentration pathways (RCP4.5 and RCP8.5) were developed based on climate change simulations by a regional climate model CanRCM4. Seeding dates were estimated from air temperature, precipitation, and soil moisture to account for the potential of earlier seeding as an adaptation measure. Compared to the baseline climate, simulated seed yield reduction was 42, 21, and 24% in the near future and of 37, 27, and 23% in the distant future, under RCP4.5, respectively for Brandon, West Nipissing, and Normandin. A larger reduction was simulated under RCP8.5, especially in the distant future at Brandon and West Nipissing. The simulated seed yield reduction was associated with increases in heat and water stresses under rainfed conditions with current N fertilizer application rates. Coping with heat and water stresses is a big challenge for canola production in Canada under the projected climate change, especially on the Canadian Prairies.
Strengths and Limitations of Nitrogen Rate Recommendations for Corn and Opportunities for Improvement
Authors: Morris Thomas F. , Murrell T. Scott , Beegle Douglas B. , Camberato James J. , Ferguson Richard B. , Grove John , Ketterings Quirine , Kyveryga Peter M. , Laboski Carrie A.M. , McGrath Joshua M. , Meisinger John J. , Melkonian Jeff , Moebius‐Clune Bianca N. , Nafziger Emerson D. , Osmond Deanna , Sawyer John E. , Scharf Peter C. , Smith Walter , Spargo John T. , van Es Harold M. , Yang Haishun
Published: January 2018

Core Ideas

Nitrogen recommendations for individual corn fields are less accurate than desired.

Nitrogen recommendations need improvement for economic and environmental reasons.

A review of fundamental concepts will improve understanding about N recommendations.

Examination of N recommendation systems, tests, and models will improve recommendations.

Nitrogen fixation by the Haber–Bosch process has more than doubled the amount of fixed N on Earth, significantly influencing the global N cycle. Much of this fixed N is made into N fertilizer that is used to produce nearly half of the world's food. Too much of the N fertilizer pollutes air and water when it is lost from agroecosystems through volatilization, denitrification, leaching, and runoff. Most of the N fertilizer used in the United States is applied to corn (Zea maysL.), and the profitability and environmental footprint of corn production is directly tied to N fertilizer applications. Accurately predicting the amount of N needed by corn, however, has proven to be challenging because of the effects of rainfall, temperature, and interactions with soil properties on the N cycle. For this reason, improving N recommendations is critical for profitable corn production and for reducing N losses to the environment. The objectives of this paper were to review current methods for estimating N needs of corn by: (i) reviewing fundamental background information about how N recommendations are created; (ii) evaluating the performance, strengths, and limitations of systems and tools used for making N fertilizer recommendations; (iii) discussing how adaptive management principles and methods can improve recommendations; and (iv) providing a framework for improving N fertilizer rate recommendations.
Precision of Growth Estimates and Sufficient Sample Size: Can Solar Radiation Level Change These Factors?
Authors: Elli Elvis F. , Olivoto Tiago , Schmidt Denise , Caron Braulio O. , de Souza Velci Q.
Published: January 2018

Core Ideas

The precision of growth models in different sample sizes and solar radiation levels was investigated.

Reduced solar radiation levels and larger sample size has provided more accurate estimates.

A method to estimate the sufficient sample size in estimating parameters with lesser error is proposed.

An easy method for analyzing residual effects is discussed.

Solar radiation levels (SRL) in suboptimal or super‐optimal levels modify biomass accumulation. Moreover, sample size might modify the precision of growth estimators; however, little is known about the joint effects of these factors on the precision of growth estimators in nonlinear models. The aim of this study was to determine whether SRL and sample size could change the precision of the growth models. To this, three SRL (100, 70 and 50% of available solar radiation) were established in escarole (Cichorium endivia L. var. latifolia). In each SRL, the Schumacher's nonlinear model was fitted in 100 sample sizes to investigate if the increase in sample size and reduction of SRL could reduce the errors of estimates. Reduced SRL (70 and 50%) improved the precision of the model. The sufficient sample size for estimating growth parameters with lesser error increased when SLR was higher; however, 264 plants were sufficient to estimate growth parameters with best fits to this crop. We proved the increase in sample size jointly with the attenuation of solar radiation are effective methods to providing growth estimates with a lesser error. The method for estimating the sufficient sample size proposed here might be extended for several studies where nonlinear models are used to obtain growth estimates. By using these simple methods, both researchers and farmers might have a competitive advantage in planning their experiments or cropping systems, mainly in sites or seasons where light‐sensitive crops need to be cultivated.
Can Additional Inoculations Increase Soybean Nodulation and Grain Yield?
Authors: Moretti Luiz Gustavo , Lazarini Edson , Bossolani João William , Parente Tiago Lisboa , Caioni Sheila , Araujo Ricardo Silva , Hungria Mariangela
Published: January 2018

Core Ideas

A full set of N2–fixing nodules can supply soybean N demands.

Seed inoculation increased nodulation and grain yield of field‐grown soybean.

Additional spray inoculations (V1, V3, V6, R1, or R3) resulted in further increases.

New nodules and grain yield increases can be achieved by additional inoculations.

Highly productive soybean [Glycine max (L.) Merr.] genotypes require that large amounts of N be supplied throughout the growth cycle to attain high yields. The nutrient can be obtained through biological N2 fixation by elite bradyrhizobial strains if a set of fully functional nodules is available. This study was conducted during two crop seasons in the central‐west region of Brazil to investigate if additional inoculations via spray applications of bradyrhizobia at different stages of the growth cycle can result in increased nodulation and grain yield. Even though the soils had high populations of soybean bradyrhizobia, seed inoculation at sowing increased grain yield by 28 and 27% in the first and second seasons, respectively, compared to the non‐inoculated control. Additional inoculations performed until the R6 stage significantly increased soybean nodulation, which might indicate that plants were able to overcome the limitations of autoregulation of nodulation, allowing the development of new functional nodules to sustain the increased demand for N at latter stages of the growth cycle, especially during pod filling. In response to the increased nodulation, grain yield gains of 2 and 7% were obtained in the first and second experiments, respectively, relative to inoculation at sowing only. Our results indicate that soybean roots can form new nodules in response to additional inoculations, promoting increased N2 fixation and higher grain yield.
Physical Traits Related to Rice Lodging Resistance under Different Simplified‐Cultivation Methods
Authors: Liu Qihua , Ma Jiaqing , Zhao Qinglei , Zhou Xuebiao
Published: January 2018

Core Ideas

Rice lodging resistance under three simplified‐cultivation methods was in order of mechanical transplantation > dry direct sowing > wet direct sowing.

The reduction in lodging resistance was primarily attributed to increased internode length, decreased internode width, cull wall thickness, dry weight per centimeter, breaking stress, and bending moment of the third and fourth internodes from the top.

Lodging has been a limiting factor for the achievement of high grain yield and quality in rice (Oryza sativa L.) production. It is necessary to evaluate rice lodging resistance under simplified‐cultivation methods widely adopted in China. With this objective, we investigated rice lodging resistance under mechanical transplantation (MT), dry direct‐sowing (DDS), and wet direct‐sowing (WDS) methods by measuring physical traits of stems. Our results show that, among the three cultivation methods, rice lodging resistance under MT was the strongest while it was the weakest under WDS. The average breaking stress of the two bottom internodes (N3 and N4) under MT was 27.11 and 54.65% higher than under DDS and WDS. However, the average lodging index of the two bottom internodes was decreased by 16.08 and 24.69% under MT compared to that under DDS and WDS. These significant differences in lodging resistance were attributed primarily to the changes in physical parameters (i.e., the internode length, internode width, culm wall thickness, dry weight per centimeter of culm and bending moment) of the third and fourth internodes from the top. The rice yield under WDS only reached 5.08Mg ha−1, which was 45.68 and 36.89% lower than that under MT and DDS. The results suggest that this severe damage to grain yield was due to lodging occurrence. Therefore, it is urgent to apply agronomic management practices to mitigate sustainably the risk of lodging in rice production, particularly for direct‐seeded rice.
Maize Yield Potential and Density Tolerance
Authors: Gonzalez V. H. , Tollenaar M. , Bowman A. , Good B. , Lee E. A.
Published: January 2018

Maize (Zea mays L.) yield potential has not undergone genetic improvement during the hybrid era, yet substantial genetic improvement has occurred for tolerance to high plant population densities. As many crops including maize are approaching yield plateaus, it may be necessary to exploit other means of increasing grain yields. In this study, we examine potential reasons for why this occurred. Using a four‐way breeding cross representing the commercial germplasm pool, we demonstrate that the lack of genetic improvement in yield potential is not due to the two attributes being antagonistic. We then demonstrate that the lack of genetic improvement in yield potential is not due to density‐tolerant genotypes being higher yielding at modern conventional plant densities. We show that physiological differences in partitioning dry matter to the grain (i.e., harvest index [HI]) are present in a set of genotypes with contrasting yield potential and density tolerance genotypes. However, a higher or a lower HI is not associated with yield potential either. Finally, we show that the density‐tolerant genotypes exhibit a static kernel set efficiency (KSE), meaning that regardless of the plant growth rate at silking (pGRS), the number of kernels formed per unit dry matter fixed is constant. Surprisingly, the hybrids with high yield potential possess a dynamic KSE and are capable of sustaining kernel set at higher levels when pGRS is low. Given our findings, there is no apparent biological or genetic explanation for genetic improvement in only density tolerance during the hybrid era.
Can Cover or Forage Crops Replace Fallow in the Semiarid Central Great Plains?
Authors: Holman Johnathon D. , Arnet Kevin , Dille Johanna , Maxwell Scott , Obour Augustine , Roberts Tom , Roozeboom Kraig , Schlegel Alan
Published: January 2018

Growing a crop in place of fallow may improve soil properties but result in reduced soil water and crop yields in semiarid regions. This study assessed the effect of replacing fallow in no‐till winter wheat (Triticum aestivum L.)–fallow with cover, forage, or grain crops on plant available water (PAW), wheat yield, grain quality, and profitability over 5 yr, from 2007 to 2012. Plant available water at wheat planting was reduced the most when the fallow period was the shortest (i.e., following grain crops) or when biomass production was the greatest. Winter and spring lentil (Lens culinaris Medik.) produced the least biomass, used the least soil water, and had the least negative effect on yield. For every 125 kg ha−1 of cover or forage biomass grown, PAW was reduced by 1 mm, and for every millimeter of PAW, wheat yield was increased by 5.5 kg ha−1. There was no difference in wheat yield whether the preceding crop was harvested for forage or left as standing cover. In years with above‐average precipitation, wheat yield was reduced 0 to 34% by growing a crop in place of fallow. However, in years with below‐average precipitation, wheat yield was reduced 40 to 70% without fallow. There was minimal negative impact on wheat yield growing a cover or forage crop in place of fallow if wheat yield potential was 3500 kg ha−1 or greater. Net returns were reduced 50 to 100% by growing a cover crop. However, net returns were increased 26 to 240% by growing a forage crop. Integrating annual forages into the fallow period in semiarid regions has the greatest potential for adoption.
Establishment and Function of Cover Crops Interseeded into Corn
Authors: Noland Reagan L. , Wells M. Scott , Sheaffer Craig C. , Baker John M. , Martinson Krishona L. , Coulter Jeffrey A.
Published: January 2018

Cover crops can provide ecological services and improve the resilience of annual cropping systems; however, cover crop use is low in corn (Zea maysL.)–soybean [Glycine max(L.) Merr.] rotations in the upper Midwest due to challenges with establishment. Our objective was to compare three planting methods to establish cover crops (winter rye [Secale cerealeL. ‘Rymin’], red clover [Trifolium pretenseL. ‘Medium’], hairy vetch [Vicia villosaRoth], field pennycress [Thlaspi arvenseL. ‘MN‐106’], and a mixture of oat [Avena sativaL.], pea [Pisum sativumL.], and tillage radish [Raphanus sativusL.]) (MIX) in corn at the seven‐leaf collar stage. Planting methods included directed broadcast into the inter‐row (DBC), directed broadcast with light incorporation (DBC+INC), and a high‐clearance drill (DRILL). The DRILL method achieved greater fall biomass than DBC for all species except pennycress, and DRILL and DBC+INC increased red clover and hairy vetch spring biomass compared with DBC. Cover crops did not affect corn grain or silage yield and reduced yield of the subsequent soybean crop by 0.4 Mg ha−1(10%) only when poor termination of hairy vetch occurred at one site. Cover crops with >390 kg ha−1of spring biomass reduced soil nitrate‐N compared with the no‐cover control. These results support that cover crops can be interseeded into corn at the seven‐leaf collar stage in the upper Midwest to reduce soil nitrate‐N while maintaining corn and subsequent soybean yields; however, effective cover crop termination is critical to avoid competition with the subsequent soybean crop.
Temporal Changes of Soil Water Retention Behavior as Affected by Wetting and Drying Following Tillage
Authors: Zhang Meng , Lu Yili , Heitman Joshua , Horton Robert , Ren Tusheng
Published: January 2018

Soil structure‐dependent properties are subject to changes with time and depth under the influences of agronomic practices and environmental factors. Wetting and drying (W/D) cycles following tillage alter the structure and pore‐related functions of field soils. This study investigates the effects of W/D cycles on temporal changes of soil porosity and water retention curves (SWRCs) of a tilled layer (0‐ to 15‐cm) during a post‐tillage period. Soil volumetric water content (θ) and matric potential (ψm) dynamics at three depths were monitored continuously, and the total porosity (Pt) was determined gravimetrically. Nine W/D cycles were identified in the experimental period. Soil Pt decreased gradually with time and depth and became relatively stable after four W/D cycles, and the SWRCs shifted toward higher θ values at a specific ψm. The magnitude of SWRC change was relatively small during the first to third W/D cycles when the degrees of saturation were relatively low, reached the maximum after the fourth W/D cycle during which the soil was nearly saturated, and became less significant thereafter. Soil water holding capacity was improved during the W/D processes mainly due to the reduction of effective porosity and development of residual porosity. During the earlier four W/D cycles, a higher initial θ also contributed to the increase of the residual porosity, and thus enhanced the soil water holding capacity. The difference, however, tended to disappear in later W/D cycles. The data show clearly that the θ–ψm relationships following tillage are dynamic.
Carbon Sequestration Potential Promoted by Oxalate Extractable Iron Oxides through Organic Fertilization
Authors: Huang Xiaolei , Feng Chenglong , Zhao Guanglei , Ding Mi , Kang Wenjing , Yu Guanghui , Ran Wei , Shen Qirong
Published: January 2018

Core Ideas

Organic fertilization increased the oxalate extractable iron oxides.

Oxalate extractable iron oxides contributed to soil organic carbon sequestration.

Soil organic carbon from 20 to 40 cm was more labile than that from 0 to 20 cm.

Oxalate extractable iron oxides preferentially preserved aromatic compounds.

Carbon sequestration in paddy soils through organic fertilization is of great importance for soil quality improvement in subtropical Asia. This study explored the effect of oxalate extractable iron oxides (Feo) on soil organic carbon (SOC) sequestration in response to different fertilization treatments. Soil samples were collected from 0‐ to 10‐cm, 10‐ to 20‐cm, and 20‐ to 40‐cm depth intervals in June 2016 after a wheat (Triticum aestivum L.) harvest. This study involved five treatments: control with no fertilizer (CK), chemical fertilizer (NPK), 50% chemical fertilizer plus manure (NPKM), 100% chemical fertilizer plus straw (NPKS), and 30% chemical fertilizer plus manure organic‐inorganic compound fertilizer (NPKMOI). Organic fertilization significantly (P < 0.05) increased the SOC content and the Feo concentration compared with chemical fertilization alone. The specific C mineralization rate (SCMR, rate per unit SOC) increased with increasing soil depths, suggesting that SOC at the 20‐ to 40‐cm depth was more labile than that from 0 to 20 cm. The percentage of SOC present as microbial biomass carbon (MBC) was significantly (P < 0.001) positively correlated with SCMR, indicating that soil microorganisms influenced the potential SOC mineralization. Furthermore, the alternation of drying and wetting in paddy soils drives the biogeochemical cycles of iron and SOC, during which organic fertilization promotes the accumulation of Feo possibly by forming organo‐iron complexes as indicated by the higher Feo content in NPKM than in NPK. The Feo was significantly (P < 0.001) positively correlated with SOC and the percentage of aromatic C, indicating that Feo may play an important role in preserving SOC, especially the aromatic compounds. Therefore, the enhancement of Feo by organic fertilization, especially organic manure that is enriched in aromatic compounds, improved the SOC sequestration potential in the rice (Oryza sativa)–wheat rotation system.
Carbon Sink Strength of Subsurface Horizons in Brazilian Oxisols
Authors: Souza Ivan F. , Almeida Luis F. J. , Jesus Guilherme L. , Pett-Ridge Jennifer , Nico Peter S. , Kleber Markus , Silva Ivo R.
Published: January 2018

Core Ideas

Mineralogy cannot explain the formation of MOAs in topsoil.

SRO and crystalline Al‐/Fe‐(hydr)oxides are both effective in the formation of MOAs in subsoil.

The initial amount of C associated to Al‐/Fe‐(hydr)oxides seems to affect the formation of MOAs.

Redistribution of plant litter towards the subsoil can enhance C storage in Oxisols.

Interactions with pedogenic oxides are a known mechanism of soil organic matter (SOM) protection, but little is known about how the protective power of pedogenic oxides varies with soil depth in highly weathered tropical soils. To address this issue, we followed the decomposition of a double‐labeled plant litter (13C/15N) in microcosm experiments using samples collected at four depths (0–10, 10–20, 20–40, and 60–100 cm) from six Brazilian Oxisols. These soils were selected to include a range of taxonomic subtypes, spanning wide variations in mineralogy and texture. After a 12‐mo incubation, we quantified the proportion of isotopically‐labeled SOM (13C/15N) within the mineral fraction <53 µm (i.e., clay+silt). We found that litter‐C retention increased with depth, while the opposite occurred for litter‐N. Correlations between isotopically‐labeled SOM and short‐range order (SRO) Al‐/Fe‐(hydr)oxides were insignificant in topsoil (0–10 cm), but increased with depth, reaching peak significance in the 20‐ to 40‐cm interval (r = 0.64 and 0.58, for litter‐C and ‐N, respectively). A similar trend was observed for crystalline Al‐/Fe‐(hydr)oxides, which were more strongly correlated with the retention of 13C than 15N. We posit that in subsoil, both SRO and crystalline Al‐/Fe‐(hydr)oxides are more readily involved in the neoformation of mineral‐organic associations. Overall, litter‐C is less efficiently transferred into the clay+silt fraction of C‐rich topsoil relative to C‐depleted subsoil horizons, which may represent a significant C sink for Oxisols.
Soil Property and Fertilizer Additive Effects on Ammonia Volatilization from Urea
Authors: Sunderlage Brent , Cook Rachel L.
Published: January 2018

Core Ideas

Total exchange capacity was the best soil predictor of volatilization from urea.

Urease activity and pH were not effective predictors of volatilization from urea.

NBPT effectively reduces ammonia volatilization compared with nonamended urea.

NBPT efficacy was reduced in more acidic soils.

Calcium salt of maleic‐itaconic copolymer did not reduce ammonia volatilization.

Urea efficiency can be substantially reduced through nitrogen loss as ammonia (NH3–N), which is controlled by soil properties and environmental conditions. A laboratory incubation measured the effects of a range of soil properties on ammonia volatilization over 7 d from 168 kg N ha–1as surface‐applied urea and the efficacy of two fertilizer additives: urea plus a commercial formulation of N‐(n‐butyl) thiophosphoric triamide (NBPT) + N‐(n‐propyl) thiophosphoric triamide (NPPT) (urea + NBPT/NPPT) and urea plus a commercial formulation of calcium salt of maleic‐itaconic copolymer (MIP) from 79 soils across the United States. Total exchange capacity (TEC), 0.01 mol L–1CaCl2pH (pH), soil organic matter (SOM), hydroxide buffering capacity (OHBC), clay content, and urease activity were measured as predictors. Generalized regression models identified that TEC, clay content, OHBC, and SOM accounted for most variation in NH3–N losses in urea (R2= 0.69) and urea + MIP (R2= 0.67). Total exchange capacity was the strongest predictor of volatilization; greater TEC resulted in lower NH3–N losses. pH and TEC accounted for the most variation in NH3–N loss among soils fertilized with urea + NBPT/NPPT (R2= 0.58). Volatilization increased with lower pH in urea + NBPT/NPPT, indicating that NBPT efficacy decreases in acidic soils, potentially due to faster chemical degradation. The addition of NBPT/NPPT to urea significantly reduced volatilization from 24.5 to 6.3% of applied N (P< 0.0001), whereas urea + MIP did not reduce volatilization (P= 0.9707).
Physicochemical and Structural Properties of an Oxisol under the Addition of Straw and Lime
Authors: Nunes Márcio R. , Vaz Carlos M. P. , Denardin José E. , van Es Harold M. , Libardi Paulo L. , da Silva Alvaro P.
Published: January 2018

Core Ideas

Liming represents a common agricultural practice for abating soil acidity.

High doses of lime on the Oxisol surface increases the electronegativity of the soil system.

High electronegativity increases clay dispersion in the uppermost soil layer.

Clay migration led to a series of physical alterations in soil subsurface layers.

Overliming can lead to the degradation of highly weathered soil structures.

Liming represents a common agricultural practice for abating soil acidity. Nevertheless, elevated amounts of agricultural lime in Oxisols, with or without cultural residue addition, could alter soil physicochemical properties and impact soil structure. In this context, the physical, chemical, and structural behaviors of an Oxisol under the addition of lime and straw were assessed. Lime doses (0, 3.9, 7.8, and 15.6 Mg ha–1) were either applied on the surface or incorporated into the 0‐ to 5‐cm soil layer. Straw applications followed the same procedure with quantities of 0, 4, 12, or 16 Mg ha–1. The effects on the soil profile were evaluated through physicochemical (specific surface area, ζ potential, and pH), physical (density, penetration resistance, water dispersible clay, and total porosity), and micromorphological properties (surface area, volume, connectivity, size, and pore anisotropy) 1 yr after soil incubation in polyvinyl chloride cylinders 30 cm long and 14.5 cm in diameter. Lime application on the surface or into the 0‐ to 5‐cm layer increased soil pH to values above 7.0 and the electronegative potential of soil colloid surface, promoting clay dispersion. Water‐dispersed clay migrated in the soil profile, causing pore obstruction, and higher soil density and penetration resistance. In addition, excessive lime decreased specific surface area, anisotropy degree and the connectivity of the soil pore system. Straw addition promoted a slight increase of colloids electronegative potential but did not alter soil physical properties.
Improving Nitrogen Fertilizer Use Efficiency in Surface‐ and Overhead Sprinkler‐Irrigated Cotton in the Desert Southwest
Authors: Bronson K. F. , Hunsaker D. J. , Mon J. , Andrade-Sanchez P. , White J. W. , Conley M. M. , Thorp K. R. , Bautista E. , Barnes E. M.
Published: January 2018

Core Ideas

Nitrogen use efficiency is low in surface‐irrigated cotton.

Canopy reflectance can guide in‐season N management.

Deep percolation of rain and irrigation is associated with nitrate leaching.

Nitrogen fertilizer use efficiency (NUE) is low in surface‐irrigated cotton (Gossypium hirsutum L.), especially when adding N to irrigation water. A NO3 soil‐test algorithm was compared with canopy reflectance‐based N management with surface‐ overhead sprinkler‐irrigation in central Arizona. The surface irrigation studies also compared fertigation of N fertilizer with knifing‐in of N and the addition of a urease and nitrification inhibitor (Agrotain Plus, Koch Agronomic Services, Wichita, KS) to urea ammonium nitrate (UAN). Cotton lint and seed yields responded positively to N fertilizer in all four site‐years. Recovery efficiency (RE) of N at low N fertilizer rates (60 to 76 kg N ha–1) ranged from 21 to 61% with surface irrigation and from 81 to 97% with overhead sprinkler irrigation. Deep percolation below 1.8 m was 4 to 11% of applied surface irrigations and rain, but was undetectable in the overhead sprinkler. Leaching of NO3 was apparently the largest N loss pathway in the surface‐irrigated system. Fertigating UAN into surface irrigation resulted in similar lint yields and RE as knifing UAN. Use of Agrotain Plus with UAN gave similar yields and RE as using UAN alone. Reflectance‐based N management using normalized difference vegetation index‐amber (NDVIA) saved 50% of N fertilizer of the full soil‐test based dose without a yield reduction in three of four site‐ years. Nitrogen fertilizer was over‐prescribed with the soil‐test‐based treatment. This may have been due to not accounting for N mineralization, which the reflectance method indirectly measures.
IMPLEMENTASI DISCOVERY LEARNING DENGAN BANTUAN PROGRAM CABRI 3D PADA MATERI POKOK DIMENSI TIGA KELAS X-A
Authors: Prasetyo Hadi
Published: January 2018

 Artikel ini membahas tentang penerapan model pembelajaran discovery learning  berbantuan program Cabri 3D untuk meningkatkan hasil belajar peserta didik materi pokok dimensi tiga. Penelitian ini dilatarbelakangi oleh hasil belajar peserta didik kelas X materi dimensi tiga tahun pelajaran 2013/ 2014 yang kurang dari KKM yaitu 75, dimana dari 54 peserta didik kelas X, hanya ada lima peserta didik yang tuntas, sedangkan rata-rata secara keseluruhan adalah 63,06 dengan persentase ketuntasan sebesar 9,26%. Hal ini disebabkan oleh peserta didik yang belum menguasai konsep-konsep dimensi tiga dan kesulitan dalam mengabstraksi model atau permasalahan pada dimensi tiga.

Penelitian ini bertujuan untuk menjawab rumusan masalah: apakah penerapan model pembelajaran discovery learning berbantuan program Cabri 3D dapat meningkatkan hasil belajar peserta didik materi pokok dimensi tiga kelas X-A MA Al Bidayah Candi Bandungan Tahun Pelajaran 2014/2015. keberhasilan penelitian ini ditunjukkan dengan adanya peningkatan hasil belajar di atas KKM yaitu 75 dan persentase ketuntasan peserta didik pada setiap siklusnya.

Penelitian ini termasuk penelitian tindakan kelas. Subjek penelitiannya adalah peserta didik kelas X-A MA Al Bidayah Candi Bandungan Kabupaten Semarang tahun pelajaran 2014/ 2015 sebanyak 20 peserta didik. Data dikumpulkan dengan metode dokumentasi, observasi, dan tes. Data yang terkumpul dianalisis menggunakan analisis deskriptif serta menentukan rata-rata hasil belajar dan persentase ketuntasan belajar.

Berdasarkan hasil penelitian, rata-rata hasil belajar dari siklus I ke siklus II meningkat dari 63,89 ke 83,13 atau sebesar 19,24 poin dan ketuntasan belajarnya meningkat dari 38,89% ke 80% atau sebesar 41,11%. Penerapan model pembelajaran discovery learning berbantuan program Cabri 3D dapat meningkatkan hasil belajar peserta didik. Namun tidak serta merta dapat meningkatkan hasil belajar, karena hal ini dapat dipengaruhi oleh berbagai faktor seperti pengelolaan kelas, kemampuan peserta didik, konsentrasi peserta didik, ketelitian, dan sebagainya. Sehingga disarankan kepada guru agar melakukan pembelajaran inovatif, bervariasi, dan memanfaatkan media dalam menunjang proses pembelajaran.
KONSEP PSIKOLOGI TRANSPERSONAL MENURUT ABU HAMID MUHAMMAD AL-GHAZALI
Authors: Muhaya Abdul
Published: January 2018

Psikologi transpersonal adalah salah satu madzhad dari psikologi yang mempelajari tentang potensi yang paling tinggi dari manusia; seperti  pengalaman trans yang dialami oleh manusia, penalaman spiritual, pengalaman mistik dan hal-hal yang berkaitan dengan kesadaran yang berada diatas ego (self beyond ego). Menurut Imam al-Ghazali, kondisi trans dapat terjadi karena pada dasarnya kesadaran itu tergantung pada tingkatakan ruh yang menerima persepsi. Perbedaan tingkatan ruh yang menjadi tempat terjadinya kesadaran menjadikan seseorang dapat memiliki perpindahan kesadaran mulai dari kesadaran yang bersifat indrawi, imaginatif, rasional, fikri dan qudsi. Bagi al-Ghazali manusia punya kemampuan untuk melintas dari kesadaran yang rasional (kesadaran yang diperoleh oleh akal) kedalam kesandaran yang lebih tinggi lagi: yaitu kesadaran yang terjadi pada diri diluar ego rasional (self- beyond Ego). Kesadaran tersebut disebabkan manusia memiliki kemampuan menjelajah wilayah diluar akal (Thur wara’ al-Aql). Pada kondisi ini, manusia mampu mengetahui objek yang semula tidak mampu diketahui oleh akal. Bagi al-Ghazali, penjelajahan self-beyond ego dapat dilakukan dengan mempertajam dzauq
A Clean, Mild, and Efficient Preparation of Aryl 14H-benzo[a,j]xanthene leuco-dye Derivatives Via Nanocatalytic MCM-41-SO3H Under Ultrasonic Irradiation in Aqueous Media
Authors: Fathollahi Mostafa , Rostamizadeh Shahnaz , Amani Ali M.
Published: January 2018

Aim and Objective:

The present study has developed an efficient and eco-friendly
protocol for the synthesis of aryl-14-H-dibenzo[a,j] xanthenes through a one-pot condensation
reaction of 2-naphthol and arylaldehydes in aqueous media using the nanocatalytic MCM-41-SO3H
under ultrasonic illumination.

Material and Methods:

Using SEM and XRD analyses, MCM-41-SO3H nanoparticles were
characterized. Therefore, for high magnification, taking the SEM image, the mesoporous surface of
MCM-41-SO3H nanoparticles coated with gold for 2 minutes was characterized. Moreover, at a scan
rate of 0.02° (2Θ)/sec, XRD analysis from 1.5° (2Θ) to 10.0° (2Θ) was performed.

Result:

For our considered sample, some well-ordered XRD patterns with one main peak as well as
three minor peaks equal to those of MCM-41 materials were observed.

Conclusion:

The suggested route demonstrates very promising properties like higher yields,
decrease in the time of reaction (5-10 min), mild and straightforward conditions, low level of
toxicity, and inclusion of a cost-efficient and ecofriendly catalyst having considerable reusability.
Potential Application of Centrifuges to Protect the CNS in Space and on Earth
Authors: Hashimoto Makoto , Ho Gilbert , Shimizu Yuka , Sugama Shuei , Takenouchi Takato , Waragai Masaaki , Wei Jianshe , Takamatsu Yoshiki
Published: January 2018

Objective: Centrifuges are the principal means of generating physiological hypergravity and
have been used for many medical purposes, including the therapy of psychiatric diseases and evaluation
of vestibular system in the pilots. In particular, modern centrifuges have evolved into mechanically
sophisticated precision instruments compared to primitive ones in old times, indicating that centrifuges
might possess great potential in modern medicine. Indeed, studies are in progress to apply centrifuges
to musculoskeletal degenerative diseases, such as osteoporosis and sarcopenia. Given that the agingrelated
diseases are manifested under microgravity conditions, including astronauts and the bed-ridden
elderly, it is reasonable to speculate that centrifuge-induced hypergravity may counteract the progression
of these diseases. Such a view may also be important for neurodegenerative diseases for which the
radical treatments are yet to be established. Therefore, the main objective of this paper is to discuss a
potential therapeutic use of centrifuges for protection against the central nervous system (CNS) disorders,
both in space and on Earth. Mechanistically hypergravity may exert stimulatory effects on preconditioning,
chaperone expression, synapse plasticity, and growth and differentiation in the nervous
system. Furthermore, hypergravity may suppress the progress of type II diabetes mellitus (T2DM),
leading to inhibition of T2DM–triggered CNS disorders, including neurodegenerative diseases, ischemia
and depression.

Conclusion:

Moreover, it is possible that hypergravity may counteract the neurodegeneration in hippocampus
induced by the microgravity conditions and psychiatric diseases. Collectively, further investigations
are warranted to demonstrate that centrifuge-induced hypergravity may be beneficial for the
therapy of the CNS disorders.