bluuebunny/crossref_metadata_2025 huggingface dataset:
Hypolipidemic effects of curcumin, cinnamon, vitamin C and simvastatin in domestic rabbits
Authors: Ayoub R. Aldalou
Published: May 2021

This study investigated the hypolipidemic effects of curcumin, cinnamon, vitamin C and simvastatin in male rabbits. The hypolipidemic effect of these materials were assessed by following the effects on body weight, the lipid profile and liver enzymes. The lipid profile includes total cholesterol (TC), triglyceride (TG), high density lipoprotein (HDL), low density lipoprotein (LDL). The liver activities enzymes include aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) in serum. Highly significant increases in lipid profile parameters of rabbit group were found in rabbits fed with high lipid diet only over the respective values in the control group. Liver function profile showed a significant increase in this group as compared to those in the control group. The groups treated with curcumin, cinnamon, vitamin C and simvastatin showed a variable significant decrease in lipid profile in this order: cinnamon > vitamin C > simvastatin > curcumin and in liver functions profile in this order: curcumin > simvastatin > vitamin C > cinnamon. Groups treated with these materials showed significant body loss as compared to untreated rabbits in this order: cinnamon > curcumin > vitamin C > simvastatin.
THE METHODS AND TOOLS USED BY MANAGERS IN THEIR STRATEGIC DECISION MAKING PROCESSES
Authors: AYGÜN Salih , SEZGİN Orhan
Published: May 2021

Businesses operating complex and highly business environment are faced with threats or opportunities while performing. The purpose of this research is revealing the difference between strategic management practices of businesses and the level of awareness of managers to these practices. Under this purpose, with strategic analysis, it was tried to determine level of implementation of strategic management practices and at what stage and how managers and employees play a role in these practices. In addition, it was investigated whether they made strategic planning, whether they found themselves strategic or to what extent they found strategic and, if any, the direction of their strategies. In this framework, the answers to the research questions "The effect of family control on institutionalization", "The relationship between Institutionalization and Strategic Planning Process" and "The Relationship between Institutionalization and Strategic Management Process" were investigated. For this study, questionnaire questions were sent electronically to 49 managers and 30 replies were received. From research three results were obtained. Institutionalization increases as the control of family decreases, scope of strategic management and strategic planning increases, institutionalization also increases and family's control over the business decreases, institutionalization increases, and as the level of institutionalization increases, annual return increases.
Pengaruh Status Kepegawaian Terhadap Kepuasan Kerja Dan Komitmen Organisasional
Authors: Julindrastuti Dijah , Karyadi Iman
Published: May 2021

Research with the title The Effect of Employment Status on Job Satisfaction and Organizational Commitment takes the object of non-educational employees at UWKS Surabaya where this research was conducted to see whether employees with contract employee status and employees with permanent employee status have differences in job satisfaction and organizational commitment and to see whether job satisfaction influences organizational commitment. The population in this study were all non-educational employees at Universitas Wijaya Kusuma Surabaya. Sampling in this study was carried out using the convenience sampling method. In this study, the researcher distributed questionnaires to 70 respondents, and 60 have returned. To test hypotheses 1 and 2 using the independent sample t-test and hypothesis 3 using multiple linear regression analysis. After testing, the results showed that the work decision between Contract employees with employees were still no different, likewise, for organizational commitment, there was also no difference, whereas, for the effect of job satisfaction on organizational commitment, the results showed that job satisfaction affected organizational commitment, where if job satisfaction increases, organizational commitment will also increase or it was said that between job satisfaction and organizational commitment had a positive effect.
ÇAĞDAŞ SERAMİK SANATINDA BİYOMORFİK EĞİLİMLER
Authors: YILDIRIM Burak
Published: May 2021

Tarih öncesi çağlardan beri devam eden seramik üretiminde ortalama 20. yüzyıldan itibaren çağdaş sanata yönelik yaklaşımlar başlamıştır. Başlangıçta birtakım dinsel seramikler, figüratif heykelcikler ve yeme-içme-saklama kapları üretilen seramik malzeme ile giderek artan şekilde estetik kaygı ve sanatsal gaye arayışında olan formlar/eserler üretilmeye başlanmıştır. Çağımızda sanatsal anlamda çoğunlukla; belli bir kavramı/düşünceyi ifade eden, doğada bulunan varlıkları içselleştirip/yorumlayarak aktaran ya da sadece sanatçının kendi duygularını/fikirlerini ortaya koyan pek çok türde özgün seramik eserler üretilmektedir. Biyomorfizm kavramı günümüzde pek çok sanat dalında olduğu gibi seramik sanatçıları için de önemli bir ilham kaynağı olmuş ve birçok çağdaş seramik sanatçısı tarafından biyomorfik formlar/eserler üretilmeye başlanmıştır. Genel anlamda doğadaki canlıları, daha çok bitki/hayvan biçimlerini anımsatan, özelliklede mikroskobik canlıların ve deniz canlılarının belli görünüm veya özelliklerinin, sanatçılar tarafından belirli kişisel yorumlamalar/katkılar da ilave edilerek vurgulandığı yapıtlar olarak tanımlanan biyomorfik eserler; görünümlerindeki nadir rastlanan tarzdaki estetik detayların yoğunluğu bakımından çağımızda oldukça dikkat çekici/değerli bulunmaktadır. Günümüz çağdaş seramik sanatında, dünyanın çeşitli bölgelerinden pek çok sanatçının eserlerinde biyomorfik eğilimlere rastlamak mümkündür. Bu çalışmada; biyomorfizm kavramı, biyomorfik sanat ve günümüz çağdaş seramik sanatında biyomorfik eğilimler konuları irdelenmiş, biyomorfik seramik eserler üreten bazı çağdaş sanatçıların örnek niteliğinde olduğu düşünülen eserlerinin tanıtımına yer verilmiştir.
Học chiến lược từ doanh nghiệp siêu nhỏ- Tại sao không
Authors: Giao Ha Nam Khanh
Published: May 2021

Trên thực tế, nếu đã từng nghiên cứu về các lý thuyết quản trị chiến lược doanh nghiệp thì đều dễ dàng nhận thấy “dường như không thể có chiến lược cho những doanh nghiệp siêu nhỏ”, điều đó có đúng không?
RESUME MATA KULIAH HAN
Authors: Raher Rahmat Hermawan
Published: May 2021

RESUME HUKUM ADMNISTRASI NEGARA
Open-mindedness in science education
Authors: Guzzo Guilherme Brambatti , Garcia Guilherme D.
Published: May 2021

Critical thinking is widely regarded as one of the main objectives of education in general terms, and also of science education. The idea of thinking critically, that is, to evaluate adequately and eventually embrace a certain claim only if there are good reasons for it, however, seems to contradict some popular conceptions about other educational ideal: open-mindedness. The purpose of this essay is to discuss how critical thinking and open-mindedness are not exclusionary ideals, and how those ideas are important for science education.
Ending the School-to-Prison Pipeline: Perception and Experience with Zero-Tolerance Policies and Interventions to Address Racial Inequality
Authors: Henry Kade-Ann , Catagnus Robyn , Griffith Annette , Garcia Yors
Published: May 2021

This study expands the current research on anti-Black racism and student discipline in schools. It examines perception, experiences, and alternatives of zero-tolerance policies in education, in relation to the call for action by Black Lives Matter at Schools. Black, Indigenous, and People of Color (BIPOC) students are impacted at a disproportionate rate when it comes to school discipline, leading to high, inequitable incarceration rates. However, behavior analysis already has powerful tools and interventions that can stop this ‘school-to-prison pipeline’ effect. A survey of school professionals investigated awareness of adverse outcomes from zero-tolerance policies and the use of effective, behavioral alternatives to exclusionary disciplinary practices. Results confirmed zero-tolerance policies still exist in North American schools, but that school professionals, including behavior analysts, support Black Lives Matter at School’s call to end such practices. Importantly, participants report already having the necessary skills to combat zero-tolerance; however, many still feel uncomfortable or ill-prepared to implement interventions specifically to decrease anti-Black racism in schools.
Thuyết “con nhím” trong khởi nghiệp kinh doanh thời đại cách mạng công nghiệp 4.0
Authors: Giao Ha Nam Khanh
Published: May 2021

Giáo dục 4.0 là một mô hình giáo dục thông minh, liên kết chủ yếu giữa các yếu tố nhà trường - nhà quản lý - nhà doanh nghiệp, tạo điều kiện cho việc đổi mới, sáng tạo và tăng năng suất lao động trong xã hội tri thức. Mô hình này cũng thúc đẩy tinh thần khởi nghiệp của giảng viên, sinh viên; tạo điều kiện cho việc hợp tác giữa giáo dục đại học và sản xuất công nghiệp; gắn kết phát triển kinh tế khu vực và địa phương… Đổi mới giáo dục đào tạo trước cuộc cách mạng công nghiệp 4.0 trong Trường Đại học giúp hoạt động dạy và học diễn ra mọi lúc và mọi nơi; giúp sinh viên có thể cá nhân hóa, hoàn toàn quyết định việc học tập theo nhu cầu của bản thân
Yêu cầu kỹ năng mềm của lao động trong thời kỳ hội nhập
Authors: Giao Ha Nam Khanh , Mo Nguyen thi Hong
Published: May 2021

Hội nhập sẽ mở ra nhiều cơ hội việc làm, dòng chảy lao động được tự do, nhiều yêu cầu cao hơn đối với người lao động, với tiêu chí tuyển dụng cao hơn đòi hỏi nguồn nhân lực ngoài kiến thức chuyên môn thì phải có kỹ năng mềm.
Meteorites that produce K-feldspar-rich ejecta blankets correspond to mass extinctions.
Authors: Pankhurst Matt , Stevenson Christopher , Coldwell Beverley
Published: May 2021

Meteorite impacts load the atmosphere with dust and cover the Earth‘s surface with debris. They have long been debated as a trigger of mass extinctions through Earth‘s history. Impact winters generally last <100 years, whereas ejecta blankets persist for 10^3-10^5 years. Here we show that only meteorite impacts that emplaced ejecta blankets rich in K-feldspar (Kfs) correlate to Earth system crises (n=11, p<0.000005). Kfs is a powerful ice-nucleating aerosol yet is normally rare in atmospheric dust mineralogy. Ice nucleation plays an important role in cloud microphysics, which modulates global albedo. A conceptual model is proposed whereby the anomalous prevalence of Kfs is posited to have two key effects on cloud dynamics: 1) reducing the average albedo of mixed-phase cloud, which effected a hotter climate; 2) weakening of the cloud albedo feedback, which increased climate sensitivity. These mechanisms offer an explanation as to why this otherwise benign mineral is correlated so strongly with mass extinction events: every K-feldspar-rich ejecta blanket corresponds to a severe extinction episode over the past 600 Myr. This model may also explain why many kill mechanisms only variably correlate with extinction events through geological time: they coincide with these rare periods of climate destabilization by atmospheric Kfs.
A re-examination of the mechanism of whiting events: A new role for diatoms in Fayetteville Green Lake (New York, USA)
Authors: Stanton Chloe , Cosmidis Julie , Kump Lee
Published: May 2021

Whiting events – the episodic precipitation of fine-grained suspended calcium cabonates in the water column – have been documented across a variety of marine and lacustrine environments. Whitings likely are a major source of carbonate muds, a constituent of limestones, and important archives for geochemical proxies of Earth history. While several biological and physical mechanisms have been proposed to explain the onset of these precipitation events, no consensus has been reached thus far. Fayetteville Green Lake (New York, USA), is a meromictic lake that experiences annual whitings. Materials suspended in the water column collected through the whiting season were characterized using scanning electron microscopy and scanning transmission X-ray microscopy. Whitings in Fayetteville Green Lake are initiated in the spring within the top few meters of the water column, by precipitation of fine amorphous calcium carbonate (ACC) phases nucleating on Synechococcus cells (cyanobacteria), as well as on extracellular polymeric substances (EPS), including abundant β-chitin fibrils exuded by centric diatoms. Whiting particles found in the summer consist of 5-7 µm calcite grains forming aggregates with diatoms and their EPS. Simple calculations demonstrate that calcite particles continuously grow over several days, then sink quickly through the water column. In the late summer, partial calcium carbonate dissolution is observed deeper in the water column. Settling whiting particles however reach the bottom of the lake, where they form a major constituent of the sediment, along with diatom frustules. The importance of diatoms and their EPS in whitings at Fayetteville Green Lake is described for the first time here, a largely overlooked mechanism for other whiting events in modern and ancient environments.
Meat disgust is negatively associated with meat intake - evidence from a cross-sectional and a longitudinal study
Authors: Becker Elisa , Lawrence Natalia
Published: May 2021

Meat consumption is increasingly seen as unsustainable, unhealthy, and unethical. Understanding what factors help people reduce their meat intake is urgently needed. One such factor is meat disgust, a feeling reported by many vegetarians, and which could be a promising basis for meat reduction interventions. However, meat disgust and its impact on meat consumption is poorly understood. We examined meat disgust and its role in vegetarianism and reducing meat intake in a cross-sectional and longitudinal online study. We measured self-reported meat consumption, meat disgust (by self-report and Implicit Association Test), meat liking, self-control, and disgust sensitivity in N=711 adults (57% omnivores, 28% flexitarians, 15% vegetarians) recruited from a community cohort. Results showed that 73% of vegetarians can be classified as ‘meat disgusted’, and that meat disgust predicted meat intake better than self-control in omnivores and flexitarians at baseline. Following up a sub-sample of participants (N=197) after six months revealed that changes in meat intake over time were also associated with changes in meat disgust. This is the first study to quantify the impact of meat disgust on (changes in) meat consumption and its prevalence in the vegetarian and the general population. Our findings advance research into meat disgust and encourage the development of disgust-based interventions to reduce meat intake.
Testing the Effects of the Shamiri Intervention and its Components on Anxiety, Depression, Wellbeing, and Academic Functioning in Kenyan Adolescents: Study Protocol for a Five-Arm Randomized Controlled Trial
Authors: Venturo-Conerly Katherine E. , Osborn Tom L , Wasil Akash R , Le Huong , Corrigan Emily , Wasanga Christine , Weisz John R.
Published: May 2021

Background: Treatments for youth mental disorders are a public health priority, especially in sub-Saharan Africa (SSA), where treatment options remain limited due to high cost, elevated stigma, and lack of trained mental health professionals. Brief, accessible, and non-stigmatizing community-based interventions delivered by lay-providers may help address treatment needs in SSA. One such intervention, the Shamiri Intervention, consisting of three elements (growth mindset, gratitude, and value affirmation) has been tested in randomized controlled trials with school-going Kenyan adolescents. This three-element Shamiri Intervention has been shown to significantly reduce depression and anxiety symptoms and improve social support and academic performance relative to a control group. In this trial, we aim to investigate the effects of each element of the Shamiri Intervention.Methods: In this five-arm randomized controlled trial, we will test each of the intervention components (growth mindset, gratitude, and value affirmation) against the full Shamiri Intervention and against a study-skills control intervention. Students (Nplanned=1288) at participating secondary schools who are interested in participating in this universal intervention will be randomized in equal numbers into the five groups. The students will meet in groups of 8-15 students led by local high school graduate lay-providers. These lay-providers will receive 10 hours of training, plus expert supervision once a week throughout the intervention delivery. Multi-level models will be used to compare trajectories over time of the primary outcomes (depressive symptoms, anxiety symptoms, academic performance, and wellness) and secondary outcomes in each intervention group to the control group. Multi-level models will also be used to compare trajectories over time of the primary outcomes (depressive symptoms, anxiety symptoms, academic performance, and wellness) and secondary outcomes of those in the single-element interventions compared to the full Shamiri Intervention. Finally, effect sizes (calculated as mean gain scores) will be used to compare all groups on all measures. Discussion: This trial will shed light on the mechanisms and outcomes targeted by each individual intervention, helping prioritize which mental health interventions are most important to disseminate.
The Impact of Study and Learning Strategies On Post-Secondary Student Academic Achievement: A Mixed-Methods Systematic Review
Authors: Xu Joy , Ong Jeffrey , Tran Tam , Kollar Yasmine , Wu Alyssa , Vujicic Milena , Hsiao Helen
Published: May 2021

BACKGROUNDWithin academic development, it is important for students to use effective study strategies to facilitate learning. Techniques used for long-term information retention include note taking strategies, time management, methods of self-testing and active recall. These strategies are explored to help students learn more effectively to attain their academic goals.METHODA mixed-methods systematic review of peer-review articles and grey literature was conducted with a predetermined criteria for a convergent integrated synthesis approach. PsychInfo (Ovid), Web of Science, and ProQuest databases were searched with guidance of a PICO-P logic grid and search strategy using keywords of student, study strategies, and achievement alongside filters. Initial studies were screened and reconciled by two independent authors with the use of a piloted screening tool. Using the Mixed Methods Assessment Tool (MMAT), included studies were assessed for quality. Two authors independently performed data extraction. Heterogeneity in study designs, outcomes, and measurements precluded meta and statistical analyses; thus, a qualitative analysis of studies was provided.RESULTSFour major themes contributing to academic performance were identified among the appraised articles. These themes were self-testing, scheduling/time management, concept maps, and learning styles. Self-testing, scheduling, and concept maps were positively correlated with increased academic performance, while no correlation was found with learning styles and academic performance.CONCLUSIONIncluded studies provided evidence for significant differences in study strategies implemented by high and low achieving students, such as areas of motivation for learning, efficiency, active recall, retrieval practices, and concept maps. Understanding the effectiveness of certain study strategies is critical for students and educational facilitators to maximize learning.
Effective Virtual Interventions to Enhance Psychological Capital: A mixed-methods systematic review
Authors: Xu Joy , Qureshi Aljeena Rahat , Dabagh Yar Mohamed Al , Kin Cynthia Lai , Khan Rida
Published: May 2021

BACKGROUNDDeveloped from positive psychology, Psychological Capital (PsyCap) entails a collection of intrinsic traits which may be optimized for productive and sustainable outcomes in life. This systematic review explores potential virtual implementation of PsyCap interventions, especially given the digital transition amidst the COVID-19 pandemic and its potential usage in the future.METHODSUtilizing a mixed-methods systematic review, this convergent integrated synthesis involves database searches conducted in APA PsychINFO, Web of Science and PubMed with literature published between 1995 and 2020. This systematic review follows the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines with a registered PROSPERO protocol. With diverse study designs and accompanying grey literature, heterogeneity precluded statistical analysis for qualitative presentation of included studies. Study screening, extraction, and quality appraisal (using the Mixed Methods Appraisal Tool) were performed by two authors independently and reconciled. Disagreements were resolved by a third author.RESULTSPresent literature has determined effective increase of PsyCap with the PCI Intervention Model. Strengths-based interventions assisted in identifying individual recognition in strengths to maximize potential and increase PsyCap. Other interventions have been found to support hope, self-efficacy, resilience, or optimism (HERO).CONCLUSIONOverall, interventions from included studies showed effective improvement in HERO elements and increased PsyCap in individuals in academia and the workplace. In the context of the COVID-19 pandemic and future application, PsyCap interventions may be further explored and modified for virtual implementation for young adults.
A cross-linguistic study on orthographic influence during auditory word recognition.
Authors: Furgoni Alberto , Martin Clara D. , Stoehr Antje
Published: May 2021

Learning to read affects speech perception. For example, the ability of listeners to recognize consistently spelled words faster than inconsistently spelled words is a robustfinding called the Orthographic Consistency Effect (OCE). Previous studies located the OCE at the rime level and focused on languages with opaque orthographies. This study investigates whether the OCE also emerges at the phonemic level and is a general phenomenon of languages with alphabetic scripts, including those with transparentwriting systems. Thirty French (opaque language) and 30 Spanish (transparent language) listeners participated in an auditory lexical decision task featuring words and pseudowords including either only consistently spelled phonemes or also inconsistently spelled phonemes. Our results revealed an OCE in both French and Spanish whichsurfaced as longer reaction times and higher error rates in response to inconsistently spelled words and pseudowords. These findings have two theoretical implications.First, they show that auditory lexical processing is impacted by orthographic information that is retrieved at the phonemic level, not just the rime level. Second, they suggest that the OCE is elicited during auditory processing of alphabetic languages regardless of their opacity level. In conclusion, our study highlights the depth of literacy effects on auditory language processing.
Characterizing underlying cognitive components of ADHD presentations and co-morbid diagnoses – A diffusion decision model analysis
Authors: Ging-Jehli Nadja , Arnold L. Eugene , Roley-Roberts Michelle E. , deBeus Roger
Published: May 2021

Objective. To Explore whether subtypes and comorbidities of attention-deficit hyperactivity disorder (ADHD) induce distinct biases in cognitive components involved in information processing. Method. Performance on the Integrated Visual and Auditory Continuous Performance Test (IVA-CPT) was compared between 150 children (aged 7-10 years) with ADHD, grouped by DSM-5 presentation (ADHD-C, ADHD-I) or co-morbid diagnoses (anxiety, oppositional defiant disorder [ODD], both, neither), and 60 children without ADHD. Diffusion decision modeling decomposed performance into cognitive components. Results. Children with ADHD had poorer information integration than controls. Children with ADHD-C were more sensitive to changes in presentation modality (auditory/visual) than those with ADHD-I and controls. Above and beyond these results, children with ADHD+anxiety+ODD had larger increases in response biases when targets became frequent than children with ADHD-only or one comorbidity. Conclusion. ADHD presentations and comorbidities have distinct cognitive characteristics quantifiable using DDM and IVA-CPT. We discuss implications for tailored cognitive-behavioral therapy.
How expectations shape the formation of intrusive memories – An experimental study using the trauma film paradigm
Authors: Herzog Philipp , Barth Charlotte , Rief Winfried , Brakemeier Eva-Lotta , Kube Tobias
Published: May 2021

Objective: Although intrusions are the hallmark symptom of Posttraumatic Stress Disorder (PTSD), there is still limited knowledge about the processes that contribute to the development of intrusions. Here, we used the well-established trauma film paradigm (TFP) to investigate how expectations about the intensity and controllability of intrusions influence their occurrence. Methods: 90 healthy participants underwent the TFP before they were randomized to one of three conditions manipulating their expectations about intrusions: positive expectations group; negative expectations group; control group. The primary outcome was the frequency and severity of intrusive memories as assessed with an intrusion diary over seven days.Results: The TFP was well implemented, as indicated by significant post-film anxiety and a substantial number of intrusions reported for the subsequent week. The three groups did not differ in their expectations about intrusions and, relatedly, in their experience of intrusions. A mediation analysis revealed that the influence of post-film anxiety on intrusive memories was fully mediated by expectations. Conclusion: Despite the failure of the expectation manipulation, the results of the mediation analysis support the hypothesis that post-film expectations influence the formation of intrusive memories, suggesting that intrusions may result from maladaptive dynamics between emotional and cognitive processes following trauma(like) experiences.
Assessing the carbon footprint of tourism businesses using Environmentally Extended Input-Output analysis
Authors: Demeter Csilla , Lin Pei-Chun , Sun Ya-Yen , Dolnicar Sara
Published: May 2021

The tourism industry contributes eight percent to global carbon emissions, directly and indirectly. Indirect carbon emissions are often neglected because they are difficult to calculate. The traditional approach to calculating indirect emissions – Life Cycle Assessment – is expensive and requires an expert data analyst. We introduce an alternative approach, the Environmentally Extended Input-Output Analysis. We show how this approach – currently used at macro-level to estimate carbon emissions at national or regional level – can be applied to the business level using carbon emissions generated by one hotel room clean as an example. Our comparative analysis shows that Environmentally Extended Input-Output Analysis leads to similar results as Life Cycle Assessment, while being substantially cheaper and more user-friendly. Environmentally Extended Input-Output Analysis, we conclude, enables tourism businesses to estimate the indirect carbon emissions of their operations, which is the key to identifying target areas for improvement.
SELAYANG PANDANG MENGELOLA SUMBER DAYA MANUSIA DI LINGKUNGAN PERUSAHAAN
Authors: MADIISTRIYATNO HARRIES
Published: May 2021

Oganisasi dapat didefiniskan sebagai sebagai wadah tempat di mana dua orang atau lebih bekerja sama secara terstruktur untuk mencapai tujuan, maka dapat dipastikan bahwa tanpa tujuan tidak perlu ada organisasi. Tujuan organisasi bermacam-macam, tergantung dari banyaknya pihak yang berkepentingan (stakeholders) dengan kehadiran organisasi itu. Pihak-pihak yang berkepentingan itu antara lain, terdiri atas para pemegang saham, karyawan, pemasok, pemakai, pemerintah, dan masyarakat. Tujuan organisasi bagi pemegang saham adalah untuk meningkatkan keuntungan. Bagi konsumen adalah untuk meningkatkan kualitas pelayanan, bagi masyarakat adalah untuk meningkatkan rasa tanggung jawab kepada masyarakat, dan bagi pemerintah adalah untuk meningkatkan penerimaan pajak. Bagi karyawan adalah untuk meningkatkan kepuasan kerja karyawan agar pada gilirannya dapat meningkatkan prestasi kerja karyawan dan juga kinerja organisasi.
Effects of maize residue removal on soil quality and greenhouse gas emissions in Iowa
Authors: Al-Kaisi Mahdi , Guzman Jose
Published: May 2021

Maize residue is an important component of soil carbon (C) budget and development of soil quality indices. However, maize residue in recent years has been considered as another potential feedstock source for ethanol production in addition to or alternative to maize grain. The current emphasis on using maize residue as a feedstock for future ethanol production presents a soil and environmental challenge that needs to be addressed. Additionally, there have been few studies that examine greenhouse gas (GHG) emissions from agriculture soils under different residue removal rates, various N rates, and tillage practices and their interactions effects on soil C dynamics and GHG emissions. The objective of this study was to examine potential changes in soil C sequestration and GHG emissions under no-tillage (NT) and conventional tillage (CT) and nitrogen fertilization rates of 0, 170, and 280 kg N ha-1 with variable rates of residue removal (0, 50, and 100%). Field studies were established in fall of 2008 on two sites, a poorly-drained soil at the Iowa State University Agronomy Research Farm (North central, IA) and a well-drained soil at the Armstrong Research and Demonstration Farm (Southwest, IA) in continuous maize. After two years of residue removal, soil C, water inﬁ ltrations, aggregate stability and bulk density was measured. After every harvest, crop measurements included maize grain yield, above-ground biomass, and root-biomass. Weekly measurements of soil surface CO2, and N2O emissions coupled with soil moisture and temperatures were collected. Additionally, C budgets were calculated for different treatments. These measurements provide insights on whether these management practices resulted in net gains or losses of C sequestration and atmospheric CO2. Findings suggest that sites for this study were a signiﬁcant net sink for atmospheric CO2-C, even when maize residue was removed and under different tillage and N fertilization (when applied) management. Applications of N had the largest effect on N2O-N emissions, where greater N2O-N emission was associated with high N rates. In addition, signiﬁcant declines in soil quality properties were observed after only two years of residue removal. The severity of soil quality deterioration due to residue removal varied with different tillage and N managements.
Potential of the daycent model to predict change in greenhouse gas emissions with cessation of tillage for cultivation of perennial energy crops
Authors: Thomas Amy , Hiscock Kevin , Bond Alan
Published: May 2021

Bioenergy may make up a signiﬁ cant proportion of future renewable energy supplies, and for perennial feedstocks, this will require conversion of land to a no till (NT) system. Previous studies suggest that NT leads to increased soil organic matter (SOM) storage, which breaks down over time resulting in increased N2O emissions. This may not indicate net total increase, since indirect emissions from eroded SOM with tillage should be considered. Given the high global warming potential of N2O, it is crucial to predict net change in emissions rather than focusing only on potential for C storage. The DayCent model has been used to represent both tilled [1, 2], and untilled [3, 4] agroecosystems. This study assesses its suitability to represent land conversion to NT; ﬁ rst by exploring model structure and process representation, and secondly by using sensitivity analysis to identify whether DayCent matches published variation between tillage regimes. DayCent predicts increasing surface and slow-decomposing soil carbon for no till, but not the expected increase in N2O emissions. It has been suggested that changes in soil structure with tillage affect inﬁ ltration, and therefore nitriﬁ cation and denitriﬁ cation processes leading to N2O emissions [5, 6]. For accurate simulation of the relationship to precipitation, DayCent should ideally represent differing soil water capacity (SWC) and porosity between tillage regimes, and the impacts on water ﬁlled pore space (WFPS). DayCent also fails to appropriately respond to low C:N ratio residue applications, or to simulate interaction between tillage and nutrient applications. Recommendations are provided for improvements to DayCent to resolve these issues and enable more robust scenario analysis. Assuming improved performance at validation, this should facilitate more accurate carbon equivalent emissions for land use change, incorporating N2O.
CO2 emissions of peat soils in agricultural use: calculation and prevention
Authors: Van den Akker J. J. H. , Hendriks R. F. A. , Pleijter M.
Published: May 2021

About 9% of the area of the Netherlands is covered by peat soils (about 290,000 ha), mainly drained and in use for dairy farming (about 223,000 ha). Decomposition (oxidation) of peat soils used in dairy farming causes subsidence rates of 12 mm.y-1 The objective of the research was to develop a method to calculate from subsidence the CO2 emissions of peat soils in agricultural use and to test the possibilities of submerged drains to raise groundwater levels and diminish subsidence and CO2 emissions. One mm subsidence by oxidation equals a CO2 emission of about 2.3 tons of CO2 per year per hectare. We calculated that about 3% of the annual anthropological CO2 emission in the Netherlands can be accounted to the oxidation of peat soils. This is about 4.2 Mton CO2 per year. In dry summers the groundwater level lowers well below ditchwater levels, exposing easily biological degradable peat to oxidation. Raising groundwater levels up to ditchwater levels by subsurface irrigation by submerged drains with a spacing from drain to drain of 4 to 6 meters is tested as a possibility to reduce subsidence and CO2 emissions. The experiments started in 2003. Subsidence and so CO2 emissions proved to be reduced by more than 80%. A disadvantage of the use of submerged irrigation might be the increased water usage. Model calculations showed that the amount of inlet water increased on average up to 30%, however, intelligent water management can be a possibility to reduce the extra water usage to about 5%. The modeled reduction in subsidence (and so the CO2 emission) was about 40% of the subsidence in the situation without submerged drains. We concluded that the use of submerged drains can reduce subsidence and CO2 emissions with at least 50%.
Clay soil moisture in spring cereal cultivation as related to tillage management
Authors: Alakukkua L. , Koivula V. , Palojärvi A.
Published: May 2021

Conservation tillage with crop covered soil surface has been found to reduce the risk of erosion and nutrient leaching. The reduction of tillage intensity changes topsoil structure affecting soil physical conditions relevant to crop growth. In this study, the effects of autumn tillage management on soil moisture during the growing season of spring barley (Hordeum vulgare) was examined on two ﬁ eld experiments on clay soils (Vertic Cambisol, Eutric Cambisol) in southwestern Finland in 2004–11. The objective of the study was to investigate the effects of reduced tillage intensity on soil moisture conditions of two different clay soils in different weather conditions. Autumn mouldboard ploughing (to 20–25 cm depth, P) was compared to stubble cultivation (10–15 cm, S) and zero tillage (N). During the growing season, soil moisture was determined once a week at the depth of 0−30 cm with a TRASE system I (Time Domain Reﬂ ectometry (TDR)). Daily weather conditions (precipitation, air temperature) were also determined. Zero tilled soil stayed moister than the soil in other tillage treatments. When the beginning of the growing season was dry, higher soil moisture content in zero tilled soil improved the growth conditions of barley. In an unexceptional rainy beginning of growing season, the wetness of clay soils in zero tilled treatment hampered the crop growth and yield production clearly.
Soil nutritional survey for soybean production in Uruguay
Authors: Bordoli J. M. , Barbazán M. M. , Rocha L.
Published: May 2021

The recent changes in the agriculture in Uruguay, by the adoption of no-tillage planting systems, have included the use of marginal soils for crop production, being the soybean the main crop that allowed those changes. Several questions have arisen about the sustainability of the intensive soil use of these new production systems. The objective of this work was to detect situations with greater probability of nutrient defi ciencies, using soybean as indicator crop. During crop seasons 2009/10 and 2010/11 a nutritional soil survey of soybean crops was conducted, collecting soil and leaf samples of 178 commercial fi elds widely distributed around the country, at the R1-R2 soybean growth stage. In half of the sites soybean was the main crop, and in the other half soybean was planted following winter crops. Soybean yield ranged from 511 to 5435 kg ha-1. In 34% of the fi elds pH was below 5.3, even in the traditional agricultural zone. In 54% of fi elds available P was below 12 mg kg-1 of P Bray-1, and 23% of the cases were below 0.30 cmolc kg-1 of exchangeable K. The concentrations of macronutrients in leaves for all the samples were: 3.88 (±0.66) % N; 0.26 (± 0.08) % P; 2.03 (±0.53) % K; 1.14 (±0.23) % Ca; 0.36 (±0.10) % Mg; and 0.29 (±0.07) % S. The micronutrient concentration means were 9, 77, 61, and 30 mg kg-1 of Cu, Fe, Mn, and Zn, respectively. The more frequently defi cient nutrients were P, K, and N, with 42, 39, and 13% of the fi elds with concentrations in leaves below the critical concentrations. The results show that the actual soybean productivity could be partially affected by nutrient defi ciencies, suggesting that soil pH, and P or K corrections need to be considered in the nutritional management program for each crop production system.
Citrus soil management can reduce the deterioration of soil conditions and improve sustainability production
Authors: Goñi C. , Otero A.
Published: May 2021

Long term traditional herbicide uses for soil management brings soil compaction, crusting, poor infiltration and week rooting trees, leading to orchard deterioration and poor soil sustainability. The amelioration of the soil properties and plant growing condition was evaluated on a young rainfed citrus orchard of Valencia late (NVA 036) grafted on Poncirus trifoliate rootstock during three years, planting on an Argisol Districo Ocrico soil. A combination of organic mulch (rows) and sod cultivation (between rows) were applied. A 75 cm wide row with two organic mulch sources was used: a) composted Eucalyptus wood chip (52 kg m-2) with a C/N ratio of 1.5, and b) commercial compost (30 kg m-2 ) with a C/N of 10. Between row treatments sod consisted in a) Ornithopus compressus, and b) Lolium multifl orum. The traditional herbicide application in the row and the spontaneous vegetation between rows were the control. Soil organic matter, nitrogen mineralization potential and soil biomass have not changed in the row for the first 4 years. However, the use of mulch significantly reduces the amplitude of soil temperature, at the 15 cm depth and holds up soil water availability more time than the herbicide application. During summer drought, stem water potential of the trees under mulch varies between -1.4 to -2.2 MPa compared with the - 3.5 to -3.8 MPa with the herbicide. Sod dry matter accumulation was variable between years, and has not significant effect in the physical and chemical properties to the present. Mulches have generated better tree growing conditions than the herbicide, resulting in significant increments in tree vigor, precocity, and yield. Wood chip mulch has increased 42% the accumulated crop yield, enhances fruit color and reduced the need of weed control. Mulch application seems to be a promising soil management measure for citrus young trees in this soil and climate conditions.
Evaluación de la vulnerabilidad de los suelos del estado de Durango, México en el contexto del cambio climático
Authors: López-Santos Armando , Sánchez Cohen Ignacio , Esquivel Arriaga Gerardo , González Barrios José Luis
Published: May 2021

Se evaluó el grado de vulnerabilidad actual y futura de los sistemas naturales y agroproductivos de Durango, México ante los impactos probables del cambio climático. Esta investigación comprende todo el territorio (123,181 Km2) duranguense (26.8° y 22.316° latitud Norte; -102.466° y -107.183 longitud Oeste), donde se distinguen dos zonas climáticas: templado (36%) y tropical seco (64%). Las tasas de erosión hídrica laminar histórica (TEHLH) fue calculada mediante la ecuación universal de pérdida de suelo (EUPS) calibrada para México, y la tasa de erosión hídrica laminar para el escenario futuro más extremo, A2 (TEHLA2) se empleó la técnica de reducción de escala mediante el SDSM (Statistical Downscaling Method), usando registros climáticos de 29 Estaciones del Servicio Meteorológico Nacional Mexicano (EM-SMN) para representar los distintos ambientes que lo caracterizan. Se estima que por su condición de exposición los suelos de Durango históricamente han perdido un promedio de 163.8 ton.ha-1.año-1 y en el escenario futuro para el periodo 2010-2039 es probable una disminución promedio anual menor al 5%. En el escenario A2 hay una alta probabilidad de lluvia más escasas e incremento de la temperatura promedio, circunstancia bajo la cual las prácticas de uso y cambio de uso del suelo (pecuario ↔ forestal ↔ agrícola) tendrán que ser cuidadosamente planiﬁcadas; asimismo, una menor disponibilidad humedad en el suelo tendrá como consecuencia un incremento en la vulnerabilidad del suelo a la erosión eólica.
Main mechanisms involved in the effects of humic substances on soil-plant systems
Authors: Garcia-Mina J. M. , Mora V. , Olaetxea M. , Baigorri R. , Fuentes M. , Garnica M. , San Francisco S. , Erro J. , Urrutia O. , Casanova E. , Lemenager D. , Yvin J. C.
Published: May 2021

A number of studies have shown the ability of natural organic matter (NOM) in general and humic substances (HS) in particular, to affect the development of plants and microorganisms in many different natural ecosystems and agroecosystems. Regarding plants, these NOM and HS effects were expressed in both root growth and architecture, and shoot growth. However, these effects were different in intensity and quality depending on several intrinsic and extrinsic factors associated with HS structure and concentration, plant species and soil properties. Two main mechanisms have been proposed to explain the beneficial action of NOM and HS on plant growth. An indirect effect expressed through the improvement of plant nutrition by increasing soil nutrient availability, principally some micronutrients (mostly P and Fe); and a possible direct action affecting the transcriptional and post-transcriptional regulation of several enzymes and molecular transporters in the root. These biological effects within the plant seem to be associated with both nutrient root uptake ability and the efficient use of the nutrient in plant leaves. In this communication, the relationships between the effects of HS on root development, shoot development, plant nutrition, and soil properties; are discussed. This study is developed in the context of the links existing between the signal role of some nutrients and the hormonal balance in both root and shoot.
Spatial and temporal variability in soil physical conditions for root growth: interactions between soil, water and root growth for sustainable agriculture
Authors: McKenzie Blair M.
Published: May 2021

Plants and hence crops grow best when their roots are able to proliferate through soft stable soil. Crops with prolific root systems use water and nutrients efficiently, generally have greater yields and are best placed to resist or minimise disease. For most plants, physical constraints including mechanical impedance, water stress and oxygen deficiency limit root proliferation. However these constraints differ with location in the soil and change with time. Roots may exploit structural cracks and biopores in the soil and by so doing gain access to water and other resources at depth, but to fully exploit the soil resources roots must not be confined to these largest of pores and must explore the soil matrix. A range of sensors are available to quantify the physical constraints for roots, but penetrometers of similar dimensions to a root and with a relieved shaft to limit friction between the shaft and the soil are best able to described the condition of the soil matrix for root proliferation. To penetrate the soil matrix a root requires both to expand the cavity it is to occupy and to overcome the soil-root friction. While cavity expansion is determined solely by the soil, the soil-root friction involves both the plant and the soil. This paper will start at the scale of an individual root tip elongating into the soil matrix, consider how the physical environment changes that elongation, and the consequences of soil variability in space and time for the individual root. Using the understanding of the individual root-soil interaction it will draw inference for larger scales, comment on how the understanding informs sustainable soil management and finally emphasise the need to deploy plant genetics and soil management together to improve long-term productivity.
Deep loosening for direct drilled soil recovery
Authors: Terminiello A. , Palancar T. , Draghi L. , Balbuena R. , Jorajuria D.
Published: May 2021

Maintaining a sustainable soil management system with annual double cropping is a considerable challenge, even when a conservation technique such as direct drilling is used. No tillage means less vehicular traffic, but not necessarily a reduction in traffic intensity because of the excessively high axles loads associated with some agricultural machines. Direct drilled soils appear to have a better recovery following agricultural traffic, but evidence has suggested that problems related to compacted layers occur in these profiles with time. Subsoiling, as a well known technique to alleviate soil compaction, has been widely quoted for tilled soils, but rather little is known about how no tilled soils respond to this technique. The task is to loosen compacted subsoil layers, with minimal disturbance of the topsoil to avoid subsequent problems during drilling. Research was performed on a fine Typic Argiudol soil managed with no tillage, annual double cropping and with and without deep loosening. Both soil treatments received the standard traffic demanded by the cropping system. Soil penetration resistance and dry bulk density were the dependant variables assessed. Results showed that although there was a major compaction tendency after traffic on loosened soil, there was also evidence that the effects of loosening persisted for almost nine months. Interestingly, it was also evident that layers below the mechanically loosened horizon exhibited a reduction in penetration resistance and bulk density. It was concluded that periodic subsoiling can alleviate the soil compaction caused by agricultural traffic in deep soil layers and will allow direct drilling to continue sustainably. Subsoiling not only alleviates compaction in the mechanically disturbed layers, but also in the horizon immediately below.