Search

Bamboo forests present a novel nature-based strategy to remove atmospheric carbon dioxide thanks to their extraordinary carbon sequestration capacity. In particular, Moso bamboo (Phyllostachys edulis) sequesters more than 40 tonnes of carbon dioxide per hectare annually. However, these forests have encountered challenges in some areas due to decentralized management and industry downturns. An innovative green financing model incorporating village cooperatives could address the critical problems facing the management of bamboo forests while contributing to the mitigation of the climate crisis. Meanwhile, the model will significantly benefit the less-developed communities in many parts of the world by increasing farmers’ incomes, enhancing livelihood, and boosting local economies.

In the last few decades, various types of farming systems based on ecological principles have been proposed and developed. There is often interest in knowing about the differences between these systems, but such information must be obtained from several sources describing each of these systems. Therefore, this paper is an effort to consolidate the information on these systems in a concise manner without making comparative ratings between them. We found three components contained in the overarching theme of these systems: the reduction in external inputs, environmental protection, and sustainability. However, several variations exist between them, each with its own focus and guiding principles. Also, these farming systems contain their own specific terms to identify themselves and contain their own set of philosophies based on their founder. In this review, we provided a short description of some of the major ecologically based farming systems such as “agroecology”, “regenerative agriculture”, “holistic management”, “carbon farming”, “organic farming”, “permaculture”, “biodynamic farming”, “conservation agriculture”, and “regenerative organic farming”. We summarized these farming systems as “variants of farming systems based on ecological principles” and outlined the similarities and differences between them. We also discussed how the themes of these systems relate to the United Nations’ thirteen principles of agroecology. Although these systems share several similarities, their philosophy is rooted in their founders and the communities that choose to adopt these philosophies. Last, we discussed some of the challenges in implementing these ecological agriculture systems.

Abstract Purpose The aim of this study is to evaluate the outcomes of retrograde intra renal surgery (RIRS) in the setting of large or multiple stones in children (15 mm, or both. Outcomes included stone free rate (SFR) and complications within 30 days. Results In total, 344 patients were included with 197 and 147 in Groups 1 and 2, respectively. Ureteric access sheaths were more frequently used in Group 2 (39.5% vs. 56.8%, p = 0.021). The operation time was significantly longer in Group 2 (p

The potential of terminating cover crops with a roller-crimper is of increasing interest. A two-year (2020/21 and 2021/22) study was conducted in Fresno, CA, USA. Five cover crop treatments (rye (Secale cereale L.) alone, ultra-high diversity mix, multiplex cover crop mix, fava bean (Vicia faba L.) + phacelia (Phacelia tanacetifolia Benth.), and rye + field pea (Pisum sativum L.) + purple vetch (Vicia americana Muhl. Ex Willd.)) were planted in November, roller-crimped in April, and silage maize (Zea mays L.) was strip-till planted in the residue in May. Cover crop kill, soil cover by residue, weed cover, amount of organic residue, and silage maize yield were recorded. The roller-crimper resulted in 95 to 100% kill of the cover crops. Soil cover at maize canopy closure (mid-July) was approximately 90% in the rye plots while it was 30 to 70% in the other treatments. The fava bean + phacelia cover crop disintegrated the most rapidly. Weed cover was −1 of residue. Maize silage yield was similar across the treatments. Therefore, in this study, cover crops were successfully terminated by the roller-crimper, allowing successful strip-till establishment and production of silage maize.

Abstract. Background. Emphysematous pyelonephritis (EPN) is a necrotizing infection of the kidney and the surrounding tissues associated with considerable mortality. We aimed to formulate a score that classifies the risk of mortality in patients with EPN at hospital admission. Materials and methods. Patients diagnosed with EPN between 2013 and 2020 were retrospectively included. Data from 15 centers (70%) were used to develop the scoring system, and data from 7 centers (30%) were used to validate it. Univariable and multivariable logistic regression analyses were performed to identify independent factors related to mortality. Receiver operating characteristic curve analysis was performed to construct the scoring system and calculate the risk of mortality. A standardized regression coefficient was used to quantify the discriminating power of each factor to convert the individual coefficients into points. The area under the curve was used to quantify the scoring system performance. An 8-point scoring system for the mortality risk was created (range, 0–7). Results. In total, 570 patients were included (400 in the test group and 170 in the validation group). Independent predictors of mortality in the multivariable logistic regression were included in the scoring system: quick Sepsis-related Organ Failure Assessment score ≥2 (2 points), anemia, paranephric gas extension, leukocyte count >22,000/μL, thrombocytopenia, and hyperglycemia (1 point each). The mortality rate was

Background: There is continued research to find new faster, highly accurate, easily accessible, and portable methods of confirming endotracheal tube position during intubation. A newer modality for visualizing endotracheal tube location is transtracheal or transcricothyroid ultrasonography. The aim of this study was to see if ultrasound machine can also be routinely used for the confirmation of endotracheal tube position in operating theaters along with capnograph. Methods: The study was observational and prospective, conducted from January 2017 to July 2017. Study locations were at the Tribhuvan University Teaching Hospital and Manmohan Cardiothoracic Vascular and Transplant Center operating rooms. Sample size taken was 95. Results: In the study, 11 patients had esophageal intubation out of the 95. The accuracy of both ultrasonography and capnography was found to be 96.84%. For ultrasonography, the sensitivity, specificity, along with positive predictive value and negative predictive value were 97.62%, 90.91%, 98.80%, and 83.33%, respectively, while that for capnography were found to be 96.43%, 100%, 100%, and 78.57%, respectively. The kappa value was calculated to be 0.749, which suggested the degree of agreement of result between the methods to be good. Compared to capnography, ultrasonography was found to be significantly faster for the confirmation of endotracheal tube location by 16.36 s (15.70–17.02) (P = 0.011). Conclusion: Both waveform capnography and ultrasonography were found to be accurate and reliable in confirming endotracheal tube location. The use of ultrasound during intubation can help confirm endotracheal tube location faster and also aid in precision when used along with capnography. Manual bag ventilations are not necessary when confirming endotracheal tube position by ultrasonography and thus may help in preventing aspiration of gastric contents into the lungs of the patient.

Land use and land cover change (LULCC) is crucial in sustainable land management. Over the past four decades, the Min River Basin (MRB) has experienced significant LULCC. This study investigated the dynamics of LULCC over these decades (1980–2020) and discusses the key drivers of land use change in different stages. First, we mapped and quantified changes (i.e., LULCC and landscape indices) in forests, croplands, urban areas, and water bodies from 1980 to 2020 using the China National Land Use/Cover Change (CNLUCC) and ArcGIS Pro 2.3. Second, by analyzing existing policies, we categorized four decades of LULCC trends from 1980 to 2020, delineating three distinct stages: (1) the Economic Restoration (ER) stage (1978–1989), when the ecological impacts of LULCC on forests, croplands, and water bodies received limited policy attention; (2) the Construction of Ecological Protection and Economic Development (EPED) stage (1989–2012), which saw a significant increase in forest coverage, primarily driven by various central and provincial environmental conservation policies, such as the Green for Grain and the “Three-Five-Seven Reforestation Project” in Fujian; and (3) the Ecological Civilization (EC) stage (2012–2020), in which policy focus shifted from expanding forest land areas to enhancing the quality of these areas. However, the cropland area has decreased due to urbanization policies and population migration from rural to urban areas, including the above-mentioned forest policies. Thus, this study highlights the complex relationship between different land use land cover policies, as some policies had synergistic effects between the policies and positive outcomes, while other policies showed conflicting outcomes. Our results emphasize the importance of integrated land and water resource management and provide insights for policymakers to balance development and environmental conservation policies in the MRB.

A long-term annual crop study in Five Points, California, shows that the combined use of no-tillage, surface residue retention, and cover crops improves soil health compared to conventional practices common to the region. Several chemical, biological, and physical soil health indicators were improved when these practices were combined. Our data suggest that farmers stand to gain multiple synergistic benefits from the integrated use of these practices by increasing soil structural stability, water infiltration and storage, and agroecosystem biodiversity, and improving the efficiencies of the carbon, nitrogen, and water cycles of their production systems.

California farmers who use reduced-disturbance tillage and winter cover cropping can boost production and improve soil health. However, some farmers are hesitant to try these conservation practices due to uncertainty about whether planting winter cover crops will deplete soil moisture in already drought-stricken regions. Our study addresses these concerns by looking at how long-term reduced-disturbance tillage and winter cover cropping, compared to fallowed soils with standard tillage, affected soil moisture. Although we found a statistical difference in total soil water content, the difference was only about 0.3 inches of water per foot of soil. On average, the soil water content of the top 0–96 inches was highest for the reduced-disturbance fields with winter cover crops. This was especially evident during our driest field season, from November 1, 2017, to March 15, 2018, when cumulative rainfall was only 1.9 inches. Our findings show that winter cover cropping and reduced-disturbance tillage can improve soil without depleting soil water levels in row crops.

To meet the requirements of California's Sustainable Groundwater Management Act, there is a critical need for crop production strategies with less reliance on irrigation from surface and groundwater sources. One strategy for improving agricultural water use efficiency is reducing tillage and maintaining residues on the soil surface. We evaluated high residue no-till versus standard tillage in the San Joaquin Valley with and without cover crops on the yields of two crops, garbanzo and sorghum, for 4 years. The no-till treatment had no primary or secondary tillage. Sorghum yields were similar in no-till and standard tillage systems while no-till garbanzo yields matched or exceeded those of standard tillage, depending on the year. Cover crops had no effect on crop yields. Soil cover was highest under the no-till with cover crop system, averaging 97% versus 5% for the standard tillage without cover crop system. Our results suggest that garbanzos and sorghum can be grown under no-till practices in the San Joaquin Valley without loss of yield.

The Lancet Commission on Global Surgery (LCoGS) recommends using specialist surgical workforce density as one of 6 core indicators for monitoring universal access to safe, affordable surgical and anaesthesia care. Using Nepal as a case study, we explored the capacity of a generalist workforce (led by a family physician or MD general practitioner and non-physician anaesthetist) to enable effective surgical delivery through task-shifting. Using a multiple-methods approach, we retrospectively mapped essential surgical care and the enabling environment for surgery in 39 hospitals in 25 remote districts in Nepal and compared it with LCoGS indicators. All 25 districts performed surgery, 21 performed Caesarean section (CS), and 5 met at least 50% of district CS needs. Generalist surgical teams performed CS, the essential major operation at the district level, and very few laparotomies, but no operative orthopaedics. The density of specialist Surgeon/Anaesthesiologist/Obstetrician (SAO) was 0·4/100,000; that of Generalist teams (gSAO) led by a family physician (MD General Practitioners-MDGP) supported by non-physician anaesthetists was eight times higher at 3·1/100,000. gSAO presence was positively associated with a two-fold increase in CS availability. All surgical rates were well below LCoGS targets. 46% of hospitals had adequate enabling environments for surgery, 28% had functioning anaesthesia machines, and 75% had blood transfusion services. Despite very low SAO density, and often inadequate enabling environment, surgery can be done in remote districts. gSAO teams led by family physicians are providing essential surgery, with CS the commonest major operation. gSAO density is eight times higher than specialists and they can undertake more complex operations than just CS alone. These family physician-led functional teams are providing a pathway to effective surgical coverage in remote Nepal.

Floral scent (FS) plays a pivotal role in maintaining ecological equilibrium within plant populations and ecosystems while also bearing significance for human well-being. Despite the growing interest in FS research, there exists a dearth of comprehensive analyses on research trends, contemporary topics, and their broader implications. In this study, we employ bibliometric techniques using data from the Web of Science Core Collection spanning 1987–2022 to offer a quantitative overview of the scientific literature surrounding FS by examining the annual publication outputs, popular research areas, temporal trends in keywords, geographic distribution of relevant studies, institutions, co-organizations, as well as relevant authors. Our findings reveal a marked upsurge in FS publications, notably within the domains of Food Science Technology, Plant Sciences, Chemistry, Agriculture, Biochemistry, and Molecular Biology. The research landscape in FS primarily encompasses evolutionary dynamics, volatile compound analyses, biosynthesis mechanisms, and essential oil properties. These research trends signify a transition from micro-level exploration, focusing on individual pollination ecological functions of FS, to a macro-perspective that emphasizes FS’s overarching impact on species diversity and ecosystem stability. This shift extends from the investigation of singular sensory attributes of FS to a holistic evaluation of their role in food production, quality, and yield enhancement. It encompasses a move away from mere FS extraction towards the examination of antioxidant potential within phenolic compounds and other industrial applications. Thus, improving research methodologies, strengthening interdisciplinary collaboration on an international scale, and delving deeper into the multifaceted ecological functions of floral diversity and their societal implications will be paramount.

Clouded leopard (Neofelis nebulosa) is listed as vulnerable by the IUCN red list and is a protected species in Nepal. However, there is limited information on its status and distribution, which is a critical first step in conservation planning and management. To address this knowledge gap, this study attempts to: (a) predict the potential suitable habitat for the clouded leopard in Nepal with available occurrence point, (b) determine important variables (bioclimatic and environmental) responsible for its distribution and range limits, and (c) evaluate coverage of existing protected areas (PAs) in Nepal using MaxEnt modeling. The current model with a high discriminative ability (AUC = 0.945, TSS = 0.780) predicts 11,794 km2 suitable habitat for clouded leopard in Nepal, of which 72% of the area is distributed outside the current protected areas network of Nepal. Most of these habitats lie in the Middle mountain and Hilly regions, distributed from the Pachthar Ilam Taplejung corridor in the east to Annapurna Conservation Area in the mid-central part of Nepal. The most important variables responsible for its distribution were the mean Normalized Difference Vegetation Index (NDVI), Isothermality, and the precipitation of the coldest quarter associated with the forest cover landscape and climate. Deforestation and fragmentation of habitat and climate change in the Middle mountain and Hilly region, and occasional poaching are significant concerns, and may pose threats for the long-term conservation of this species. We recommend establishing community-based conservation areas in the Middle mountain and Hilly regions and investigating species distribution, status, and ecology, including its prey and habitat, across the Nepalese landscape. Identification of habitats and conservation opportunities is crucial for species' long-term conservation. Hence, the map produced here can serve as a reference for future investigations into clouded leopard distribution and could be a significant tool for formulating and implementing conservation strategies in Nepal.

While the importance of ecological conservation and encouraging public recreation in national parks is widely recognized, challenges to achieving these goals persist. With over a century of national park management experience, the institutional knowledge of national park systems in Australia, Canada, New Zealand, and the United States can offer a valuable insight into management best practices. Twelve open-ended semistructured interviews with national park experts representing the four systems revealed valuable lessons learned in major facets of national park management. Overall, our results suggest that effective and sustainable national park management requires federally-based organizational framework with deference to local institutions at park-level, stakeholder inclusion in park management decision-making, public engagement encouraged by information-sharing and education, clarity on boundaries to improve relations with adjacent land owners, and prioritizing improved indigenous relations. Interviews highlighted that better park governance is rooted in education to raise awareness of the importance of national parks and park systems to the public. Tourism and climate change were widely anticipated to increasingly pose challenges to park management, underscoring a shared urgency to address these issues.

Alkaliweed (Cressa truxillensis) is a native perennial plant of the western USA and in California, they are found primarily in saline and alkaline soils. Lately, it has been observed in Central Valley pistachio, olive, and almond orchards as a problematic species. Very little information is available on the effect of environmental factors on germination, shade tolerance, and the response of this species to herbicides. Therefore, studies were conducted to assess the effect of environmental factors (water potential, salinity, and pH) on seed germination, the influence of shade (30% shade 70% shade, and no shade) on aboveground growth, and the response of alkaliweed to common registered post-emergent herbicides. Results showed that the seeds were moderately tolerant to drought but highly adapted to salinity and pH as germination occurred up to an electrical conductivity level of 20 dS m−1 and pH range of 5 to 9. Both shade levels reduced aboveground growth and formation of reproductive structures. None of the postemergence herbicides provided adequate control of the plants. Therefore, an integrated management plan needs to be developed for alkaliweed control in Central Valley orchards.

Introduction: The most common fusion anomaly, horseshoe kidney, is associated with vascular anomalies, malrotation, anterior displacement of the collecting system, superior insertion of ureter into the pelvis, and a higher rate of ureteropelvic junction obstruction; thus increasing the chances of nephrolithiasis. We present our experience with percutaneous nephrolithotomy in this anomaly. Materials and Methods: A retrospective study of all the percutaneous nephrolithotomy performed by standard technique within four years at Bir Hospital was made. A comparison was made with similar cases with the anatomically normal location of the kidney. Intraoperative variables were recorded and postoperative stonefree status and complications were evaluated. Results: Six hundred and twenty-seven patients out of 691 who had undergone percutaneous nephrolithotomy in this period were included. Patients with nephrolithiasis in horseshoe kidney were younger, the incidence of multiple stones was more; without full staghorn calculus and occupying fewer calyces. Upper pole access was easier, a stone clearance of 85.42 % was achieved with no major complications in the horseshoe kidney. Conclusions: Percutaneous access and nephrolithotomy are safe in horseshoe kidney with a good stone clearance rate.

Introduction: To evaluate if retrograde intrarenal surgery with ureteral access sheath requires prestenting. In case pre-stenting becomes an option, how long does it need to be stented. Materials and Methods: After obtaining approval from Institutional Review Board and informed consent, a prospective randomized controlled study was conducted in the Department of Urology, Bir Hospital for 18 months. All the patients enrolled for retrograde intrarenal surgery were grouped into 3 groups: Group 1 – without pre-stenting, Group 2 – one week of pre-stenting, and Group 3 – two weeks of pre-stenting. Success was defi ned as an ability to accommodate a 10/12 F ureteral access sheath during retrograde intrarenal surgery. Ureteral access sheath induced ureteric wall injury was also taken into consideration. Results: Among 179 cases, 152 cases were included in the study. In 36 patients out of 53 (67.92%) in group 1, 10/12 F ureteral access sheath was negotiable without pre-stenting, marking the frequency of distensible ureters. In 44 patients out of 47 (93.66%) from group 2 and all 52 patients (100%) from group 3, ureteral access sheath placement was successful after one and two weeks of pre-stenting respectively. Ureteric wall injury of grade1 and 2, was found in 9 patients (5.9%). Conclusions: The majority of ureters (67.92%) are distensible, not requiring pre-stenting before retrograde intrarenal surgery. One and two weeks of pre-stenting carries a success rate of 93.66% and 100% respectively.

Introduction: Fluoroscopic guidance is routine for endourological procedures like percutaneous nephrolithotomy and retrograde intrarenal surgery in vast majority of centers. It is used for the initial retrograde ureteral access to define the pelvicalyceal system, puncture of the desired calyx and dilatation of the tract, aid navigation of stones and calyces, and placement of guide wires and stents. Both the patient and operating staffs are exposed to the radiation during surgery. The purpose of this study is to measure that exposed fluoroscopic radiation dose during these procedures and make operating surgeons aware of their fluoroscopic habit. Materials and Methods: This is prospective observational study, who underwent percutaneous nephrolithotomy (n=60) and retrograde intrarenal surgery (n=43) in our institute between December 2017 and August 2018. Percutaneous nephrolithotomy was done in prone position with prior insertion of ureteric catheter. Retrograde intrarenal surgery was carried out with or without insertion of ureteral access sheath. Fluoroscopic time was taken from the insertion of the ureteric catheter or UAS to the completion of the procedure with double J stenting. Results: For percutaneous nephrolithotomy and retrograde intrarenal surgery group, mean stone size were 21.89 mm and 10.56 mm; mean fluoroscopic time were 117.95 s (range 24-350) and 31.83 s (range 3-103); mean fluoroscopic dose were 29.71 mGy and 6.19 mGy respectively. Introduction: Fluoroscopic guidance is routine for endourological procedures like percutaneous nephrolithotomy and retrograde intrarenal surgery in vast majority of centers. It is used for the initial retrograde ureteral access to define the pelvicalyceal system, puncture of the desired calyx and dilatation of the tract, aid navigation of stones and calyces, and placement of guide wires and stents. Both the patient and operating staffs are exposed to the radiation during surgery. The purpose of this study is to measure that exposed fluoroscopic radiation dose during these procedures and make operating surgeons aware of their fluoroscopic habit. Materials and Methods: This is prospective observational study, who underwent percutaneous nephrolithotomy (n=60) and retrograde intrarenal surgery (n=43) in our institute between December 2017 and August 2018. Percutaneous nephrolithotomy was done in prone position with prior insertion of ureteric catheter. Retrograde intrarenal surgery was carried out with or without insertion of ureteral access sheath. Fluoroscopic time was taken from the insertion of the ureteric catheter or UAS to the completion of the procedure with double J stenting. Results: For percutaneous nephrolithotomy and retrograde intrarenal surgery group, mean stone size were 21.89 mm and 10.56 mm; mean fluoroscopic time were 117.95 s (range 24-350) and 31.83 s (range 3-103); mean fluoroscopic dose were 29.71 mGy and 6.19 mGy respectively. Conclusions: Among the endourological procedures for renal stones, retrograde intrarenal surgery was associated with less fluoroscopic hazard than percutaneous nephrolithotomy. Awareness of fluoroscopic exposure duration and experience of a surgeon can minimize the radiation hazard during endourological procedures.

Human–wildlife conflict is a challenging issue that requires the attention of conservationists worldwide. Habitat fragmentation and encroachment reduce the abundance of prey species, and an increase in the number of predators leads to a higher risk of conflict with large cats such as leopards, jeopardizing conservation efforts. This study explored the spatio-temporal pattern of the human–leopard conflict in Bardia National Park, Nepal, from 2000 to 2020. To analyze the conflict with leopards, we used data (compensation cases filed in the park) from the buffer zone management office, the National Trust for Nature Conservation (NTNC), and the Department of National Park and Wildlife Conservation (DNPWC). Leopard attacks on livestock are increasing exponentially, with 3335 livestock killed in 2652 attacks occurring during the study period. Although livestock depredation by leopards occurred all over the park, the southern cluster has most documented livestock damage (64.01%). The eastern and northern clusters reported fluctuating and dispersed predation events, respectively. Our spatial analysis indicated no effect of topography (slope) on livestock depredation by leopards. We recorded the highest number of leopard attacks and predation during the dry winter season when the nights are longer and livestock remain in their sheds. This carnivore mostly limited its prey to small-sized livestock (95.77%) such as goats, sheep, and pigs, whereas attacks on large-sized (cow and buffalo) livestock were least frequent. Among small-sized livestock, goats are the most predated (66.92%), followed by pigs (20.30%), in all seasons. The escalating human–leopard conflict in BNP is thus a severe threat to conservation efforts as the park has already invested a substantial amount of money (approx. USD 80,000) compensating for livestock lost in leopard attacks over the last two decades. Improving habitat conditions to reduce competition inside the park, developing an insurance scheme for livestock and humans, providing support for upgraded sheds, and the development of practical and feasible strategies that focus on specific animals and clusters of the national park are needed to reduce conflicts to maintain the co-existence between wildlife and human beings.

BackgroundClear cell adenocarcinoma (CCA) is considered a relatively rare tumor with a glycogen-rich phenotype. The prognosis of CCA patients is unclear. In this study, recent trends in the epidemiological and prognostic factors of CCA were comprehensively investigated.MethodsPatients with CCA from years 2000 to 2016 were identified from the Surveillance, Epidemiological, and End Results (SEER) database. Relevant population data were used to analyze the rates age-adjusted incidence, age-standardized 3-year and 5-year relative survivals, and overall survival (OS).ResultsThe age-adjusted incidence of CCA increased 2.7-fold from the year 2000 (3.3/100,000) to 2016 (8.8/100,000). This increase occurred across all ages, races, stages, and grades. Of all these subgroups, the increase was largest in the grade IV group. The age-standardized 3-year and 5-year relative survivals increased during this study period, rising by 9.1% and 9.5% from 2000 to 2011, respectively. Among all the stages and grades, the relative survival increase was greatest in the grade IV group. According to multivariate analysis of all CCA patients, predictors of OS were: age, gender, year of diagnosis, marital status, race, grade, stage, and primary tumor site (P < 0.001). The OS of all CCA patients during the period 2008 to 2016 was significantly higher than that from 2000 to 2007 (P < 0.001).ConclusionsThe incidence of CCA and survival of these patients improved over time. In particular, the highest increases were reported for grade IV CCA, which may be due to an earlier diagnosis and improved treatment.

Cover crops are an important component of integrated weed management programs in annual and perennial cropping systems because of their weed suppressive abilities. They influence weed populations using different mechanisms of plant interaction which can be facilitative or suppressive. However, the question often arises if cover crops can be solely relied upon for weed management or not. In this review we have tried to provide examples to answer this question. The most common methods of weed suppression by an actively growing cover crop include competition for limited plant growth resources that result in reduced weed biomass, seed production, and hence reductions in the addition of seeds to the soil seedbank. Cover crop mulches suppress weeds by reducing weed seedling emergence through allelopathic effects or physical effects of shading. However, there is a great degree of variability in the success or failure of cover crops in suppressing weeds that are influenced by the cover crop species, time of planting, cover crop densities and biomass, time of cover crop termination, the cash crop following in the rotation, and the season associated with several climatic variables. Several studies demonstrated that planting date was important to achieve maximum cover crop biomass, and a mixture of cover crop species was better than single cover crop species to achieve good weed suppression. Most of the studies that have demonstrated success in weed suppression have only shown partial success and not total success in weed suppression. Therefore, cover crops as a sole tool may not be sufficient to reduce weeds and need to be supplemented with other weed management tools. Nevertheless, cover crops are an important component of the toolbox for integrated weed management.

Background and Aims: Intraperitoneal instillation of local anaesthetics has been shown to minimise post-operative pain after laparoscopic surgery. This study was aimed to evaluate the post-operative effect of intraperitoneal ropivacaine with and without tramadol in patients undergoing laparoscopic cholecystectomy. Methods: Eighty patients undergoing laparoscopic cholecystectomy were randomised into two groups. Group R received 0.5% ropivacaine 18 mL with normal saline (NS) 2 mL and Group RT received 0.5% ropivacaine 18 mL with tramadol (100 mg, 2 mL) at the end of surgery intraperitoneally through the port. The pain score was monitored using a numerical rating scale (NRS) every 30 min till 4 h post-operatively and then at 6 h, 12 h and 24 h. The primary objective of the study was to compare the severity of pain between the groups. The secondary objectives were to compare the total dose of rescue analgesic and the time to first rescue analgesia between the groups Statistical analysis was performed using statistical package for the social sciences. Chi-square test and Mann Whitney U test were used for analysis. Results: The pain score in Group RT was significantly lower than Group R at 2.5 h to 24 h (P = 0.005). Only 42.5% in Group RT demanded rescue analgesia as compared to 75% in Group R (P = 0.003). Total analgesic consumption of fentanyl was also reduced in the tramadol group (785 μg vs 1800 μg). No significant adverse effects were found. Conclusion: Intraperitoneal instillation of ropivacaine with tramadol reduces the post-operative pain and analgesic requirement in laparoscopic cholecystectomy as compared to ropivacaine alone.

Abstract Background The World Health Organization (WHO) End TB Strategy has established a milestone to reduce the number of tuberculosis (TB)- affected households facing catastrophic costs to zero by 2020. The role of active case finding (ACF) in reducing patient costs has not been determined globally. This study therefore aimed to compare costs incurred by TB patients diagnosed through ACF and passive case finding (PCF), and to determine the prevalence and intensity of patient-incurred catastrophic costs in Nepal. Methods The study was conducted in two districts of Nepal: Bardiya and Pyuthan (Province No. 5) between June and August 2018. One hundred patients were included in this study in a 1:1 ratio (PCF: ACF, 25 consecutive ACF and 25 consecutive PCF patients in each district). The WHO TB patient costing tool was applied to collect information from patients or a member of their family regarding indirect and direct medical and non-medical costs. Catastrophic costs were calculated based on the proportion of patients with total costs exceeding 20% of their annual household income. The intensity of catastrophic costs was calculated using the positive overshoot method. The chi-square and Wilcoxon-Mann-Whitney tests were used to compare proportions and costs. Meanwhile, the Mantel Haenszel test was performed to assess the association between catastrophic costs and type of diagnosis. Results Ninety-nine patients were interviewed (50 ACF and 49 PCF). Patients diagnosed through ACF incurred lower costs during the pre-treatment period (direct medical: USD 14 vs USD 32, P = 0.001; direct non-medical: USD 3 vs USD 10, P = 0.004; indirect, time loss: USD 4 vs USD 13, P

Qilian Mountain National Park (QLMNP) is a biodiversity hotspot with great agriculture and tourism resources. With the expansion of human activities, a few areas of the park are experiencing massive landscape transformation, and these areas are also highly ecologically sensitive. Nevertheless, there are substantial differences in the human activities and natural resources of various communities around QLMNP, resulting in heterogeneous landscape degradation. Hence, this study explores the extent and drivers of spatial heterogeneity in landscape fragmentation associated with ecologically vulnerable communities in QLMNP. Multiple ring buffer analysis and geographically weighted regression (GWR) were used to analyze the relationships between landscape fragmentation and variables of human activities and facilities to identify the main factors influencing landscape fragmentation in different regions. The results reveal that human disturbance had a stronger relationship with landscape fragmentation in QLMNP than natural factors do. Among the drivers of landscape fragmentation, the distribution of residential areas and the extension of agricultural land were found to have more significant impacts than tourism. Expansion of cropland had a greater impact on the eastern part of the national park, where overgrazing and farming require further regulation, while tourism affected the landscape fragmentation in the central area of the national park. The point-shaped human disturbance had a larger impact than the linear disturbance. The study findings can be used to formulate a comprehensive plan to determine the extent to which agriculture and tourism should be developed to avoid excessive damage to the ecosystem.

Background: Emphysematous pyelonephritis (EPN) is a necrotizing infection of the kidney and surrounding tissues with significant mortality. We aimed to assess the clinical factors and their influence on prognosis in patients being managed for EPN with and without ESBL-producing bacteria and to identify if those with EPN due to ESBL infections fared any different. Methods: A retrospective analysis was performed on patients with EPN diagnosis from 22 centers across 11 countries (between 2013 and 2020). Demographics, clinical presentation, biochemical parameters, radiological features, microbiological characteristics, and therapeutic management were assessed. Univariable and multivariable analyses were performed to determine the independent variables associated with ESBL pathogens. A comparison of ESBL and non-ESBL mortality was performed evaluating treatment modality. Results: A total of 570 patients were included. Median (IQR) age was 57 (47–65) years. Among urine cultures, the most common isolated pathogen was Escherichia coli (62.2%). ESBL-producing agents were present in 291/556 urine cultures (52.3%). In multivariable analysis, thrombocytopenia (OR 1.616 95% CI 1.081–2.413, p = 0.019), and Huang–Tseng type 4 (OR 1.948 95% CI 1.005–3.778, p= 0.048) were independent predictors of ESBL pathogens. Patients with Huang–Tseng Scale type 1 had 55% less chance of having ESBL-producing pathogens (OR 1.616 95% CI 1.081–2.413, p = 0.019). Early nephrectomy (OR 2.3, p = 0.029) and delayed nephrectomy (OR 2.4, p = 0.015) were associated with increased mortality in patients with ESBL infections. Conservative/minimally invasive management reported an inverse association with mortality (OR 0.314, p = 0.001). Conclusions: ESBL bacteria in EPN were not significantly associated with mortality in EPN. However, ESBL infections were associated with poor prognosis when patients underwent nephrectomy compared conservative/minimally invasive management.

Background: Transversus abdominis plane block is a valuable component of multimodal analgesia regimen. Magnesium sulphate has been shown to increase the duration of action of different peripheral nerve blocks. We assessed the efficacy of magnesium sulphate as an adjuvant to bupivacaine in transversus abdominis plane block in patients scheduled for total abdominal hysterectomy under general anaesthesia. Methods: Sixty-six patients undergoing total abdominal hysterectomy under general anaesthesia were divided into two groups. Ultrasound-guided bilateral transversus abdominis plane block was performed in both groups before extubation. Bupivacaine alone group received block with 20ml of 0.25% bupivacaine while Bupivacaine with Magnesium group received block with 20ml of 0.25% bupivacaine with 150mg of magnesium sulphate on each side. Pain scores at 0, 2, 4, 6, 12, and 24 hours postoperatively along with time to first request of analgesia, total consumption of fentanyl, and incidence of nausea or vomiting were noted. Results: Group BM showed significantly lower pain scores at 4 and 6 hours (p=0.001 and 0.017 respectively). Time to first request of analgesia was significantly more in Group BM [285 minutes (85, 370) vs. 75 minutes (52.5, 150), (p

Introduction: Percutaneous nephrolithotomy has the highest stone free rate among other procedures with relatively higher complication rate. Post-operative imaging after stone surgeries has not been uniform. This study was done to study about the stone clearance by computed tomography after percutaneous nephrolithotomy. Methods: The descriptive cross-sectional study was conducted in the Department of Urology, Bir Hospital for six months duration. The patients undergoing percutaneous nephrolithotomy and those with intra-operative fluoroscopic clearance were evaluated with a low dose computed tomography after 48 hours to assess residual fragments its size and location. Patient’s demographics, stone characteristics and complications were compared between the stone free and with residual stone patients. Results: Out of 72 percutaneous nephrolithotomy performed, 40 patients were included in the study. Low dose computed tomography kidney, ureter and bladder after 48 hours of surgery detected residual fragments in 11 (27.5%) patients. The RFs size of 4mm were found in 4 (36.36%). The stone size was 352.47 ± 97.47 mm2 and 254.79 ± 172.68mm2 in group with residual fragments and stone free group respectively. Conclusions: Low dose computed tomography kidney, ureter and bladder done for assessment of stone clearance after 48 hours of percutaneous nephrolithomy detected residual in around one fourth of patients, however majority of them had residual fragments 4mm size.

Abstract Objective Neonatal sepsis is a major cause of morbidity and mortality of newborns (

Abstract Background Avian pathogenic Escherichia coli (APEC) are causative agent of extraintestinal infections, collectively known as colibacillosis, which results significant losses in poultry industries. The extraintestinal survival of E. coli is facilitated by numerous virulence factors which are coded by virulence genes. This study was conducted to find out the pattern of antibiotic resistance and virulence genes content in the APEC strains isolated from broiler chickens at National Avian Disease Investigation Laboratory and Veterinary Teaching Hospital, Rampur, Chitwan, Nepal. Results A total of 50 E. coli strains were isolated from 50 colibacillosis suspected broiler chickens. Out of 50 isolates of E. coli, 47 (94%) showed resistant to three or more antimicrobials. The highest levels (22%) of multidrug-resistant E. coli were observed for five different types of antimicrobials. Antibiogram profiles of 50 E. coli strains showed the maximum resistance to ampicillin (98%), followed by co-trimoxazole (90%), and doxycycline (62%). The highest intermediate resistance was shown by colistin (50%) and the highest sensitivity was against amikacin (84%), followed by nitrofurantoin (55%). Based on the genetic criteria, 45 (90%) E. coli isolates were considered as pathogenic (APEC) which contained more than five virulence genes. Out of total APEC genes detected, we found the combination of iss, iucD, hlyF, ompT, iroN, and iutA genes were mostly associated with the APEC and additionally, to some lesser extent irp2, papC, Cva/cvi, and tsh genes showed the critical role for virulent traits of APEC strains. Conclusion In this study, high prevalent of antimicrobial resistant pattern was found with avian pathogenic E. coli strains isolated from broiler chickens. To our knowledge, this is the first molecular analysis which confirmed the prevalence of APEC strains in poultry sector in Nepal. These finding suggest the need of surveillance and intervention system to control misuse of antibiotics and APEC outbreak in the poultry farm.

Abstract Objective Multidrug resistance (MDR) and extended spectrum beta lactamase (ESBL) producer Gram negative bacteria are considered as a major health problem, globally. ESBL enzyme hydrolyses the beta lactam ring of third generation cephalosporins, which alters the structure of the antibiotic. Due to the modification in structure of the antibiotic, bacteria show resistance to these antibiotics. Resistant bacterial strains are transmitted to humans from animals through consumption of uncooked meat, through contact with uncooked meat and meat surfaces. This study aims to assess bacteriological profile and analyze the situation of antibiotic resistance, multidrug resistance, and ESBL producing Gram negative bacteria in chicken meat. Results A total of 38 chicken meat samples were studied in which 103 Gram negative bacteria were isolated. Species of Gram negative bacteria were identified as Citrobacter spp. (44.7%), Salmonella spp. (26.2%), Proteus spp. (18.4%), Escherichia coli (4.8%), Shigella spp. (3.9%), Pseudomonas spp. (1.9%), and Klebsiella spp. (1.0%). The prevalence of MDR isolates was found to be 79.6%. Total ESBL producer was 36.9% and ESBL producer among MDR was 34.9%. This concludes wide range of antibiotic resistance bacteria is prevalent in raw chicken meat.

Salinas Valley lettuce growers are adopting automated lettuce thinners to improve labor efficiency. We conducted field studies in 2014 and 2015 to compare the time involved in automated and manual thinning of direct-seeded lettuce and any differences in lettuce quality and yield. We recorded the number of doubles (two closely spaced plants) left behind after thinning, time taken to remove the doubles, final crop stand, efficiency in weed removal, crop yield and disease incidence. Using an automated thinner in place of manual hoeing reduced the thinning labor requirement from 7.31 person-hours per acre to 2.03 person-hours per acre. Automated thinning left more doubles than manual thinning, resulting in additional time to remove them, but was overall more labor-efficient and had no impact on yield or disease incidence.

Cyanobacteria, are only Gram-negative bacteria with the capacity of oxygenic photosynthesis, so termed as “Cyanophyta” or “blue-green algae.” Their habitat is ubiquitous, which includes the diverse environments, such as soil, water, rock and other organisms (symbiosis, commensalism, or parasitism, etc.,). They are characterized as prominent producers of numerous types of important compounds with anti-microbial, anti-viral, anti-inflammatory and anti-tumor properties. Among the various cyanobacterial genera, members belonging to genera Nostoc, Lyngbya, and Microcystis possess greater attention. The major reason for that is the strains belonging to these genera produce the compounds with diverse activities/structures, including compounds in preclinical and/or clinical trials (cryptophycin and curacin), or the compounds retaining unique activities such as protease inhibitor (micropeptins and aeruginosins). Most of these compounds were tested for their efficacy and mechanism of action(MOA) through in vitro and/or in vivo studies. Recently, the advances in culture techniques of these cyanobacteria, and isolation, purification, and chromatographic analysis of their compounds have revealed insurmountable novel bioactive compounds from these cyanobacteria. This review provides comprehensive update on the origin, isolation and purification methods, chemical structures and biological activities of the major compounds from Nostoc, Lyngbya, and Microcystis. In addition, multi-omics approaches and biotechnological production of compounds from selected cyanobacterial genera have been discussed.

Crop production is a constant battle with weeds, in which weeds, generally, are victorious. Therefore, rather than channeling our efforts into the development of a “silver bullet” to control weeds, the focus should be on sustainable weed management in both natural- and agro-ecosystems. However, sustainable weed management can be a challenge in the context of global climate change. Over the past few decades, global climate change, mostly indicated by phenomena such as increased atmospheric temperature and elevated CO2 levels, is evident due to human activities and natural events. These phenomena also affect regional/local climate, resulting in significant influences on the agricultural systems of a particular region. Rising CO2 levels may give comparative advantages to C3 plants through increased photosynthesis, biomass production and yield, compared to C4 plants. Plants with C4 photosynthetic pathways, on the other hand, are likely to benefit more from rising global temperatures than C3 plants. Thus, the differential responses of C3 and C4 plants to climate change may alter crop–weed interactions and competition outcomes, most likely at the expense of the crop. Climate change will likely cause shifts in weed community compositions, their population dynamics, life cycle, phenology, and infestation pressure. Some weed species may go extinct, while some others may become more aggressive invaders. Weeds are, generally, colonizers and have some unique biological traits and ecological amplitudes that enable them to successfully dominate crops in a habitat with changed environmental conditions. Moreover, climate shifts, especially erratic rainfall and drought, may affect herbicide selectivity and efficacy or the success of bio-control agents resulting in an establishment of a mixed and complex population of C3 and C4 weed species adding to the complexity of weed management. Although elevated CO2 levels will stimulate the productivity of major C3 crops, most troublesome agricultural weeds will likely be more responsive to a rise in CO2 than crops, and thus may dominate the agro-ecosystem. It is predicted that, as temperature rises, the majority of the C4 weeds will flourish and will pose serious crop yield losses. Understanding and assessment of the impact of simultaneous changes in multiple climate factors and their complex interactions on crops and weeds are therefore necessary to formulate an adaptive weed management approach and build resilience. Moreover, strategic policies and strong actions need to be taken to reduce the root causes of CO2 and other greenhouse gas emissions to minimize the impact of climate change on weed biology and management.

This study compared the yield of tuberculosis (TB) active case finding (ACF) interventions applied under TB REACH funding. Between June 2017 to November 2018, Birat Nepal Medical Trust identified presumptive cases using simple verbal screening from three interventions: door-to-door screening of social contacts of known index cases, TB camps in remote areas, and screening for hospital out-patient department (OPD) attendees. Symptomatic individuals were then tested using smear microscopy or GeneXpert MTB/RIF as first diagnostic test. Yield rates were compared for each intervention and diagnostic method. We evaluated additional cases notified from ACF interventions by comparing case notifications of the intervention and control districts using standard TB REACH methodology. The project identified 1092 TB cases. The highest yield was obtained from OPD screening at hospitals (n = 566/1092; 52%). The proportion of positive tests using GeneXpert (5.5%, n = 859/15,637) was significantly higher than from microscopy testing 2% (n = 120/6309). (OR = 1.4; 95%CI = 1.12–1.72; p = 0.0026). The project achieved 29% additionality in case notifications in the intervention districts demonstrating that GeneXpert achieved substantially higher case-finding yields. Therefore, to increase national case notification for TB, Nepal should integrate OPD screening using GeneXpert testing in every district hospital and scale up of community-based ACF of TB patient contacts nationally.

Purpose: This study aimed to compare the safety and efficacy of tamsulosin and tadalafil as medical expulsive therapy for distal ureteral stones. Materials and Methods: This prospective randomized study was conducted at the Department of Urology of Bir Hospital over a period of 12 months in patients with distal ureteral stones sized 5 to 10 mm. Patients were randomly divided into 2 groups: group A received tamsulosin 0.4 mg and group B received tadalafil 10 mg at bedtime for 2 weeks. Stone expulsion rate, number of ureteric colic episodes and pain score, analgesic requirements, and adverse drug effects were noted in both groups. Statistical analyses were performed by using Student t-test and chi-square test. Results: Altogether 85 patients, 41 in group A and 44 in group B, were enrolled in the study. The patients’ average age was 31.72±12.63 years, and the male-to-female ratio was 1.5:1. Demographic profiles, stone size, and baseline investigations were comparable between the 2 groups. The stone expulsion rate was significantly higher in the tadalafil group than in the tamsulosin group (84.1% vs. 61.0%, p=0.017). Although the occurrence of side effects was higher with tadalafil, this difference was not significant (p=0.099). There were no serious adverse effects. Conclusions: Tadalafil has a significantly higher stone expulsion rate than tamsulosin when used as a medical expulsive therapy for distal ureteral stones sized 5–10 mm. Both drugs are safe, effective, and well tolerated with minor side effects.

Overhead systems are the dominant irrigation technology in many parts of the world, but they are not widely used in California even though they have higher water application efficiency than furrow irrigation systems and lower labor requirements than drip systems. With water and labor perennial concerns in California, the suitability of overhead systems merits consideration. From 2008 through 2013, in studies near Five Points, California, we evaluated overhead irrigation for wheat, corn, cotton, tomato, onion and broccoli as an alternative to furrow and drip irrigation. With the exception of tomato, equal or increased yields were achieved with overhead irrigation. Many variables are involved in the choice of an irrigation system, but our results suggest that, with more research to support best management practices, overhead irrigation may be useful to a wider set of California farmers than currently use it.

In recent years, spread of invasive alien plant species (IAPS) has been a major concern in Nepal. One such IAPS is Ageratum houstonianum, an Asteraceae, that is a prolific seed producer and difficult-to-control in farmland and various ecological regions causing crop yield and biodiversity losses. However, very little information is available on the germination biology and ecology of this species. Therefore, experiments were conducted to assess the effect of water stress, pH level, and light requirement on seed germination, and the effect of seed burial depth on seedling emergence. Water stress was simulated by polyethylene glycol solutions ranging from 0-5.56 MPa and pH solutions ranging from 4 to 9 were prepared using hydrochloric acid and sodium hydroxide. Germination tests were conducted in petri dishes lined with filter paper and placed in a controlled environment chamber set at 20° C. Light requirement comparisons were made by having petri dishes wrapped with aluminum foil or left unwrapped. Seedling emergence was evaluated by placing seeds at depths ranging from 0 to 20 mm in the soil. Results indicated that this species was moderately drought-tolerant because germination ceased beyond 0.51 MPa. Greater germination occurred at neutral to acidic than at alkaline pH levels. The seeds were positively photoblastic because no germination occurred under dark condition. No seedlings emerged from seeds placed more than 2 mm deep in the soil, indicating that this is a primarily surface germinating species. These findings will help predict future invasions and in development of management strategies for this IAPS.

BackgroundWhile Nepal's maternal mortality ratio (MMR) has improved overall, the proportion of maternal deaths occurring in health facilities and attended to by skilled birth attendants (SBAs), has nearly doubled over 12 years. Although there are numerous socioeconomic, environmental and other factors at play, one possible explanation for this discrepancy between utilization of skilled maternal care services and birth outcomes lies in the quality of care being provided by SBAs. The objective of this study is to determine how competent SBAs are after training, across multiple settings and facility types in Nepal.MethodsWe used a quantitative cross-sectional analysis to evaluate a sample of 511 SBAs, all female, from 276 sub-health posts (SHP), health posts (HP), primary healthcare centers (PHC), and district and regional hospitals in the mountain, hill, and terai districts of Nepal. Any SBA actively employed by one of these health facilities was included. SBAs who had received less than three months of training were excluded. Outcomes were measured using SBAs' scores on a standardized knowledge assessment, clinical skills assessment, and monthly delivery volume, particularly as it compared with the WHO's recommendation for minimum monthly volume to maintain competence.ResultsSBAs on average exhibit a deficiency of both knowledge and clinical skills, failing to meet even the 80-percent standard that is required to pass training (knowledge: 75%, standard deviation 12%; clinical skills: 48%, standard deviation 15%). Moreover, SBAs are conducting very few deliveries, with only 7 percent (38/511) meeting the minimal volume recommended to maintain competence by the WHO, and a substantial fraction (70/511, 14%) performing an average of no monthly deliveries at all.ConclusionsTaken together, our findings suggest that while countries like Nepal have made important investments in SBA programs, these healthcare workers are failing to receive either effective training or sufficient practice to stay clinically competent and knowledgeable in the field. This could in part explain why institutional deliveries have generally failed to deliver better outcomes for pregnant women and their babies.

Introduction: Dilation of the track can be achieved by multiple incremental flexible Amplatz type, Alken metal telescoping dilators, or balloon in Percutaneous Nephrolithotomy (PCNL). Balloon dilator is the most expensive method. Both of the incremental dilation techniques are more time consuming with higher failure rates. Hence, a prospective randomized study was conducted to compare the safety and efficacy of “single shot” dilation of the nephrostomy tract by amplatz dilator with serial alken metallic telescopic dilation technique in PCNL. Methods: Of the 138 renal stone patients who underwent PCNL from January 2015 to December 2015, 100 patients were randomized into two groups. Serial tract dilation with alken metallic dilators was used in group A (n=50), and one shot dilation technique in Group B (n=50). The access tract dilation time, success rate, blood loss and complications were evaluated. Results: Both the groups were comparable in terms of mean age, location and size (largest diameter) of the stone (p>0.05). No difference was observed in the procedural success rate between groups A and B (96% v 94% respectively, p=0.64). Mean access time was similar in both groups (5.89+2.67 vs 4.98+2.0 mins, p=0.06). Complications between the groups were not significantly different. There were 6 patients with previous open stone surgery in both the groups. Previous open stone surgery did not impact procedural success rate, access time and complications in both groups. Conclusion: One-shot dilation technique is equally as effective, safe and well tolerated as metal telescopic dilation techniques even in patients with history of ipsilateral open stone surgery.

Invasive and endemic weeds pose recurring challenges for California land managers. The evolution of herbicide resistance in several species has imposed new challenges in some cropping systems, and these issues are being addressed by UC Cooperative Extension farm advisors, specialists and faculty. There are currently 24 unique herbicide-resistant weed biotypes in the state, dominated by grasses and sedges in flooded rice systems and, more recently, glyphosate-resistant broadleaf and grass weeds in tree and vine systems, roadsides and glyphosate-tolerant field crops. Weed scientists address these complex issues using approaches ranging from basic physiology and genetics research to applied research and extension efforts in grower fields throughout the state. Although solutions to herbicide resistance are not simple and are affected by many biological, economic, regulatory and social factors, California stakeholders need information, training and solutions to address new weed management problems as they arise. Coordinated efforts conducted under the Endemic and Invasive Pests and Disease Strategic Initiative directly address weed management challenges in California's agricultural industries.

Cotton production in the San Joaquin Valley has traditionally relied heavily on tillage for its presumed benefits to plant establishment, yields and insect management. Research in the 1960s and 1970s demonstrated the potential of precision or zone tillage, which foreshadowed the introduction of a variety of minimum tillage implements in the early 1990s. During a 3-year comparison study from 2001 to 2003, cotton yields in strip tillage plots matched or exceeded yields of standard tillage plots in all 3 years. In a 12-year study from 1999 to 2011, tillage costs were lowered an average of $70 per acre in 2011 dollars using no-tillage compared to standard tillage while achieving statistically comparable yields, provided that adequate crop stands were achieved. If bottom-line profitability can be maintained, conservation tillage may become increasingly attractive to cotton producers in the San Joaquin Valley.

Groundwater nitrate contamination in the Central Valley (CV) aquifer of California is widespread throughout the valley because of excess nitrogen fertilizer leaching down into the aquifer. The percolation of nitrate depends on several hydrogeological conditions of the valley. Groundwater contamination vulnerability mapping uses hydrogeologic conditions to predict vulnerable areas. This paper presents a new Geodetector-based Frequency Ratio (GFR) method and an optimized-DRASTIC method to generate nitrate vulnerability index values for the CV. The optimized-DRASTIC method combined the individual weights and rating values for Depth to water, Recharge rate, Aquifer media, Soil media, Topography, Impact of vadose zone, and Hydraulic conductivity. The GFR method incorporated the Frequency-Ratio (FR) method to derive rating values and the Geodetector method to derive relative Power of Determinant (PD) values as weights to generate nitrate susceptibility index map. The optimized-DRASTIC method generated very-high to high index values in the eastern part of the CV. The GFR method showed very-high index values in most part of the San Joaquin and Tulare basin. The quantitatively derived rating values and weights in the GFR method improved the vulnerability index and showed better consistency with the observed nitrate contamination pattern than optimized-DRASTIC index, suggesting that GFR is a better method for groundwater contamination vulnerability mapping in the CV aquifer.

In recent years, growers and pest consultants have reported poor control of the weed hairy fleabane in some areas of the Central Valley. Hairy fleabane seeds were collected from Esparto, Fresno and Reedley, Calif., and greenhouse-grown seedlings were treated at several different glyphosate rates and compared with an untreated control. None of the Esparto or Fresno plants survived glyphosate rates greater than 0.78 pounds acid equivalent per acre (lb ae/ac), while some of the plants from Reedley survived even the highest rate of glyphosate tested (12.4 lb ae/ac). The dose required to reduce plant dry weights by 50% (GR50) of the Esparto plants ranged from 0.28 to 0.30 lb ae/ac, whereas the GR50 of the Fresno and Reedley plants ranged from 0.26 to 0.61 and 0.92 to 2.88 lb ae/ac, respectively. This study showed that the hairy fleabane plants from Reedley were much more tolerant of glyphosate than either of the other two biotypes and, based on the GR50, the level of resistance ranged from 3-to 10-fold greater.

Conservation tillage (CT) systems have a number of potential benefits including lower crop production costs and the ability to reduce soil erosion that have made them common in several regions of the world. Although CT systems have been researched and successfully implemented on some farms in California's San Joaquin Valley (SJV), overall adoption is low and the reasons for the region's comparatively low rates of adoption are not known. In 2011, we conducted written surveys and interviews with SJV farmers to identify characteristics of farmers who adopt or do not adopt CT, to determine reasons for non-adoption of CT, and to learn how successful CT adoption takes place in the SJV. We found that a universally acceptable definition of CT needs to be developed in order for effective research, outreach and communication on CT. Our research, which examined CT adoption within the expected progression of the diffusion of innovation model, suggested that larger and less diverse farms were more likely to use CT. Most farmers expressed transition to CT as a continuous learning process. Further, we conclude that gaining meaningful experience with CT practices by researchers in the local context is also a large component of successful adoption.

While glyphosate-resistant horseweed has not previously been reported in California, we suspected that it might exist, especially in noncrop areas. We collected horseweed seeds from two locations in the San Joaquin Valley and treated greenhouse-grown plants at different stages with different amounts of glyphosate. This study showed that a glyphosate-resistant biotype of horseweed exists in the noncrop areas of Dinuba, in Tulare County, and that the level of resistance may be influenced by the plant's growth stage at the time of glyphosate application.

In recent decades, air quality has improved near most cities but not in rural areas such as the San Joaquin Valley. Many studies using diverse exposure techniques have shown that ground-level ozone air pollution reduces plant growth and yield, from negligible impacts in some species to over 30% losses in others. We studied the interaction of ozone with weed competition from yellow nutsedge in Pima cotton and tomato in open-top field-exposure chambers at the UC Kearney Research and Extension Center in Fresno County. Ozone impacts on cotton (which is relatively sensitive) were compounded by weed competition, whereas tomato (which is less sensitive) competed well at all ozone concentrations. Our data suggests that crop-loss estimates obtained in single-factor experiments accurately reflect the serious risk of ozone to agriculture, but that more accurate yield predictions will require the consideration of interactions between the components of complex crop production systems, including weed competition.

Organic farmers and limited-resource growers in the San Joaquin Valley and other agricultural areas in California—many of whom are ethnic minorities—encounter limited options and environmental constraints when seeking economically viable pest management methods. Over the past 8 years, we have conducted weed research and implementation projects on soil solarization at the UC Kearney Research and Extension Center and on farms in the surrounding San Joaquin Valley. In the Kearney studies, small-scale solarization in parsley reduced weed biomass 94% to 99% over the untreated control. Furthermore, in an on-farm study, solarization provided effective weed control for strawberries at a much lower cost than methyl bromide, with comparable yields. This research has provided guidelines and technical support for growers wishing to implement solarization and related techniques for nonchemical soil disinfestation in a wide variety of specialty crops.

Groundwater nitrate contamination in the Central Valley (CV) aquifer of California is a ubiquitous groundwater problem found in various parts of the valley. Heavy irrigation and application of fertilizer over the last several decades have caused groundwater nitrate contamination in several domestic, public and monitoring wells in the CV above EPA’s Maximum Contamination level of 10 mg/L. Source variables, aquifer susceptibility and geochemical variables could affect the contamination rate and groundwater quality in the aquifer. A comparative study was conducted using Geodetector (GED), Principal Component Analysis (PCA) and Geographically Weighted Regression (GWR) to observe which method is most effective at revealing environmental variables that control groundwater nitrate concentration. The GED method detected precipitation, fertilizer, elevation, manure and clay as statistically significant variables. Watersheds with percent of wells above 5 mg/L of nitrate were higher in San Joaquin and Tulare Basin compared to Sacramento Valley. PCA grouped cropland, fertilizer, manure and precipitation as a first principal component, suggesting similar construct of these variables and existence of data redundancy. The GWR model performed better than the OLS model, with lower corrected Akaike Information Criterion (AIC) values, and captured the spatial heterogeneity of fertilizer, precipitation and elevation for the percent of wells above 5 mg/L in the CV. Overall, the GED method was more effective than the PCA and GWR methods in determining the influence of explanatory variables on groundwater nitrate contamination.