Band Placements Research Articles

Insights into effect of dopant site and dopant concentration on structural, electronic and optical properties of GaNbO[formula omitted] and its implications on visible light photocatalytic behavior: An ab-initio study

First principles electronic structure calculations were performed on pure and chalcogenide doped GaNbO4. Doping with isoelectronic S and Se at the O sites in GaNbO4 shows a dopant site driven anisotropy in the structural properties which affects its electronic, optical and photocatalytic behavior. Band gap reduction in GaNbO4 is more with Se than S and this reduction can be regulated via choice of dopant, dopant site and dopant concentration. GaNbO4 bears an optical absorption profile similarity with anatase TiO2 (a-TiO2). Besides directional anisotropy, dopant induced absorption in the visible regime displays a site driven anisotropy, which, has implications on the onset of absorption and absorption peak heights. The visible region absorption peaks can be modulated with changes in the dopant concentration. Se dopant at a lower concentration gives a broader visible regime absorption peak of similar peak height as of a higher concentration S dopant. Undoped GaNbO4 has valence band maxima and conduction band minima at similar energies as a-TiO2 and these band placements can be altered through choice of dopant element, dopant site and dopant concentration to tune the visible light photocatalytic performance. Our study shows that doped GaNbO4 has a stronger visible range absorption than doped a-TiO2.

Long-acting mechanisms of concentrated urea application — High urea concentrations are biological inhibitors

The concentrated application of urea (CAU; including band and hole placements) promotes cereal crop (e.g., rice and summer maize) yields and nitrogen (N) use efficiency by prolonging the retention of N fertilizer in the soil and reducing N loss. However, the long-acting mechanisms of CAU are not well understood. This study investigated the interactions between N transformation and soil microbes in the special micro-region around the fertilization point with the CAU, using a simulation experiment with two types of soil (silty loam and sandy loam). The soil samples were subjected to six N treatments: 1000, 3000, 5000, 10,000, 30,000 mg N kg−1, and dicyandiamide with 1000 mg N kg−1; no urea treatment was a control. Soil bacterial community compositions (examined using MiSeq sequencing), the abundance of ammonia-oxidizing microbes (quantified using real-time PCR), including ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA), and the soil chemical properties were assessed at 20 and 60 days after urea application. The high soil ammonium concentration caused by CAU affected the soil bacterial community by changing the soil chemical properties. Soil ammonium concentration and pH were the main factors affecting microbial communities and amoA gene abundance of AOA and AOB. The 10,000 and 30,000 mg N kg−1 dosages for the silty loam soil and 30,000 mg N kg−1 dosage for the sandy loam soil in this simulation experiment significantly (p < 0.05) reduced bacterial α-diversity, amoA gene abundance of AOA and AOB, and inhibited nitrification throughout the culture period. However, the inhibitory effects of high soil N application concentration on nitrification weakened as the culture time increased. Overall, CAU acted as a biological nitrification inhibitor by maintaining high soil ammonium concentration, which decreases activity of AOA and AOB amoaA genes for a long time (>60 days).

Bioring® gastric banding for obesity in a private South African hospital

Background: Obesity is a significant health problem in South Africa. Surgery is the most effective means of durable weight loss for the morbidly obese. Of the surgical options, laparoscopic adjustable gastric banding is the most controversial. We aimed to assess a single surgeon’s experience with a specific band. Methods: A retrospective observational study of a continuous cohort of laparoscopic adjustable gastric Cousin Bioring® band placements from a single private South African hospital was conducted. Three hundred and fifty bands were placed in 347 patients, 75% were female. Variables analysed were BMI obesity class, comorbidities, weight loss, diabetes resolution, adherence to aftercare, patient satisfaction, complications and death. Results: Outcomes were assessed in 343 patients (4 patients lost to follow-up). The mean follow-up was 39 months (IQR 29–66 months). The mean preoperative BMI was 43.3 kg/m2 (IQR 37.4–47.6 kg/m2). Most weight loss occurred in the first year, and 66% achieved > 40% excess weight loss. Resolution of type 2 diabetes and prediabetes occurred in 56.4% and 89.8% of patients respectively. Increasing age (p = 0.002), class 3 obesity (p < 0.001) and suboptimal aftercare (p < 0.001) were associated with failure. One patient developed band erosion and 40 developed band slippage, 34 of whom underwent secondary surgery (32 removals, 2 revisions). All complications were grade I–III. There was no high grade complication, and no death. Conclusions: Bioring® gastric banding achieved moderately good weight loss and resolution of type 2 diabetes with a low complication rate. BMI > 60 and suboptimal aftercare predicted poor outcome.

Banding of Fertilizer Improves Phosphorus Acquisition and Yield of Zero Tillage Maize by Concentrating Phosphorus in Surface Soil

Zero tillage increases stratification of immobile nutrients such as P. However, it is unclear whether near-surface stratification of soil P eases or hampers P uptake by maize (Zea mays L.) which needs an optimum P supply at/before six–leaf–stage to achieve potential grain yield. The aim of the three-year study was to determine whether P stratification, under zero tillage, impaired yield of maize and which P placement methods could improve P uptake on an Aeric Albaquept soil subgroup. Phosphorus fertilizer was placed by: (a) broadcasting before final tillage and sowing of seeds; (b) surface banding beside the row; and (c) deep banding beside the row (both the band placements were done at three–four leaf stage) Phosphorus treatments were repeated for 3 years along with three tillage practices viz.: (a) zero tillage (ZT); (b) conventional tillage (12 cm; CT); and (c) deep tillage (25 cm; DT). In the third year, all the tillage practices gave similar yield of Bangladesh Agricultural Research Institute (BARI) hybrid maize–5, but the highest grain yield was obtained by surface band P placement. After three years of tillage and P placements, the root mass density (RMD) at 0–6 cm depth increased significantly from 1.40 mg cm−3 in DT under deep band placement to 1.98 mg cm−3 in ZT under surface band placement, but not at the other depths. The combination of ZT practices, with broadcast or surface band placement methods, produced the highest available, and total P, content in soil at 0–6 cm depth after harvesting of maize. Accordingly, a significant increase in P uptake by maize was also found with surface banding of P alone and also in combination with ZT. Organic carbon, and total N, also increased significantly at depths of 0–6 cm after three years in ZT treatments with P placed in bands. By contrast, CT and DT practices, under all placement methods, resulted in an even distribution of P up to 24 cm depth. Phosphorus application, by surface banding at the three–four leaf stage, led to increased P uptake at early growth and silking stages, which resulted in highest yield regardless of tillage type through increased extractable P in the soil. Even though ZT increased P stratification near the soil surface, and it increased plant available water content (PAWC) and RMD in the 0–6 cm depth, as did surface banding, it did not improve maize grain yield. Further research is needed to understanding the contrasting maize grain yield responses to P stratification.

Radiographic predictability of hiatal hernia prior to gastric band surgery.

Background:Hiatal hernia (HH) is closely associated with morbid obesity. There is controversy over the need for preoperative imaging before laparoscopic adjustable gastric band placement. The aim of this study is to determine the predictive value of preoperatively diagnosing HH with upper gastrointestinal (UGI) series imaging.Methods:A retrospective review of a single surgeon's experience with laparoscopic adjustable gastric band placements was performed. All patients received a preoperative UGI series. The decision to perform an HH repair at the time of gastric banding was based on intraoperative findings. Each patient's UGI study was compared with the operative report. Patients' outpatient records were also reviewed for subjective reflux symptoms or use of antireflux medications.Results:Of 146 patients, 63 (43%) had intraoperative findings consistent with an HH and underwent repair. Of these, only 32 (50%) had a preoperative UGI study that showed an HH (positive predictive value, 50%). Of the 83 patients who did not have an intraoperative HH, only 51 (61%) had a congruent UGI (negative predictive value, 62%). No correlation was found between patient-reported symptoms and either radiologic or intraoperative findings.Conclusions:UGI series have poor positive and negative predictive values in preoperatively diagnosing HH. In addition, subjective patient symptoms and the need for antireflux medication did not correlate with either radiologic or intraoperative findings of HH. Our results suggest that direct operative diagnosis is a more accurate method of detecting HH.

Progressive hip rehabilitation: The effects of resistance band placement on gluteal activation during two common exercises

BackgroundA critical issue for constructing a progressive rehabilitation program is the knowledge of muscle activation levels across exercises and within exercise modifications. Many exercises are offered to enhance gluteal muscle activation during functional rehabilitation but little data exists to guide the progression of exercise intensity during rehabilitation. The objective of this paper was to examine the effects of altering resistance band placement during ‘Monster Walks’ and ‘Sumo Walks.’ MethodsNine healthy male volunteers formed a convenience sample. Sixteen electromyography channels measured neural drive of selected muscles of the right hip and torso muscles. Three resistance band placements (around the knees, ankles and feet) during the two exercises were utilized to provide a progressive resistance to the gluteal muscles while repeated measures ANOVA with Bonferroni adjustment was used to assess differences in mean EMG. The presentation of exercises and band placement were randomized. FindingsExamining muscle activation profiles in the three hip muscles of interest revealed the progressive nature of the neural drive when altering band placement. Tensor fascia latae (TFL) demonstrated a progressive activation moving the band from the knee to the distal band placement, but not between the ankle and foot placements. Gluteus medius demonstrated a progressive activation moving distally between band placements. Gluteus maximus was preferentially activated only during the foot placement. InterpretationThe band placements offered a progressive increase in resistance for hip rehabilitation, specifically the gluteal muscles. The added benefit of placing the band around the forefoot was selective enhancement of the gluteal muscles versus TFL presumably by adding an external rotation effort to the hips. This information may assist those who address gluteal activation patterns for patients suffering hip and back conditions where gluteal activation has been affected.

Preliminary Surgical Results of Single-Incision Transumbilical Laparoscopic Bariatric Surgery

BackgroundRecently, single-incision laparoscopic surgery (SILS) has been used for bariatric procedures, and this surgery is considered a type of minimally invasive surgery. When SILS is performed via the transumbilical route, the resultant abdominal wound is hidden and the cosmetic outcome is better. However, because of the small angle of manipulation and difficulty in liver traction, this technique is not used to perform complex bariatric surgery. In this prospective study, we used our novel technique, which involves the use of a liver-suspension tape and umbilicoplasty of an omega-shaped incision (omega umbilicoplasty), to perform laparoscopic bariatric surgery via the single-incision transumbilical (SITU) approach. We then assessed the safety and effectiveness of our surgical technique.MethodsWe started performing and developing this technique from December 2008. Until July 2009, 40 consecutive patients underwent 40 bariatric procedures: two adjustable gastric band placements, six sleeve gastrectomies, and 32 Roux-en-Y gastric bypass operations, including five cases where concomitant cholecystectomy was performed.ResultsThe mean operation time was 93.4 min and the mean duration of postoperative hospitalization was 1.15 days. No perioperative or postoperative complications or deaths occurred. Most patients were very satisfied with the cosmetic outcomes.ConclusionOur technique can be safely and effectively used for SITU laparoscopic bariatric surgery. This technique will soon be used for advanced abdominal surgeries besides bariatric ones.

Influence of Urea Fertilizer Placement on Nitrous Oxide Production from a Silt Loam Soil

Urea placement in band or nests has been shown to enhance N use efficiency, but limited work has been done to assess its affect on N(2)O emissions. This study compared N(2)O emissions from urea prills applied to an Amsterdam silt loam (fine-silty, mixed, superactive, frigid Typic Haplustolls) using broadcast, band, and nest placements. Experiments were conducted in greenhouse pots (200 kg N ha(-1)) and in canola (Brassica rapa L.) seeded fields using rates of 100 kg N ha(-1) (recommended) and 200 kg N ha(-1). Urea placement affected N(2)O emission patterns and cumulative N(2)O losses in the greenhouse and field. Urea prills placed in nests, and sometimes bands delayed N(2)O production with peak flux activity occurring later, and elevated emission activity being more prolonged than for broadcast applications. Differences were more obvious at 200 kg N ha(-1). These effects were attributed to a delay in urea hydrolysis and inhibition of nitrification. The fraction of applied urea-N lost as N(2)O for broadcast, band, and nest placements applied at the recommended rate averaged 2.0, 2.7, and 5.8 g N kg(-1) N, respectively. The fraction of applied urea-N lost as N(2)O averaged 2.9, 10.4, and 9.2 g N kg(-1) N for broadcast, band, and nest placements when urea-N rate was increased from 100 to 200 kg N ha(-1), respectively. Greater N(2)O production with nest placement may in part be due to significant soil NO(2)-N accumulations. Potential benefits to crop fertilizer use efficiency that come with placement of urea in concentrated zones may lead to enhanced N(2)O production.

Primary midline peritoneal access with optical trocar is safe and effective in morbidly obese patients

Background The bladed optical access trocar is widely used and provides convenient, safe peritoneal entry. However, it has only been approved for use after insufflation. We used this device as our primary method of entry before insufflation in bariatric surgery and provide an overview of our cumulative experience. In addition, we provide a comprehensive analysis of the published data with respect to optical access as both primary and secondary methods of peritoneal access. Methods From July 30, 2001 to April 4, 2008, laparoscopic access for all bariatric surgery at a single center was achieved using the 5–12-mm optical bladed trocar without previous insufflation for 2207 cases, including 1692 laparoscopic gastric bypass procedures and 515 laparoscopic adjustable gastric band placements. Results Four vascular injuries occurred (.18%) in our series. Three required conversion to laparotomy and vascular repair, and one was managed laparoscopically. All injuries occurred with off-midline placement. No mortalities occurred secondary to the use of the optical trocar. Conclusion The present report is as the greatest volume series detailing the safe and effective use of the bladed optical trocar without previous insufflation as the primary method of peritoneal access in the morbidly obese. The insertion of this device in the midline appears to be a safe method of entry.

Management of failed adjustable gastric banding

About 100,000 adjustable gastric band placements have been performed worldwide, but more than 10% of patients have needed reoperation for insufficient weight loss or device-related complications. This study investigates the complications following gastric banding, and the outcome using a structured management strategy. In the period April 1996 to January 2002, 824 severely obese patients (body mass index 43 +/- 1 kg/m 2 [mean +/- standard error under the mean], age 43 +/- 1 years; 77% women) underwent gastric banding in a single institution and were followed prospectively. Complications, insufficient weight loss, and subsequent management were analyzed. By the fifth treatment year, excess weight loss (EWL) was 54.8 +/- 1.7%; 72.8% of patients lost weight continuously or attained EWL of at least 50%. Insufficient weight loss occurred in 143 patients, and band-related complications occurred in 131 patients, with a mean annual rate of 5.0%. Major reoperation was necessary in 121 patients, and the annual reoperation rate was 4.7%. Following major reoperation, band- and bypass-related complication rates ranged from 6.3% to 11.7% per year. Three deaths occurred, 1 after reoperation and 2 due to preexisting cardiovascular disease. Applying a structured reoperation algorithm, 5% annual failure after banding was corrected in most patients, and 72.8% of patients attained sufficient weight loss. Reoperation-related mortality was low (.8%), and its annual morbidity was acceptable (4.6%).

Laboratory studies on performance of positive feed metering devices for band placement of fertilizers

The effect of shape, number of grooves and speed of fluted roller metering device was studied on metering characteristics of urea for intermittent and continuous band placements. For intermittent band placement, 6 groove rollers of U-shape, J-shape and eccentric-circular shape were used whereas 12 groove rollers of U-shape and eccentric circular shape were selected for continuous band placement. The principle of two stage metering of fertilizer was employed using a star type agitator running ~t a constant speed of 0.26 m/s and a fixed circular opening of 13.5 mm diameter in the hopper at the first stage and varying speeds of 28,42, 52, 68 and 85 rpm for positive feed fluted rollers at the second stage. The results showed higher percentage deposition of urea in 100 mm bands with J-shape fluted roller followed by eccentric circular and U-shape fluted rollers. In case of continuous band placement, the coefficient of variation ranged from 20.11 to 11.17% with eccentric circular shape and 15.79 to 9.45% with U-shape fluted roller with increase in speed from 28 to 85 rpm.

Grain Yield, Early Growth, and Nutrient Uptake of No‐Till Soybean as Affected by Phosphorus and Potassium Placement

More information is needed about P and K placement for no‐till soybean [Glycine max (L.) Merr.]. This study evaluated plant responses to P and K fertilization and placement in 10 long‐term trials and 11 short‐term trials in Iowa from 1994 to 1997. Treatments were various P and K rates broadcast, banded with the planter, and deep banded (at a 15‐ to 20‐cm depth). Measurements were plant weight, P uptake, and K uptake at the V5 stage and grain yield. Phosphorus fertilization increased yield when soil‐test P (STP) was less than 9 mg P kg−1 (Bray‐P1) at a 0‐ to 15‐cm depth or 12 mg P kg−1 at a 0‐ to 7.5‐cm depth. The P placement did not influence yield. The band K placements produced slightly higher yield than the broadcast placement. Responses to K were not related to soil‐test K (STK) levels, which varied from 90 to 262 mg K kg−1 (ammonium acetate), or stratification. The P or K placement had little influence on early growth but influenced early P and K uptake. Banding with the planter was more effective than broadcasting for P uptake, and the two band placements were more effective for K uptake. Only the responses of K uptake and grain yield to banded K were correlated across sites. A shallow sampling depth will improve only slightly the prediction of response to P. The observed small no‐till soybean yield response to banded K would seldom offset increased application costs in similar soils.

Effects of rates and placement methods of urea and potassium chloride on soil nitrogen and potassium and corn dry matter yield

Placement and interaction of urea and KCl fertilizers for corn production needs to be evaluated to develop rational fertilizer management programs. A field study, involving three rates of urea and KCl with band and broadcast placements, was conducted with corn on two Quebec soils in 1988 and 1989 to determine nutrient interactions on corn (Zea mays L.) dry matter yields, N and P uptake and on soil N and K. In two sites (Chicot 1988 and Ormstown 1989) with dry surface soils, no rainfall for 5 d and significant rainfall after 5 d, broadcast urea resulted in higher dry matter yields and uptake of N than banded urea. In the Chicot 1989 site where urea application was on moist soil and followed by rainfall insufficient to move broadcast urea into the soil, banded urea was more effective than broadcast urea. Banded urea generally resulted in increased inorganic N and fixed [Formula: see text] in soil sampled from within fertilizer bands but lower levels in soil between bands in comparison with broadcast urea. Banding KCl resulted in increased exchangeable K+ in the band. Compared with exchangeable K+, fixed K+ was less affected by placement methods and rates of added N and K. Interactions between rates and placement methods of N and K on dry matter yield, N and K uptake and soil N and K were few and relatively small. Key words: Fertilizer placement, urea, KCl, Zea mays, grain, corn

Current management practices for correcting iron deficiency in plants with emphasis on soil management

Abstract Many different kinds of soil additives have been studied with the aim of preventing and/or correcting iron deficiencies of plants. Application rates have varied from as little as “parts per million”; of several Fe chelates, to as much as many tons per hectare of acidifying soil amendments, or organic materials such as manures, sewage sludges and plant residues. The chelate Fe EDDHA has generally been considered to be the most effective soil applied material in alleviating chlorosis: its use is somewhat limited, however, by its relatively high cost. Broadcast applications of acidifying materials such as elemental sulfur and sulfuric acid must generally be excessively high to be effective. Recent studies involving band placements of these acidifying materials have shown some promise. Several industrial by‐products have also proven effective, especially when concentrated in bands close to germinating seeds.

Nitrogen, Salinity, and Acidity Distribution in an Irrigated Orchard Soil as Affected by Placement of Nitrogen Fertilizers

AbstractA field experiment was conducted to determine the vertical and lateral changes in the distribution of nitrogen, salinity, and acidity occurring in an irrigated orchard soil following addition of (NH4)2SO4, NH4NO3, or Ca(NO3)2 by broadcast, in broad band, or in narrow band. The NH4 and NO3 contents in soil decreased rapidly even under narrow band placements. Considerable nitrate movement was observed. After 1 year, neither the total nor the inorganic N level in the fertilized plots was significantly different from that of the control. High salinity was detected under the narrow band placements, but the level diminished rapidly with time. Little salinity was evident under the broad band or broadcast placements. However, the acidity produced by the ammonium fertilizers persisted after 1 year. Changes in soil properties under narrow bands were drastic, whereas changes under broad bands were insignificant.

ABSORPTION OF FERTILIZER PHOSPHORUS BY SUGAR BEETS AS INFLUENCED BY PLACEMENT OF PHOSPHORUS AND NITROGEN

A greenhouse study was conducted to determine the effects of placement of phosphorus and nitrogen on absorption of fertilizer phosphorus by sugar beets. Seven placements of P-32-labelled concentrated superphosphate combined with three nitrogen treatments—ON, 20 lb. N mixed with the soil, and 20 lb. N applied with the phosphorus—were used. The nitrogen source was ammonium nitrate. The phosphorus placements included three band placements, two applications mixed with 2 inches of soil at the 3–5 inch depth with and without a starter, and two applications mixed with 2 inches of soil at the 0–2 inch depth with and without a starter.The placement of nitrogen had a greater influence on the uptake of fertilizer phosphorus than did the placement of phosphorus. Nitrogen applied with the phosphorus generally resulted in greater uptake of fertilizer phosphorus than did nitrogen mixed with the soil. The nitrogen was more effective when the phosphorus was banded than when it was mixed with a volume of soil 2 inches deep. When no nitrogen was added or when nitrogen was mixed with the soil, a shallow band placement or the applications mixed with 2 inches of soil were equally effective in supplying phosphorus to the plant, and were superior to either a deep band or a mixed application with a starter. However, when nitrogen was added with the phosphorus, the shallow and deep bands were equally effective and were superior to the mixed applications with or without a starter.

Availability of Phosphorus in Granulated Fertilizers

AbstractA greenhouse test to measure the effect of placement, granule size, and the relative phosphate fixing capacity of the soil upon the efficiency of superphosphate and dicalcium phosphate was performed. The materials, labeled with P32, granulated, and sized to 4–6, 8–10, 14–20, 28–35, and −35 mesh were used in band and mixed placements on Evesboro and Davidson soils. A major difficulty encountered in greenhouse experimentation with granulated fertilizers stems from the problem of securing small samples for pot application that truly represent the test materials. Even with close‐sized materials the minimum representative sample of coarse granules is several‐fold larger than the quantity required for pot application. The test crop was wheat. Using increased yields, total phosphorus uptake, and percentage of the plant phosphorus derived from the fertilizer as criteria of agronomic value, the 14–20 mesh granules of superphosphate were the best size tested with this material while the 28–35 and −35 were the best sizes tested with dicalcium phosphate.