1,216 research outputs found

    Placing the poor while keeping the rich in their place

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    A central objective of modern US housing policy is deconcentrating poverty through "housing mobility programs" that move poor families into middle class neighborhoods. Pursuing these policies too aggressively risks inducing middle class flight, but being too cautious squanders the opportunity to help more poor families. This paper presents a stylized dynamicoptimization model that captures this tension. With base-caseparameter values, cost considerations limit mobility programs before flight becomes excessive. However, for modest departures reflecting stronger flight tendencies and/or weaker destination neighborhoods, other outcomes emerge. In particular, we find state-dependence and multiple equilibria, including both de-populated and oversized outcomes. For certain sets of parameters there exists a Skiba point that separates initial conditions for which the optimal strategy leads to substantial flight and depopulation from those for which the optimal strategy retains or even expands the middle class population. These results suggest the value of estimating middle-class neighborhoods' "carrying capacity" for absorbing mobility program placements and further modeling of dynamic response.housing policy, multiple equilibria, negative externality, optimal control, segregation, separation, Skiba point

    Water relations traits of C4 grasses depend on phylogenetic lineage, photosynthetic pathway, and habitat water availability

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    The repeated evolution of C4 photosynthesis in independent lineages has resulted in distinct biogeographical distributions in different phylogenetic lineages and the variants of C4 photosynthesis. However, most previous studies have only considered C3/C4 differences without considering phylogeny, C4 subtype, or habitat characteristics. We hypothesized that independent lineages of C4 grasses have structural and physiological traits that adapt them to environments with differing water availability. We measured 40 traits of 33 species from two major C4 grass lineages in a common glasshouse environment. Chloridoideae species were shorter, with narrower and longer leaves, smaller but denser stomata, and faster curling leaves than Panicoideae species, but overall differences in leaf hydraulic and gas exchange traits between the two lineages were weak. Chloridoideae species had two different ways to reach higher drought resistance potential than Panicoideae; NAD-ME species used water saving, whereas PCK species used osmotic adjustment. These patterns could be explained by the interactions of lineage×C4 subtype and lineage×habitat water availability in affected traits. Specifically, phylogeny tended to have a stronger influence on structural traits, and C4 subtype had more important effects on physiological traits. Although hydraulic traits did not differ consistently between lineages, they showed strong covariation and relationships with leaf structure. Thus, phylogenetic lineage, photosynthetic pathway, and adaptation to habitat water availability act together to influence the leaf water relations traits of C4 grasses. This work expands our understanding of ecophysiology in major C4 grass lineages, with implications for explaining their regional and global distributions in relation to climate

    Comparison of multispectral remote-sensing techniques for monitoring subsurface drain conditions

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    The following multispectral remote-sensing techniques were compared to determine the most suitable method for routinely monitoring agricultural subsurface drain conditions: airborne scanning, covering the visible through thermal-infrared (IR) portions of the spectrum; color-IR photography; and natural-color photography. Color-IR photography was determined to be the best approach, from the standpoint of both cost and information content. Aerial monitoring of drain conditions for early warning of tile malfunction appears practical. With careful selection of season and rain-induced soil-moisture conditions, extensive regional surveys are possible. Certain locations, such as the Imperial Valley, Calif., are precluded from regional monitoring because of year-round crop rotations and soil stratification conditions. Here, farms with similar crops could time local coverage for bare-field and saturated-soil conditions

    Thinking in action: Need for cognition predicts self-control together with action orientation

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    Need for Cognition describes relatively stable interindividual differences in cognitive motivation. Previous research has shown relations of Need for Cognition to Self-Control–a capacity that can be broadly defined as resistance to temptation–yet, the processes underlying this relation remain unclear. One explanation for the prediction of Self-Control by Need for Cognition can be an increased motivation to invest cognitive effort with higher levels of Need for Cognition. Another possible link could be that individual differences in the implementation of Self-Control intentions may play a moderating or mediating role for the predictive value of Need for Cognition. Such individual differences in the self-motivated initiation and maintenance of intentions are described by dispositional Action Orientation. Therefore, in the present study, Action Orientation was examined with regard to its possible role in explaining the relation of Need for Cognition to Self-Control. In a sample of 1209 young adults, Self-Control was assessed with two different self-report instruments and moderation and mediation models of the relationship between Need for Cognition, Action Orientation, and Self-Control were tested. While there was no evidence for a moderating role of Action Orientation in explaining the relation of Need for Cognition and Self-Control, Action Orientation was found to partly mediate this relation with a remaining direct effect of Need for Cognition on Self-Control. These results add to the conceptual understanding of Need for Cognition and demonstrate the relevance of trait variables to predict Self-Control

    Use of the nutritional risk score by surgeons and nutritionists.

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    BACKGROUND: The Nutritional Risk Score (NRS) is a validated tool to identify patients who should benefit of nutritional interventions. Nutritional screening however has not yet been widely adopted by surgeons. Furthermore, the question about reliability of nutritional assessment performed by surgeons is still unanswered. METHODS: Data was obtained from a recent randomised trial including 146 patients with an NRS ≥3 as assessed by the surgeons. Additional detailed nutritional assessment was performed for all patients by nutritional specialists and entered prospectively in a dedicated database. In this retrospective, surgeons' scoring of NRS and its components was compared to the assessment by nutritionists (considered as gold standard). RESULTS: Prospective NRS scores by surgeons and nutritionists were available for 141 patients (97%). Surgeons calculated a NRS of 7, 6, 5, 4 and 3 in 2, 8, 38, 21 and 72 patients respectively. Nutritionists calculated a NRS of 6, 5, 4, 3 and 2 in 8, 26, 47, 57, 3 patients, respectively. Surgeons' assessment was entirely correct in 56 patients (40%), while at least the final score was consistent in 63 patients (45%). Surgeons overrated the NRS in 21% of patients and underestimated the score in 29%. Evaluation of the nutritional status showed most of the discrepancies (54%). CONCLUSION: Surgeon's assessment of nutritional status is modest at best. Close collaboration with nutritional specialists should be recommended in order to avoid misdiagnosis and under-treatment of patients at nutritional risk

    Pressurized IntraPeritoneal Aerosol Chemotherapy - Practical aspects.

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    Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) has been introduced as novel treatment for peritoneal carcinomatosis. Only proper patient selection, stringent safety protocol and careful surgery allow for a secure procedure. We hereby report the essentials for safe implementation. All consecutive procedures within 20 months after PIPAC implementation were analyzed with regards to practical and surgical aspects. Special emphasis was laid on modifications of technique and safety measures during the implementation process with systematic use of a dedicated checklist. Further, surgical difficulty was documented by use of a visual analogue scale (VAS). 127 PIPAC procedures were performed in 58 patients from January 2015 until October 2016. 81% of patients had at least one previous laparotomy. Median operation time was 91 min (87-103) for the first 20 cases, 93 min (IQR 88-107) for PIPAC21-50, and 103 min (IQR 91-121) for the following 77 procedures. Primary and secondary non-access occurred in 3 patients (2%), all of them having prior hyperthermic intraperitoneal chemotherapy (HIPEC). Using open Hasson technique, one single bowel lesion occurred, which was the only intraoperative complication. One 5 mm and another 10/12 mm trocar were used in 88% of procedures while additional trocars were needed in 12%. No leak of cytostatics was observed and no procedure needed to be stopped. VAS for overall difficulty of the procedure was 3 ± 2.4, and 3 ± 2.9 and 3 ± 2.5, respectively, for abdominal access and intraoperative staging. With standardized surgical approach and dedicated safety checklist, PIPAC can be safely introduced in clinical routine with minimal learning curve

    Enantioselective Gas Chromatographic Analysis of Cyclopropane Derivatives

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    Chirasil-β-Dex was used as chiral stationary phase for the enantioselective gas chromatographic analysis of several new chiral cyclopropane derivatives. The GC method provides information about the chemical yields of the cyclopropane products, enantioselectivity, substrate specifity, and catalytic activity of the chiral catalysts used in the inter- and intra-molecular cyclopropanation reactions and avoids time-consuming work-up procedure

    Impact of an Operating Room Nurse Preoperative Dialogue on Anxiety, Satisfaction and Early Postoperative Outcomes in Patients Undergoing Major Visceral Surgery-A Single Center, Open-Label, Randomized Controlled Trial.

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    Anxiety is common before surgery and known to negatively impact recovery from surgery. The aim of this study was to evaluate the impact of a preoperative nurse dialogue on a patient's anxiety, satisfaction and early postoperative outcomes. This 1:1 randomized controlled trial compared patients undergoing major visceral surgery after a semistructured preoperative nurse dialogue (interventional group: IG) to a control group (CG) without nursing intervention prior to surgery. Anxiety was measured with the autoevaluation scale State-Trait Anxiety Inventory (STAI, Y-form) pre and postoperatively. The European Organization for Research and Treatment of Cancer (EORTC) In-Patsat32 questionnaire was used to assess patient satisfaction at discharge. Further outcomes included postoperative pain (visual analogue scale: VAS 0-10), postoperative nausea and vomiting (PONV), opiate consumption and length of stay (LOS). Over a period of 6 months, 35 participants were randomized to either group with no drop-out or loss to follow-up (total n = 70). The median score of preoperative anxiety was 40 (IQR 33-55) in the IG vs. 61 (IQR 52-68) in the CG (p < 0.001). Postoperative anxiety levels were comparable 34 (IQR 25-46) vs. 32 (IQR 25-44) for IG and CG, respectively (p = 0.579). The IG did not present higher overall satisfaction (90 ± 15 vs. 82.9 ± 16, p = 0.057), and pain at Day 2 was similar (1.3 ± 1.7 vs. 2 ± 1.9, p = 0.077), while opiate consumption, PONV levels and LOS were comparable. A preoperative dialogue with a patient-centered approach helped to reduce preoperative anxiety in patients undergoing major visceral surgery

    Postoperative urinary retention in colorectal surgery within an enhanced recovery pathway.

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    Enhanced recovery after surgery (ERAS) guidelines for colorectal surgery suggest routine transurethral bladder drainage with early removal to prevent urinary tract infection (UTI). The aim of this study was to identify risk factors for urinary retention (UR). This retrospective analysis included all colorectal patients since ERAS implementation in May 2011-November 2014. From the prospective ERAS database, over 100 items related to demographics, surgery, compliance, and outcome were analyzed. Risk factors for UR were identified by multiple logistic regressions; then, UR was correlated to functional outcomes and UTI and acute kidney injury rates. The study cohort consisted of 513 consecutive patients. Of these, 73 patients (14%) presented with UR. Multivariate analysis identified male gender (odds ratio 1.4; 95% CI, 1-1.8; P = 0.045) and postoperative thoracic epidural analgesia (EDA; odds ratio 2.6; 95% CI, 1.6-4.3; P ≤ 0.001) as independent risk factors for postoperative UR. Functional recovery was impeded in patients with UR, who were less mobile (mobilization day 1 >4 h: 57% versus 70%, P = 0.024) and gained more weight (2.8 ± 2.5 kg versus 1.6 ±3 kg on day 1, P = 0.001) due to fluid overload. Furthermore, patients with urinary catheters reported more pain (visual analog scales day 3: 3.1 ± 2.5 versus 2.2 ± 2.4, P = 0.002) and depended longer on intravenous fluid administration (termination of intravenous fluids later than day 1: 53% versus 39%, P = 0.021). Ten of 73 patients (14%) developed UTI in patients with UR and 42 of 440 (10%) in patients without UR (P = 0.276). Six of 73 patients (8%) developed acute kidney injury in patients with UR and 36 of 440 (8%) in patients without UR (P = 0.991). Male gender and EDA were independent risk factors for postoperative UR which appeared to be a significant impediment for functional recovery
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