217 research outputs found

    MODELING NITRATE CONCENTRATION IN GROUND WATER USING REGRESSION AND NEURAL NETWORKS

    Get PDF
    Nitrate concentration in ground water is a major problem in specific agricultural areas. Using regression and neural networks, this study models nitrate concentration in ground water as a function of iron concentration in ground water, season and distance of the well from a poultry house. Results from both techniques are comparable and show that the distance of the well from a poultry house has a significant effect on nitrate concentration in groundwater.Environmental Economics and Policy, Livestock Production/Industries,

    Quantum Channels and Representation Theory

    Full text link
    In the study of d-dimensional quantum channels (d≥2)(d \geq 2), an assumption which is not very restrictive, and which has a natural physical interpretation, is that the corresponding Kraus operators form a representation of a Lie algebra. Physically, this is a symmetry algebra for the interaction Hamiltonian. This paper begins a systematic study of channels defined by representations; the famous Werner-Holevo channel is one element of this infinite class. We show that the channel derived from the defining representation of SU(n) is a depolarizing channel for all nn, but for most other representations this is not the case. Since the Bloch sphere is not appropriate here, we develop technology which is a generalization of Bloch's technique. Our method works by representing the density matrix as a polynomial in symmetrized products of Lie algebra generators, with coefficients that are symmetric tensors. Using these tensor methods we prove eleven theorems, derive many explicit formulas and show other interesting properties of quantum channels in various dimensions, with various Lie symmetry algebras. We also derive numerical estimates on the size of a generalized ``Bloch sphere'' for certain channels. There remain many open questions which are indicated at various points through the paper.Comment: 28 pages, 1 figur

    MODELING NITROGEN LOADING RATE TO DELAWARE LAKES USING REGRESSION AND NEURAL NETWORKS

    Get PDF
    The objective of this research was to predict the nitrogen-loading rate to Delaware lakes and streams using regression analysis and neural networks. Both models relate nitrogen-loading rate to cropland, soil type and presence of broiler production. Dummy variables were used to represent soil type and the presence of broiler production at a watershed. Data collected by Ritter & Harris (1984) was used in this research. To build the regression model Statistical Analysis System (SAS) was used. NeuroShell Easy Predictor, neural network software was used to develop the neural network model. Model adequacy was established by statistical techniques. A comparison of the regression and neural network models showed that both perform equally well. Cropland was the only significant variable that had any influence on the nitrogen-loading rate according to both the models.Environmental Economics and Policy,

    Yield Reduction from Controlle Flooding of Corn

    Get PDF
    This ISU study was designed to provide more accuracy in estimating flood damages for those concerned with watershed development. But it also reveals just what foes on when a corn field suffers from excess water

    Biodegradation of Aged Residues of Atrazine and Alachlor in a Mix-Load Site Soil by Fungal Enzymes

    Get PDF
    Soils from bulk pesticide mixing and loading (mix-load) sites are often contaminated with a complex mixture of pesticides, herbicides, and other organic compounds used in pesticide formulations that limits the success of remediation efforts. Therefore, there is a need to find remediation strategies that can successfully clean up these mix-load site soils. This paper examined the degradation of atrazine (2-chloro-4-ethylamino-6-isopropylamino-S-triazine; AT) and alachlor (2-chloro-2, 6-diethyl-N-[methoxymethyl]-acetanilide) in contaminated mix-load site soil utilizing an extracellular fungal enzyme solution derived from the white rot fungus, Phanerochaete chrysosporium, grown in a packed bed bioreactor. Thirty-two percent of AT and 54% of AL were transformed in the biometers. The pseudo first-order rate constant for AT and AL biodegradation was 0.0882 d−1 and 0.2504 d−1, respectively. The half-life (1/2) for AT and AL was 8.0 and 3.0 days, respectively. Compared to AT, the initial disappearance of AL proceeded at a faster rate and resulted in a greater amount of AL transformed. Based on the net Co2 evolved from the biometers, about 4% of the AT and AL initially present in the soil was completely mineralized

    Correlation between Laser Fluorescence Readings and Volume of Tooth Preparation in Incipient Occlusal Caries In Vitro

    Full text link
    This study evaluated the correlation between laser fluorescence readings and the extent of incipient occlusal caries as measured by the volume of tooth preparation in vitro.One hundred and three permanent molars and premolars containing incipient occlusal pit-and-fissure caries and sound occlusal surfaces (1/4 of the sample, control) were selected. DIAGNOdent (KaVo Dental Corporation, Lake Zurich, IL, USA) readings were obtained according to manufacturer instructions. Caries was removed with 1/4 round burs in high speed. The volume of tooth preparation was measured using a surrogate measure based on the amount of composite needed to fill the preparations. Sensitivity and specificity using different cutoff values were calculated for lesions/preparations extending into dentin. The results were analyzed statistically.The Pearson correlation for preparation volume and DIAGNOdent reading measurements was low ( r  = 0.285). Sensitivity and specificity of DIAGNOdent for detection of dentinal lesions were 0.83 and 0.60, and 0.66 and 0.73 for the cutoff values of 20 and 30, respectively.Within the limitations of this study, laser fluorescence measured with DIAGNOdent does not correlate well with extent of carious tooth structure in incipient occlusal caries.Clinicians should not rely only on DIAGNOdent readings to determine the extension of incipient occlusal caries.( J Esthet Restor Dent 22:31–41, 2010)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78687/1/j.1708-8240.2009.00309.x.pd

    Metastatic disease to the breast: the Washington University experience

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Metastases to the breast occur rarely, but may be increasing in incidence as patients live longer with malignant diseases. The aim of this study is to characterize metastatic disease to the breast and to describe the management and prognosis of patients who present with this diagnosis.</p> <p>Methods</p> <p>A retrospective review of our institution's pathology and breast cancer databases was performed in order to identify patients with breast malignancies that were not of primary breast origin. Chart review provided additional information about the patients' primary malignancies and course of illness.</p> <p>Results</p> <p>Between 1991 and 2006, eighteen patients with metastatic disease to the breast of non-hematologic origin were identified and all had charts available for review. Among the 18 patients with disease metastatic to the breast, tissues of origin included 3 ovarian, 6 melanoma, 3 medullary thyroid, 3 pulmonary neuroendocrine, 1 pulmonary small cell, 1 oral squamous cell, and 1 renal cell. Overall mean survival after diagnosis of metastatic disease to the breast was 22.4 months. Treatment of metastases varied and included combinations of observation, surgery, radiation, and chemotherapy. Five patients (27.8%) required a change in management of their breast disease for local control.</p> <p>Conclusion</p> <p>Due to the variable course of patients with metastatic disease, a multi-disciplinary approach is necessary for each patient with disease metastatic to the breast to determine optimal treatment. Based on our review, many patients survive for long periods of time and local treatment of metastases to the breast may be beneficial in these patients to prevent local complications.</p

    Il4ra-independent vaginal eosinophil accumulation following helminth infection exacerbates epithelial ulcerative pathology of HSV-2 infection

    Get PDF
    How helminths influence the pathogenesis of sexually transmitted viral infections is not comprehensively understood. Here, we show that an acute helminth infection (Nippostrongylus brasiliensis [Nb]) induced a type 2 immune profile in the female genital tract (FGT). This leads to heightened epithelial ulceration and pathology in subsequent herpes simplex virus (HSV)-2 infection. This was IL-5-dependent but IL-4 receptor alpha (Il4ra) independent, associated with increased FGT eosinophils, raised vaginal IL-33, and enhanced epithelial necrosis. Vaginal eosinophil accumulation was promoted by IL-33 induction following targeted vaginal epithelium damage from a papain challenge. Inhibition of IL-33 protected against Nb-exacerbated HSV-2 pathology. Eosinophil depletion reduced IL-33 release and HSV-2 ulceration in Nb-infected mice. These findings demonstrate that Nb-initiated FGT eosinophil recruitment promotes an eosinophil, IL-33, and IL-5 inflammatory circuit that enhances vaginal epithelial necrosis and pathology following HSV-2 infection. These findings identify a mechanistic framework as to how helminth infections can exacerbate viral-induced vaginal pathology

    Implementation and evaluation of a harm-reduction model for clinical care of substance using pregnant women

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Methamphetamine (MA) use during pregnancy is associated with many pregnancy complications, including preterm birth, small for gestational age, preeclampsia, and abruption. Hawaii has lead the nation in MA use for many years, yet prior to 2007, did not have a comprehensive plan to care for pregnant substance-using women. In 2006, the Hawaii State Legislature funded a pilot perinatal addiction clinic. The Perinatal Addiction Treatment Clinic of Hawaii was built on a harm-reduction model, encompassing perinatal care, transportation, child-care, social services, family planning, motivational incentives, and addiction medicine. We present the implementation model and results from our first one hundred three infants (103) seen over 3 years of operation of the program.</p> <p>Methods</p> <p>Referrals came from community health centers, hospitals, addiction treatment facilities, private physician offices, homeless outreach services and self-referral through word-of-mouth and bus ads. Data to describe sample characteristics and outcome was obtained prospectively and retrospectively from chart abstraction and delivery data. Drug use data was obtained from the women's self-report and random urine toxicology during the pregnancy, as well as urine toxicology at the time of birth on mothers, and urine and meconium toxicology on the infants. Post-partum depression was measured in mothers with the Edinburgh Post-Partum depression scale. Data from Path clinic patients were compared with a representative cohort of women delivering at Kapiolani Medical Center for Women and Children during the same time frame, who were enrolled in another study of pregnancy outcomes. Ethical approval for this study was obtained through the University of Hawaii Committee for Human Studies.</p> <p>Results</p> <p>Between April 2007 and August 2010, 213 women with a past or present history of addiction were seen, 132 were pregnant and 97 delivered during that time. 103 live-born infants were delivered. There were 3 first-trimester Spontaneous Abortions, two 28-week intrauterine fetal deaths, and two sets of twins and 4 repeat pregnancies. Over 50% of the women had lost custody of previous children due to substance use. The majority of women who delivered used methamphetamine (86%), either in the year before pregnancy or during pregnancy. Other drugs include marijuana (59.8%), cocaine (33%), opiates (9.6%), and alcohol (15.2%). Of the women served, 85% smoked cigarettes upon enrollment. Of the 97 women delivered during this period, all but 4 (96%) had negative urine toxicology at the time of delivery. Of the 103 infants, 13 (12.6%) were born preterm, equal to the state and national average, despite having many risk factors for prematurity, including poverty, poor diet, smoking and polysubstance use. Overwhelmingly, the women are parenting their children, > 90% retained custody at 8 weeks. Long-term follow-up showed that women who maintained custody chose long-acting contraceptive methods; while those who lost custody had a very high (> 50%) repeat pregnancy rate at 9 months post delivery.</p> <p>Conclusion</p> <p>Methamphetamine use during pregnancy doesn't exist is isolation. It is often combined with a multitude of other adverse circumstances, including poverty, interpersonal violence, psychiatric comorbidity, polysubstance use, nutritional deficiencies, inadequate health care and stressful life experiences. A comprehensive harm reduction model of perinatal care, which aims to ameliorate some of these difficulties for substance-using women without mandating abstinence, provides exceptional birth outcomes and can be implemented with limited resources.</p
    • …
    corecore