Decomposition, nitrogen and carbon mineralization from food and cover crop residues in the central plateau of Haiti.

Cover crops are a major focus of conservation agriculture efforts because they can provide soil cover and increase nutrient availability after their mineralization in cropping systems. To evaluate the effect of residue type and placement on rate of decomposition and carbon (C) and nitrogen (N) mineralization, residues from two food crops, maize (Zea mays L.) and common bean (Phaseolus vulgaris L.), and two promising cover crops, sunn hemp (Crotalaria juncea L.) and sorghum sudangrass (Sorghum bicolor [L.] Moench x S. bicolor var. Sudanese [Piper] Stapf) were used in a litterbag study in the Central Plateau region of Haiti from May to September, 2013. Residues were placed in litterbags at a rate equivalent to 3.25 Mg residue ha(-1) either on the soil surface or buried at 15 cm to represent a tilled and no-tillage system, respectively. Initial C:N ratios were: maize > common bean > sorghum sudangrass > sunn hemp. Highest residue mass loss rates and C and N mineralization generally occurred in the reverse order. Overall, surface-placed residues decomposed more slowly with 40 and 17 % of initial residue mass of surface and buried residues, respectively, remaining at 112 days. Carbon and N mineralization was higher when residues were buried. Net N mineralization of buried residues was 0.12, 0.07, 0.06, and 0.03 g N g residue(-1) for sunn hemp, sorghum sudangrass, maize, and common bean, respectively over 112 days. To achieve the goal of increasing nutrient supply while maintaining year-round cover, a combination of grass and legume cover crops may be required with benefits increasing over multiple seasons.

Diffuse, encasing lymphangioma of the supraglottis.

BACKGROUND: Lymphangioma of the head and neck is considered a rare congenital tumor with the vast majority presenting before two years of age. Surgical excision and sclerosing therapy using OK-432 are recognized as effective treatment options for the majority of these lesions; however, treatment options of laryngeal lesions are less straightforward due to the risk of airway compromise and the desire to maintain the integrity of a functional larynx. We present the case of a four month old male who presented with chief complaint of inspiratory stridor after a single episode of pneumonia. His clinical presentation, flexible fiberoptic laryngoscopic examination, and operative evaluation were consistent with a lymphangioma completely encasing the epiglottis and arytenoids and isolated to the supraglottis. This report outlines our approach to workup and treatment of this rare lesion. METHOD: Case report of presentation, diagnosis and treatment is presented. RESULTS: A four-month old male presented to ENT clinic with inspiratory stridor, worsened with crying, without frank respiratory distress. History and initial examination was consistent with airway obstruction. Flexible fiberoptic laryngoscopy showed laryngomalacia as well as diffuse and symmetric supraglottic edema. Surgical evaluation identified edema limited to the supraglottis, notably along the ventral surface of the epiglottis and dorsal surface of bilateral arytenoids. Biopsies were taken and immunohistochemical staining was performed with strong positivity for D2-40 and CD31, supporting the diagnosis of isolated lymphangioma of the supraglottis. Treatment was performed through multiple point spot welding with a fiber equipped CO2 LASER (OmniGuide TM) at 5 watt continuous power. CONCLUSION: Isolated supraglottic lymphangioma was diagnosed via direct laryngoscopy, with pathologic and immunohistochemical confirmation. Carbon dioxide laser spot welding technique was used with excellent clinical improvement in stridor. Clinical improvement is sustained after 6 months follow-up.

Light-induced charge separation in anatase TiO2 particles.

Ultraviolet light-induced electron-hole pair excitations in anatase TiO(2) powders were studied by a combination of electron paramagnetic resonance and infrared spectroscopy measurements. During continuous UV irradiation in the mW.cm(-2) range, photogenerated electrons are either trapped at localized sites, giving paramagnetic Ti(3+) centers, or remain in the conduction band as EPR silent species which may be observed by their IR absorption. Using low temperatures (90 K) to reduce the rate of the electron-hole recombination processes, trapped electrons and conduction band electrons exhibit lifetimes of hours. The EPR-detected holes produced by photoexcitation are O(-) species, produced from lattice O(2-) ions. It is found that under high vacuum conditions, the major fraction of photoexcited electrons remains in the conduction band. At 298 K, all stable hole and electron states are lost from TiO(2). Defect sites produced by oxygen removal during annealing of anatase TiO(2) are found to produce a Ti(3+) EPR spectrum identical to that of trapped electrons, which originate from photoexcitation of oxidized TiO(2). Efficient electron scavenging by adsorbed O(2) at 140 K is found to produce two long-lived O(2)(-) surface species associated with different cation surface sites. Reduced TiO(2), produced by annealing in vacuum, has been shown to be less efficient in hole trapping than oxidized TiO(2).

Quantifying stratospheric ozone in the upper troposphere with in situ measurements of HCl.

We have developed a chemical ionization mass spectrometry technique for precise in situ measurements of hydrochloric acid (HCl) from a high-altitude aircraft. In measurements at subtropical latitudes, minimum HCl values found in the upper troposphere (UT) were often near or below the detection limit of the measurements (0.005 parts per billion by volume), indicating that background HCl values are much lower than a global mean estimate. However, significant abundances of HCl were observed in many UT air parcels, as a result of stratosphere-to-troposphere transport events. We developed a method for diagnosing the amount of stratospheric ozone in these UT parcels using the compact linear correlation of HCl with ozone found throughout the lower stratosphere (LS). Expanded use of this method will lead to improved quantification of cross-tropopause transport events and validation of global chemical transport models.

Evidence that nitric acid increases relative humidity in low-temperature cirrus clouds.

In situ measurements of the relative humidity with respect to ice (RHi) and of nitric acid (HNO3) were made in both natural and contrail cirrus clouds in the upper troposphere. At temperatures lower than 202 kelvin, RHi values show a sharp increase to average values of over 130% in both cloud types. These enhanced RHi values are attributed to the presence of a new class of HNO3-containing ice particles (Delta-ice). We propose that surface HNO3 molecules prevent the ice/vapor system from reaching equilibrium by a mechanism similar to that of freezing point depression by antifreeze proteins. Delta-ice represents a new link between global climate and natural and anthropogenic nitrogen oxide emissions. Including Delta-ice in climate models will alter simulated cirrus properties and the distribution of upper tropospheric water vapor.

Carbon isotope discrimination and bundle sheath leakiness in three C(4) subtypes grown under variable nitrogen, water and atmospheric CO(2) supply.

The changes in composition and productivity of semi-arid C(4) grassland, anticipated with rising atmospheric CO(2), will depend on soil water and nutrient availability. The interactive effects of soil resource limitation and elevated CO(2 )on these grasses, furthermore, may vary among C(4) biochemical subtypes (NADP-ME, NAD-ME, PCK) that differ in bundle sheath leakiness (Phi) responses to drought and nitrogen supply. To address C(4) subtype responses to soil resource gradients, the carbon isotope discrimination (Delta), bundle sheath leakiness (Phi), leaf gas exchange (A, g(s), c(i)/c(a)) and above-ground biomass accumulation were measured on three dominant grasses of semi-desert grassland in south-eastern Arizona. Bouteloua curtipendula (PCK), Aristida glabrata (NADP-ME) and the non-native Eragrostis lehmanniana (NAD-ME) were grown in controlled-environment chambers from seed under a complete, multi-factorial combination of present ambient (370 ppm) and elevated (690 ppm) CO(2) concentration and under high and low water and nitrogen supply. E. lehmanniana (NAD-ME) had the highest photosynthetic rate (A) and lowest Phi compared to the other two grasses when grown under low nitrogen and water availability. However, favourable water and nitrogen supply and elevated atmospheric CO(2) enhanced photosynthetic performance and above-ground biomass production of B. curtipendula (PCK) to a greater extent than in A. glabrata and E. lehmanniana. Contrary to pre vious studies, Phi and Delta in the NADP-ME subtype (A. glabrata) were most affected by changing environmental conditions compared to the other subtypes; deviations from the classic NADP-ME anatomy in Aristida could have accounted for this result. Overall, response of semi-arid grasslands to rising atmospheric CO(2) may depend more on species-specific responses to drought and nitrogen limitation than on general C(4) subtype responses.

Metabolic and anthropometric factors related to skeletal muscle UCP3 gene expression in healthy human adults.

This cross-sectional investigation sought to determine the relationship between selected metabolic, endocrine, and anthropometric factors and skeletal muscle UCP3 mRNA in healthy adult humans. Twenty-four healthy adults (13 male and 11 female) across a range of aerobic capacity, age, and body composition were studied. Muscle biopsies were obtained from the vastus lateralis, from which UCP3 mRNA was quantified by Northern blot, and fiber type was determined by use of the myosin ATPase staining procedure. In addition, resting energy expenditure and maximum rate of oxygen consumption were determined by indirect calorimetry, body composition was determined by dual-energy X-ray absorptiometry, and fasting plasma leptin and insulin were determined by ELISA. UCP3 mRNA was correlated positively with the percent type I fibers (r = 0.842, P < 0.001), plasma leptin (r = 0.454, P = 0.026), and plasma insulin (r = 0.615, P < 0.001) and inversely to age (r = -0.411, P = 0.046). Stepwise multiple regression analysis determined that percent type I muscle fibers was the best predictor of vastus lateralis UCP3 mRNA, and no other variable entered the equation (model r(2) = 0.66). This study suggests that of the variables measured, UCP3 mRNA is primarily related to skeletal muscle fiber type in healthy adults. The factors that contribute to fiber-specific differences in UCP3 mRNA expression will need to be examined in future studies.

Modulation of dopamine uptake in rat nucleus accumbens: effect of specific dopamine receptor antagonists and sigma ligands.

The ability of dopamine (DA) antagonists and sigma receptor ligands to alter [(3)H]-DA uptake was examined using synaptosomes prepared from the nucleus accumbens of female rats. Pre-incubation with compounds having a high affinity for sigma (rimcazole, haloperidol, and spiperone) receptors produced dose dependent inhibition of (3)H-DA uptake. Sulpiride, a pure DA D(2) antagonist had no effect. In contrast, DA uptake was potentiated in response to (+)-3-(3-hydroxyphenyl)-N-(1-propyl)piperidine, a mixed sigma receptor antagonist and DA D(2) receptor agonist. Similarly, SKF-10,047, a selective sigma receptor agonist, and progesterone, a putative endogenous ligand for the sigma receptor, produced significant increases in (3)[H]-DA uptake. These data suggest a potential role for sigma and DA ligands in the regulation of DA uptake in the nucleus accumbens.

Alteration of dopamine transport in the striatum and nucleus accumbens of ovariectomized and estrogen-primed rats following N-(p-isothiocyanatophenethyl) spiperone (NIPS) treatment.

The ability of N-(p-isothiocyanatophenethyl) spiperone (NIPS, 10 mg/kg, 24 h), a selective, irreversible alkylating agent of the dopamine D(2) receptor, to alter properties of dopamine uptake and clearance in the striatum and nucleus accumbens of ovariectomized and estrogen-primed (estradiol benzoate, 10 microg, 48 h, 24 h) rats was examined using voltammetry. The effectiveness of NIPS was evaluated independently by measuring agonist mediated potentiation of [35S]-guanosine 5'-(gamma-thiotriphosphate) ([35S]-GTPgammaS) binding and [3H]-dopamine uptake. A decrease in E(max) for ligand potentiated [35S]-GTPgammaS binding and a loss of quinpirole potentiated [3H]-dopamine uptake was observed consistent with a NIPS mediated alkylation and functional down-regulation of the dopamine D(2) receptor. This down-regulation was associated with an attenuation of the dose dependent uptake of dopamine in both the striatum and the accumbens. Co-administration of estrogen and NIPS resulted in a further attenuation of dopamine potentiated [35S]-GTPgammaS binding measured in vitro and dopamine uptake measured in vivo. Analysis of the voltammetric profile revealed that clearance and T(50) times were significantly prolonged in animals treated with estrogen and NIPS compared with those treated with NIPS alone. These data are consistent with both a steroid mediated impairment in dopamine autoreceptor/dopamine transporter coupling and an independent action of estrogen at the level of the dopamine transporter.

The detection of large HNO3-containing particles in the winter Arctic stratosphere.

Large particles containing nitric acid (HNO3) were observed in the 1999/2000 Arctic winter stratosphere. These in situ observations were made over a large altitude range (16 to 21 kilometers) and horizontal extent (1800 kilometers) on several airborne sampling flights during a period of several weeks. With diameters of 10 to 20 micrometers, these sedimenting particles have significant potential to denitrify the lower stratosphere. A microphysical model of nitric acid trihydrate particles is able to simulate the growth and sedimentation of these large sizes in the lower stratosphere, but the nucleation process is not yet known. Accurate modeling of the formation of these large particles is essential for understanding Arctic denitrification and predicting future Arctic ozone abundances.

Estrogen priming modulates autoreceptor-mediated potentiation of dopamine uptake.

The ability of a physiological dose of estrogen (estradiol benzoate, estrogen: 10 microgram 48 and 24 h prior) to modulate autoreceptor-mediated changes in dopamine transport properties was investigated in a synaptosomal preparation prepared from the nucleus accumbens of ovariectomized rats. Quinpirole (1-100 microM)-mediated potentiation of [3H]dopamine uptake was attenuated in synaptosomes from estrogen-primed animals. Haloperidol (10 microM) inhibited basal uptake and effectively prevented quinpirole potentiation of uptake in both ovariectomized and estrogen-primed samples. The ability of selective protein phosphatase inhibitors to modulate autoreceptor-mediated potentiation of dopamine uptake was also examined. Pretreatment with protein phosphatase 2B (deltamethrin, cypermethrin) or protein phosphatase 1 (tautomycin) inhibitors attenuated basal and quinpirole-potentiated dopamine uptake in ovariectomized but not estrogen-primed tissue. These data suggest that autoreceptor-mediated activation of dopamine transport can be regulated by physiological doses of estrogen and implicate a role for protein phosphorylation in autoreceptor-mediated potentiation of dopamine uptake.

Women's health problems in soap operas: a content analysis.

A content analysis of women's health problems in network daytime serials is reported. Results indicate a preponderance of such problems as substance abuse, falls resulting in death or injury, comas or unconsciousness, mental health concerns (most notably represented by amnesia and multiple personality), concerns about AIDS, automobile accidents, being drugged, fainting, pregnancy problems, and violent acts resulting in harm. Such concerns as breast and cervical cancer and heart disease are less frequently portrayed.

Attenuation of dopamine uptake in vivo following priming with estradiol benzoate.

Dopamine (DA) uptake and clearance were examined using in vivo voltammetry following injection of DA (200 microM) into the nucleus accumbens of ovariectomized (OVX) or OVX-estrogen-primed rats (estradiol benzoate, EB, 10 microg 48 and 24 h prior to experiment). The rate of DA uptake was significantly attenuated in steroid-treated animals: this decrease was accompanied by a significant increase in DA clearance time. Quinpirole (0.5 mg/kg) modulated the kinetics of DA uptake in OVX but not EB-primed rats. These data suggest that DA clearance can be regulated by physiological doses of EB.

Prevalence of broad-host-range lytic bacteriophages of Sphaerotilus natans, Escherichia coli, and Pseudomonas aeruginosa.

Two bacteriophage collections were examined with regard to their ability to form plaques on multiple bacterial host species. Nine of 10 phages studied were found to be broad-host-range bacteriophages. These phages fell into two groups. Group 1, the SN series, was isolated from sewage treatment plant samples with Sphaerotilus natans ATCC 13338 as a host. The DNAs of these bacteriophages contained modified bases and were insensitive to cleavage by type I and II restriction endonucleases. The efficiency of plating of these bacteriophages was changed only slightly on the alternate host. Group 2, the BHR series, was isolated by a two-host enrichment protocol. These bacteriophages were sensitive to restriction, and their efficiency of plating was dramatically reduced on the alternate host. Our results suggest that a multiple-host enrichment protocol may be more effective for the isolation of broad-host-range bacteriophages by avoiding the selection bias inherent in single-host methods. At least two of the broad-host-range bacteriophages mediated generalized transduction. We suggest that broad-host-range bacteriophages play a key role in phage ecology and gene transfer in nature.

Modulation of mesolimbic dopaminergic activity over the rat estrous cycle.

Clinical observations have suggested that ovarian steroid hormones modulate the symptomology of psychiatric disorders and this modulation is thought to be due to a protective effect of estrogen on dopaminergic activity. To test this hypothesis, mesolimbic dopamine (DA) activity was examined in relationship to endogenous hormone levels. Using in vivo electrochemical techniques, K+-stimulated DA release was measured in the nucleus accumbens of control, intact cycling female rats and experimental rats which had received bilateral 6-hydroxydopamine (6-OHDA) lesions to the medial prefrontal cortex (PFC) to produce subcortical hyperactivity. DA release and reuptake fluctuated with changes in circulating steroid levels in both control and lesion groups. In non-lesioned control rats, stimulated DA release peaked during diestrus I (DI) and was attenuated during diestrus II (DII) and estrus. DA transport, as measured by a change in T1/2 time, was significantly potentiated during proestrus. The expression of subcortical hyperactivity following lesions to the medial PFC appeared to be dependent on the steroid environment; during DII an increased responsiveness was observed while a significant decrease in K+-stimulated release was observed during DI. These cyclic changes in DA release were not associated with dramatic changes in DA transport except during proestrus when transport was significantly prolonged. These data suggest that cyclic fluctuation of ovarian steroids may modulate DA activity presynaptically through an alteration in both release and reuptake and that this modulation effectively dampens the expression of subcortical hyperactivity except under specific hormonal conditions.

Patients' perspectives on the management of emotional distress in primary care settings.

OBJECTIVE: To investigate how important treatment for emotional distress is to primary care patients in general and to primary care patients with depression, and to evaluate the types of mental health interventions they desire. DESIGN: Patient surveys. SETTING: Five private primary care practices. MEASUREMENTS AND MAIN RESULTS: Patients' desire for treatment of emotional distress and for specific types of mental health interventions were measured, as well as patients' ratings of the impact of emotional distress, the frequency of depressive symptoms, and mental health functioning. Of the 403 patients, 33% felt that it was "somewhat important" and 30% thought it was "extremely important" that their physician tries to help them with their emotional distress. Patient desire for this help was significantly related to a diagnosis of depression (p < .001), perceptions about the impact of emotional distress (p < .001), and mental health functioning (p < .001). Among patients with presumptive diagnoses of major and minor depression, 84% and 79%, respectively, felt that it was at least somewhat important that they receive this help from their physician. Sixty-one percent of all primary care patients surveyed and 69% of depressed patients desired counseling: 23% of all patients and 33% of depressed patients wanted a medication: and 11% of all patients and 5% of depressed patients desired a referral to a mental health specialist. CONCLUSIONS: A majority of these primary care patients and almost all of the depressed patients felt that it was at least somewhat important to receive help from their physician for emotional distress. The desire for this help seems to be related to the severity of the mental health problem. Most of the patients wanted counseling, but relatively few desired a referral to a mental health specialist.

Using successful models of care to guide the teaching of psychiatry in primary care.

The focus of efforts to improve primary care physicians' recognition and treatment of psychiatric conditions has been on enhancing the content of their education, with little attention paid to the choice of models through which the content is delivered. The authors believe that existing models of primary care delivery are analogous to Strain's six basic models of teaching psychiatry to primary care physicians. Each model is especially suited to a particular segment of the primary care physician's education; for example, the consultation model has relevance for teaching about better management of identified patients and the bridge model for enhancing recognition of unrecognized disorders. All six models have a place in both education and practice.

Challenges and opportunities for consultation-liaison psychiatry in the managed care environment.

While the evolving managed care revolution is dramatically changing the clinical, educational, and economic systems in which consultation-liaison (C-L) psychiatrists must operate, this revolution also present several important opportunities for those in C-L psychiatry. The authors, who are academic department chairs and formerly directed C-L divisions, discuss C-L psychiatry's potential involvement and suggest approaches to effectively address key aspects of these changes.