Wheat leaves emit nitrous oxide during nitrate assimilation

Nitrous oxide (N2O) is a key atmospheric greenhouse gas that contributes to global climatic change through radiative warming and depletion of stratospheric ozone. In this report, N2O flux was monitored simultaneously with photosynthetic CO2 and O2 exchanges from intact canopies of 12 wheat seedlings. The rates of N2O-N emitted ranged from <2 pmol⋅m−2⋅s−1 when NH\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} \begin{equation*}{\mathrm{_{4}^{+}}}\end{equation*}\end{document} was the N source, to 25.6 ± 1.7 pmol⋅m−2⋅s−1 (mean ± SE, n = 13) when the N source was shifted to NO\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} \begin{equation*}{\mathrm{_{3}^{-}}}\end{equation*}\end{document}. Such fluxes are among the smallest reported for any trace gas emitted by a higher plant. Leaf N2O emissions were correlated with leaf nitrate assimilation activity, as measured by using the assimilation quotient, the ratio of CO2 assimilated to O2 evolved. 15N isotopic signatures on N2O emitted from leaves supported direct N2O production by plant NO\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} \begin{equation*}{\mathrm{_{3}^{-}}}\end{equation*}\end{document} assimilation and not N2O produced by microorganisms on root surfaces and emitted in the transpiration stream. In vitro production of N2O by both intact chloroplasts and nitrite reductase, but not by nitrate reductase, indicated that N2O produced by leaves occurred during photoassimilation of NO\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} \begin{equation*}{\mathrm{_{2}^{-}}}\end{equation*}\end{document} in the chloroplast. Given the large quantities of NO\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} \begin{equation*}{\mathrm{_{3}^{-}}}\end{equation*}\end{document} assimilated by plants in the terrestrial biosphere, these observations suggest that formation of N2O during NO\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} \begin{equation*}{\mathrm{_{2}^{-}}}\end{equation*}\end{document} photoassimilation could be an important global biogenic N2O source.

The cranium of Parapithecus grangeri, an Egyptian Oligocene anthropoidean primate

A nearly complete skull of Parapithecus grangeri from the early Oligocene of Egypt is described. The specimen is relatively undistorted and is undoubtedly the most complete higher primate skull yet found in the African Oligocene, which also makes it the most complete Oligocene primate cranium worldwide. Belonging in superfamily Parapithecoidea, a group regarded by some as the sister group to all other Anthropoidea, this skull reveals important information about the radiation of stem anthropoideans. This cranium is about 15% larger than size estimates based on a fragmentary cranium of its contemporary and close relative Apidium phiomense. It is about the same size as that of the gray gentle lemur, Hapalemur griseus, or of platyrrhines such as the owl monkey, Aotus trivirgatus, or the titi monkey, Callicebus torquatus. Comparatively small orbits and size differences in jaws and teeth show it was both diurnal and dimorphic. This is the only specimen of the species that shows (from sockets) that there were four small upper incisors. Several mandibular specimens of the species establish that there were no permanent lower incisors and that the symphysis was fused. Like other early anthropoideans this species possessed a lower encephalization quotient and less-developed orbital frontality than later anthropoideans. There is full postorbital closure and fusion of the metopic suture, and the ectotympanic forms a rim to the auditory aperture. A probable frontal/alisphenoid contact is a potentially derived resemblance to Catarrhini. A proposed separate genus for the species P. grangeri is not sustained.

How are close residues of protein structures distributed in primary sequence?

Structurally neighboring residues are categorized according to their separation in the primary sequence as proximal (1-4 positions apart) and otherwise distal, which in turn is divided into near (5-20 positions), far (21-50 positions), very far ( > 50 positions), and interchain (from different chains of the same structure). These categories describe the linear distance histogram (LDH) for three-dimensional neighboring residue types. Among the main results are the following: (i) nearest-neighbor hydrophobic residues tend to be increasingly distally separated in the linear sequence, thus most often connecting distinct secondary structure units. (ii) The LDHs of oppositely charged nearest-neighbors emphasize proximal positions with a subsidiary maximum for very far positions. (iii) Cysteine-cysteine structural interactions rarely involve proximal positions. (iv) The greatest numbers of interchain specific nearest-neighbors in protein structures are composed of oppositely charged residues. (v) The largest fraction of side-chain neighboring residues from beta-strands involves near positions, emphasizing associations between consecutive strands. (vi) Exposed residue pairs are predominantly located in proximal linear positions, while buried residue pairs principally correspond to far or very far distal positions. The results are principally invariant to protein sizes, amino acid usages, linear distance normalizations, and over- and underrepresentations among nearest-neighbor types. Interpretations and hypotheses concerning the LDHs, particularly those of hydrophobic and charged pairings, are discussed with respect to protein stability and functionality. The pronounced occurrence of oppositely charged interchain contacts is consistent with many observations on protein complexes where multichain stabilization is facilitated by electrostatic interactions.

Very-long-baseline radio interferometry surveys of the compact structure in active galactic nuclei.

Very-long-baseline radio interferometry (VLBI) imaging surveys have been undertaken since the late 1970s. The sample sizes were initially limited to a few tens of objects but the snapshot technique has now allowed samples containing almost 200 sources to be studied. The overwhelming majority of powerful compact sources are asymmetric corejects of one form or another, most of which exhibit apparent superluminal motion. However 5-10% of powerful flat-spectrum sources are 100-parsec (pc)-scale compact symmetric objects; these appear to form a continuum with the 1-kpc-scale double-lobed compact steep-spectrum sources, which make up 15-20% of lower frequency samples. It is likely that these sub-galactic-size symmetric sources are the precursors to the large-scale classical double sources. There is a surprising peak around 90 degrees in the histogram of misalignments between the dominant source axes on parsec and kiloparsec scales; this seems to be associated with sources exhibiting a high degree of relativistic beaming. VLBI snapshot surveys have great cosmological potential via measurements of both proper motion and angular size vs. redshift as well as searches for gravitational "millilensing."

Cognición no social y neuroimagen en TEA sin discapacidad intelectual

La presente tesis doctoral está constituida por tres estudios independientes pero relacionados entre sí: 1) Estimation of the intelligence quotient using Wechsler intelligence scales in children and adolescents with Asperger syndrome (SA), 2) Executive function is affected in autism spectrum disorder, but does not correlate with intelligence, y 3) Reduced gyrification is related to reduced interhemispheric connectivity in autism spectrum disorders. El objetivo general es estudiar las alteraciones cognitivas en niños y adolescentes con un Trastorno del Espectro Autista (TEA) sin discapacidad intelectual (SDI) asociada, particularmente en cuanto a sus aspectos en funcionamiento general (puntuaciones en escala de inteligencia Wechsler) y funciones ejecutivas, y estudiar la girificación y conectividad en el córtex prefrontal teniendo en cuenta su relación con las funciones ejecutivas. Como objetivos específicos: i) Medir los perfiles de inteligencia en niños y adolescentes con SA; ii) Evaluar la validez de cinco formas abreviadas de las escalas Wechsler de inteligencia en niños y adolescentes con SA, frente a la versión completa, teniendo en cuenta los criterios propuestos por Resnick & Entin, (1971); iii) Evaluar las funciones ejecutivas en una muestra homogénea de niños y adolescentes con TEA-SDI y comparar sus puntuaciones con las obtenidas por un grupo de niños y adolescentes sanos pareados por edad, años de educación, sexo, estatus socioeconómico y cociente intelectual (CI); iv) Evaluar si los déficits en funciones ejecutivas correlacionan con déficits en inteligencia general; v) Evaluar si los déficits en funcionamiento ejecutivo en los niños y adolescentes con TEA-SDI correlacionan con su nivel de funcionamiento o con la gravedad de los síntomas que presentan; vi) Estudiar la relación entre girificación y conectividad de la sustancia blanca, prestando especial atención a los cambios relacionados con la edad en una muestra de pacientes con TEA de alto funcionamiento; vii) Estudiar la girificación y conectividad en el córtex prefrontal teniendo en cuenta su relación con las funciones ejecutivas; y viii) Replicar los resultados obtenidos en nuestra muestra con los datos procedentes de una base independiente de niños y adolescentes con autismo de alto funcionamiento (Autism Brain Imaging Data Exchange, ABIDE)...

Análise da correlação entre índices radiomorfométricos de densidade óssea, perfil de qualidade óssea em software de implante, quociente de estabilidade e torque de inserção em implantes

A qualidade óssea, bem como a estabilidade inicial dos implantes, está diretamente relacionada com o sucesso das reabilitações na implantodontia. O presente estudo teve como objetivo analisar a correlação entre índices radiomorfométricos de densidade óssea por meio de radiografias panorâmicas, perfil de qualidade óssea com o auxílio de Tomografia Computadorizada de Feixe Cônico (TCFC) com o uso do software de imagens OsiriX, Análise da Frequência de Ressonância (RFA) e Torque de Inserção do implante. Foram avaliados 160 implantes de 72 indivíduos, com média etária de 55,5 (±10,5) anos. Nas radiografias panorâmicas foram obtidos os índices IM, IPM e ICM, e nas tomografias computadorizadas de feixe cônico, os valores de pixels e a espessura da cortical da crista óssea alveolar, além da estabilidade primária por meio do torque de inserção e análise da frequência de ressonância. Os resultados foram analisados pelo coeficiente de correlação de Spearman, para p<= 0,01 foi obtido entre o torque de inserção e valores de pixels (0.330), o torque de inserção e a espessura da cortical da crista alveolar (0.339), o torque de inserção e o ISQ vestibulo-lingual (0.193), os valores de pixels e espessura da cortical da crista alveolar (0.377), as duas direções vestíbulo-lingual e mesio-distal do ISQ (0.674), o ISQ vestíbulo-lingual e a espessura da cortical da crista alveolar (0.270); os índices radiomorfométricos foram correlacionados entre eles e para p<= 0,05 foi obtido entre torque de inserção e ISQ mesio-distal (0.131), entre o ISQ vestibulo-lingual e os valores de pixels (0.156) e ISQ mesio-distal e IPMI esquerdo (0.149) e ISQ mesio-distal e IPMS esquerdo (0.145). Existe correlação entre a TCFC, o torque de inserção e a RFA na avaliação da qualidade óssea. É possível utilizar, pré-cirurgicamente, os exames de TCFC para avaliar a qualidade e quantidade óssea, tendo em vista as correlações obtidas neste estudo.

Efeito da aplicação de composto orgânico sobre a qualidade do solo cultivado com cana-de-açúcar (Saccharum spp.)

A dinâmica ambiental possui capacidade limitada de reciclagem e a crescente utilização resíduos agroindustriais, especialmente na agricultura, pode levar a situações de poluição do solo e demais componentes ambientais. A manutenção da produtividade de ecossistemas agrícolas e naturais depende do processo de transformação da matéria orgânica e, por conseguinte, da biomassa microbiana do solo, e que é responsável pela decomposição e mineralização de resíduos no mesmo. A dinâmica natural dos microrganismos do solo, em constante mudança e adaptação, os torna um indicador sensível às mudanças resultantes de diferentes práticas de manejo agrícola. Sendo assim, conhecer essas alterações e suas interferências é fundamental para identificar estratégias adequadas de manejo, apontando técnicas de utilização adequadas. O objetivo deste trabalho foi avaliar a qualidade de um solo agrícola, cultivado com três variedades de cana-de-açúcar (Saccharum spp.), comparando a utilização de adubação mineral frente à utilização de fertilizante orgânico composto no período final de formação dos perfilhos (120 dias após o plantio). Foi implantado, em condições de campo, o cultivo de cana-de-açúcar (cana planta), utilizando as variedades RB 867515, RB 962869 e RB 855453, onde cada variedade foi cultivada de três formas distintas, sendo elas: plantio controle (CT) sem aplicação de insumos para adubação; plantio orgânico (OG) com aplicação de fertilizante orgânico; e plantio convencional (CV) com aplicação de adubação mineral, seguindo recomendações de adubação após análise química inicial do solo local. Cada parcela possuía 37 m2, com 5 sulcos de 5,0 m de comprimento e espaçamento de 1,5 m entrelinhas, sendo os três sulcos centrais formando a área útil. De acordo com a variedade e o tipo de adubação, foram formados nove tratamentos: T1 86CT, T2 96CT, T3 85CT, T4 6OG, T5 96OG, T6 85OG, T7 86CV, T8 96CV e T9 85CV, com delineamento estatístico de blocos ao acaso e quatro repetições. Os parâmetros químicos do solo analisados foram macronutrientes e micronutrientes; os parâmetros microbiológicos foram carbono da biomassa microbiana (CBM), respiração basal do solo (RBS), quociente metabólico (qCO2), número mais provável de fungos e bactérias do solo (NMP); e, por fim, a produtividade agrícola (t/ha). Os resultados foram submetidos a análise de variância (ANOVA) e à comparação das médias através do teste de Tukey (10%). Também foi realizada a análise de variância dos dados e correlação cofenética de Pearson para formação de dendogramas. Com base no período estudado, considerado como fase crítica da formação do canavial, concluiu-se que os parâmetros químicos que evidenciaram alterações no solo foram pH e os macronutrientes Mg, Al e SB, sendo os tratamentos orgânicos equivalentes e/ou melhores que os tratamentos convencionais. Para os parâmetros microbiológicos, o NMP de fungos apresentou os maiores valores nos tratamentos convencionais e controle. A produtividade agrícola não foi influenciada pelos diferentes tratamentos e insumos utilizados, independente da variedade de cana-de-açúcar utilizada. Por fim, foram observadas correlações positivas entre as variáveis CTC e quociente metabólico (qCO2) apontando potencial melhoria da qualidade do solo, com o emprego de insumos orgânicos

Human Motion Analysis Based on Sequential Modeling of Radar Signal and Stereo Image Features

Falls are one of the greatest threats to elderly health in their daily living routines and activities. Therefore, it is very important to detect falls of an elderly in a timely and accurate manner, so that immediate response and proper care can be provided, by sending fall alarms to caregivers. Radar is an effective non-intrusive sensing modality which is well suited for this purpose, which can detect human motions in all types of environments, penetrate walls and fabrics, preserve privacy, and is insensitive to lighting conditions. Micro-Doppler features are utilized in radar signal corresponding to human body motions and gait to detect falls using a narrowband pulse-Doppler radar. Human motions cause time-varying Doppler signatures, which are analyzed using time-frequency representations and matching pursuit decomposition (MPD) for feature extraction and fall detection. The extracted features include MPD features and the principal components of the time-frequency signal representations. To analyze the sequential characteristics of typical falls, the extracted features are used for training and testing hidden Markov models (HMM) in different falling scenarios. Experimental results demonstrate that the proposed algorithm and method achieve fast and accurate fall detections. The risk of falls increases sharply when the elderly or patients try to exit beds. Thus, if a bed exit can be detected at an early stage of this motion, the related injuries can be prevented with a high probability. To detect bed exit for fall prevention, the trajectory of head movements is used for recognize such human motion. A head detector is trained using the histogram of oriented gradient (HOG) features of the head and shoulder areas from recorded bed exit images. A data association algorithm is applied on the head detection results to eliminate head detection false alarms. Then the three dimensional (3D) head trajectories are constructed by matching scale-invariant feature transform (SIFT) keypoints in the detected head areas from both the left and right stereo images. The extracted 3D head trajectories are used for training and testing an HMM based classifier for recognizing bed exit activities. The results of the classifier are presented and discussed in the thesis, which demonstrates the effectiveness of the proposed stereo vision based bed exit detection approach.

Calibration of the length of a chain of single gold atoms

Using a scanning tunnelling microscope or mechanically controllable break junction it has been shown that it is possible to control the formation of a wire made of single gold atoms. In these experiments an interatomic distance between atoms in the chain of ∼3.6 Å was reported which is not consistent with recent theoretical calculations. Here, using precise calibration procedures for both techniques, we measure the length of the atomic chains. Based on the distance between the peaks observed in the chain length histogram we find the mean value of the interatomic distance before chain rupture to be 2.5±0.2 Å. This value agrees with the theoretical calculations for the bond length. The discrepancy with the previous experimental measurements was due to the presence of He gas, that was used to promote the thermal contact, and which affects the value of the work function that is commonly used to calibrate distances in scanning tunnelling microscopy and mechanically controllable break junctions at low temperatures.

Diversité floristique du peuplement à Pistacia atlantica Desf. dans la région de Béchar (Sud-ouest algérien)

La conservation des groupements à Pistacia atlantica dans la région de Béchar est actuellement menacée par une forte pression humaine et animale. Ce travail consiste à proposer une analyse phyto-écologique fine en se basant sur la dynamique de végétation et les inventaires floristiques. Les explications sont étayées par une analyse statistique (AFC) afin de mieux cerner les facteurs écologiques prépondérants. Nous savons très bien que Pistacia atlantica est une espèce d’avenir pour l’Algérie occidentale, son adaptation au stress écologique lui permet une dynamique et une remontée biologique certaine. Cette espèce peut vivre dans des endroits très secs, de 700 à 1200m d’altitude où la pluviométrie ne dépasse guère les 100 mm/an, avec une température maximale de 42°C et un quotient pluviothermique (Q2) supérieur à 7. La diversité floristique du groupement à Pistacia atlantica est très particulière du fait de sa caractérisation biologique, systématique et phytogéographique. Cet examen fait ressortir l’importance des espèces Saharienne-Endémiques grâce à une adaptation et une résistance plus favorables sous bioclimat typiquement saharien.

Looking twice at the gender equity index for public health impact

Background: It has been shown that gender equity has a positive impact on the everyday activities of people (decision making, income allocation, application and observance of norms/rules) which affect their health. Gender equity is also a crucial determinant of health inequalities at national level; thus, monitoring is important for surveillance of women’s and men’s health as well as for future health policy initiatives. The Gender Equity Index (GEI) was designed to show inequity solely towards women. Given that the value under scrutiny is equity, in this paper a modified version of the GEI is proposed, the MGEI, which highlights the inequities affecting both sexes. Methods: Rather than calculating gender gaps by means of a quotient of proportions, gaps in the MGEI are expressed in absolute terms (differences in proportions). The Spearman’s rank coefficient, calculated from country rankings obtained according to both indexes, was used to evaluate the level of concordance between both classifications. To compare the degree of sensitivity and obtain the inequity by the two methods, the variation coefficient of the GEI and MGEI values was calculated. Results: Country rankings according to GEI and MGEI values showed a high correlation (rank coef. = 0.95). The MGEI presented greater dispersion (43.8%) than the GEI (19.27%). Inequity towards men was identified in the education gap (rank coef. = 0.36) when using the MGEI. According to this method, many countries shared the same absolute value for education but with opposite signs, for example Azerbaijan (−0.022) and Belgium (0.022), reflecting inequity towards women and men, respectively. This also occurred in the empowerment gap with the technical and professional job component (Brunei:-0.120 vs. Australia, Canada Iceland and the U.S.A.: 0.120). Conclusion: The MGEI identifies and highlights the different areas of inequities between gender groups. It thus overcomes the shortcomings of the GEI related to the aim for which this latter was created, namely measuring gender equity, and is therefore of great use to policy makers who wish to understand and monitor the results of specific equity policies and to determine the length of time for which these policies should be maintained in order to correct long-standing structural discrimination against women.

Comparing the distribution of the electronic gap of an organic molecule with its photoluminescence spectrum

The electronic gap structure of the organic molecule N,N′-diphenyl-N,N′-bis(3-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine, also known as TPD, has been studied by means of a Scanning Tunneling Microscope (STM) and by Photoluminescence (PL) analysis. Hundreds of current-voltage characteristics measured at different spots of the sample show the typical behavior of a semiconductor. The analysis of the curves allows to construct a gap distribution histogram which reassembles the PL spectrum of this compound. This analysis demonstrates that STM can give relevant information, not only related to the expected value of a semiconductor gap but also on its distribution which affects its physical properties such as its PL.

MOREMATA: Stata module (Mata) to provide various functions

This package includes various Mata functions. kern(): various kernel functions; kint(): kernel integral functions; kdel0(): canonical bandwidth of kernel; quantile(): quantile function; median(): median; iqrange(): inter-quartile range; ecdf(): cumulative distribution function; relrank(): grade transformation; ranks(): ranks/cumulative frequencies; freq(): compute frequency counts; histogram(): produce histogram data; mgof(): multinomial goodness-of-fit tests; collapse(): summary statistics by subgroups; _collapse(): summary statistics by subgroups; gini(): Gini coefficient; sample(): draw random sample; srswr(): SRS with replacement; srswor(): SRS without replacement; upswr(): UPS with replacement; upswor(): UPS without replacement; bs(): bootstrap estimation; bs2(): bootstrap estimation; bs_report(): report bootstrap results; jk(): jackknife estimation; jk_report(): report jackknife results; subset(): obtain subsets, one at a time; composition(): obtain compositions, one by one; ncompositions(): determine number of compositions; partition(): obtain partitions, one at a time; npartitionss(): determine number of partitions; rsubset(): draw random subset; rcomposition(): draw random composition; colvar(): variance, by column; meancolvar(): mean and variance, by column; variance0(): population variance; meanvariance0(): mean and population variance; mse(): mean squared error; colmse(): mean squared error, by column; sse(): sum of squared errors; colsse(): sum of squared errors, by column; benford(): Benford distribution; cauchy(): cumulative Cauchy-Lorentz dist.; cauchyden(): Cauchy-Lorentz density; cauchytail(): reverse cumulative Cauchy-Lorentz; invcauchy(): inverse cumulative Cauchy-Lorentz; rbinomial(): generate binomial random numbers; cebinomial(): cond. expect. of binomial r.v.; root(): Brent's univariate zero finder; nrroot(): Newton-Raphson zero finder; finvert(): univariate function inverter; integrate_sr(): univariate function integration (Simpson's rule); integrate_38(): univariate function integration (Simpson's 3/8 rule); ipolate(): linear interpolation; polint(): polynomial inter-/extrapolation; plot(): Draw twoway plot; _plot(): Draw twoway plot; panels(): identify nested panel structure; _panels(): identify panel sizes; npanels(): identify number of panels; nunique(): count number of distinct values; nuniqrows(): count number of unique rows; isconstant(): whether matrix is constant; nobs(): number of observations; colrunsum(): running sum of each column; linbin(): linear binning; fastlinbin(): fast linear binning; exactbin(): exact binning; makegrid(): equally spaced grid points; cut(): categorize data vector; posof(): find element in vector; which(): positions of nonzero elements; locate(): search an ordered vector; hunt(): consecutive search; cond(): matrix conditional operator; expand(): duplicate single rows/columns; _expand(): duplicate rows/columns in place; repeat(): duplicate contents as a whole; _repeat(): duplicate contents in place; unorder2(): stable version of unorder(); jumble2(): stable version of jumble(); _jumble2(): stable version of _jumble(); pieces(): break string into pieces; npieces(): count number of pieces; _npieces(): count number of pieces; invtokens(): reverse of tokens(); realofstr(): convert string into real; strexpand(): expand string argument; matlist(): display a (real) matrix; insheet(): read spreadsheet file; infile(): read free-format file; outsheet(): write spreadsheet file; callf(): pass optional args to function; callf_setup(): setup for mm_callf().

Primary productivity and mass fluxes for four stations in teh equatorial Pacific (Table 1)

Primary productivity (14C) and mass flux measurements using a free-drifting sediment trap deployed at 900 m were made at four stations in the Pacific Ocean between 12°N and 6°S at 153°W. The latitudinal variations in productivity were consistent with historical patterns showing the equator as a zone of high production and the oligotrophic waters north of the equatorial region as an area of low productivity. The correlation coefficient between the two sets of independent measurements was 0.999, indicating that in this oceanic area the activity of the primary producers was closely related to the total mass flux. A re-examination of historical data suggests that the downward flux of particulate organic carbon varies in direct proportion to the quotient of surface primary production raised to the 1.4 power and depth raised to the 0.63 power.

A discussion of cases in the 2001 RCPA-AQAP chemical pathology case report comments program

Aim: We present a descriptive analysis of the 10 case reports distributed in the Royal College of Pathologists of Australasia (RCPA) and the Australasian Association of Clinical Biochemists (AACB) Chemical Pathology Patient Report Comments Program to assess the quality of interpretative commenting in clinical biochemistry in 2001. Method: Participants were asked to comment on a given set of biochemistry results attached with brief clinical details. All responses received were translated into key phrases and graphically presented on a histogram. An expert panel was asked to evaluate the appropriateness of the key phrases and to propose a suggested composite comment. Results: While the majority of comments received were felt to be acceptable by the expert panel, some comments were felt to be inappropriate or misleading. As comments on laboratory reports may affect clinical management of patients, it is important that these comments reflect accepted practice and current guidelines. Conclusion: The Patient Report Comments Program may play an important role in continuing education and possibly in quality assurance of interpretative commenting.