Root system distribution of sugar cane as related to nitrogen fertilization, evaluated by two methods: monolith and probes

Few studies on sugar cane have evaluated the root system of the crop, in spite of its importance. This is mainly due to the difficulty of evaluation and high variability of results. The objective of this study was to develop an evaluation method of the cane root system by means of probes so as to evaluate the mass, distribution and metabolically active roots related to N fertilization at planting. For this purpose, an experiment was conducted in an Arenic Kandiustults with medium texture in Jaboticabal/SP, in a randomized block design with four replications and four treatments: control (without N) and 40, 80 and 120 kg ha-1 of N applied in the form of urea in the planting furrow of the cane variety SP81 3250. One week before harvest, a urea-15N solution was applied at the cane stalk base to detect active metabolism in the root system. Trenches of 1.5 m length and 0.6 m depth were opened between two sugar cane rows for root sampling by two methods: monoliths (0.3, 0.2 and 0.15 m wide, deep and long respectively) taken from the trench wall and by probe (internal diameter 0.055 m). For each method, 15 samples per plot were collected. The roots were separated from the soil in a sieve (2 mm mesh), oven-dried (at 65 ºC) and the dry matter was measured. Root sampling by probes resulted in root mass that did not differ from the evaluation in monoliths, indicating that this evaluation method may be used for sugar cane root mass, although neither the root distribution in the soil profile nor the rhizome mass were efficiently evaluated, due to the small sample volume. Nitrogen fertilization at planting did not result in a greater root accumulation in the sugar cane plant, but caused changes in the distribution of the root system in the soil. The absence of N fertilization led to a better root distribution in the soil profile, with 50, 34 and 16 % in the 0-0.2, 0.2-0.4 and 0.4-0.6 m layers, respectively; in the fertilized treatments the roots were concentrated in the surface layer, with on average 70, 17 and 13 % for the same layers. The metabolically active roots were concentrated in the center of the cane stool, amounting to 40 % of the total root mass, regardless of N fertilization (application of 120 kg ha-1 N or without N).

Level shifts in a panel data based unit root test : an application to the rate of unemployment

Several unit root tests in panel data have recently been proposed. The test developed by Harris and Tzavalis (1999 JoE) performs particularly well when the time dimension is moderate in relation to the cross-section dimension. However, in common with the traditional tests designed for the unidimensional case, it was found to perform poorly when there is a structural break in the time series under the alternative. Here we derive the asymptotic distribution of the test allowing for a shift in the mean, and assess the small sample performance. We apply this new test to show how the hypothesis of (perfect) hysteresis in Spanish unemployment is rejected in favour of the alternative of the natural unemployment rate, when the possibility of a change in the latter is considered.

High b-value diffusion-weighted imaging: A sensitive method to reveal white matter differences in schizophrenia.

Over the last 10 years, diffusion-weighted imaging (DWI) has become an important tool to investigate white matter (WM) anomalies in schizophrenia. Despite technological improvement and the exponential use of this technique, discrepancies remain and little is known about optimal parameters to apply for diffusion weighting during image acquisition. Specifically, high b-value diffusion-weighted imaging known to be more sensitive to slow diffusion is not widely used, even though subtle myelin alterations as thought to happen in schizophrenia are likely to affect slow-diffusing protons. Schizophrenia patients and healthy controls were scanned with a high b-value (4000s/mm(2)) protocol. Apparent diffusion coefficient (ADC) measures turned out to be very sensitive in detecting differences between schizophrenia patients and healthy volunteers even in a relatively small sample. We speculate that this is related to the sensitivity of high b-value imaging to the slow-diffusing compartment believed to reflect mainly the intra-axonal and myelin bound water pool. We also compared these results to a low b-value imaging experiment performed on the same population in the same scanning session. Even though the acquisition protocols are not strictly comparable, we noticed important differences in sensitivities in the favor of high b-value imaging, warranting further exploration.

Host genetic determinants of spontaneous hepatitis C clearance

Acute infection with the hepatitis C virus (HCV) induces a wide range of innate and adaptive immune responses. A total of 20-50% of acutely HCV-infected individuals permanently control the virus, referred to as 'spontaneous hepatitis C clearance', while the infection progresses to chronic hepatitis C in the majority of cases. Numerous studies have examined host genetic determinants of hepatitis C infection outcome and revealed the influence of genetic polymorphisms of human leukocyte antigens, killer immunoglobulin-like receptors, chemokines, interleukins and interferon-stimulated genes on spontaneous hepatitis C clearance. However, most genetic associations were not confirmed in independent cohorts, revealed opposing results in diverse populations or were limited by varying definitions of hepatitis C outcomes or small sample size. Coordinated efforts are needed in the search for key genetic determinants of spontaneous hepatitis C clearance that include well-conducted candidate genetic and genome-wide association studies, direct sequencing and follow-up functional studies.

Observer-rated Coping Associated with Borderline Personality Disorder: An Exploratory Study.

BACKGROUND: Little is known about coping specificities, as operationalization of the concept of affect regulation, in borderline personality disorder (BPD). It is most important to take into account methodological criticisms addressed to the self-report questionnaire approach and to compare BPD coping specificities to the ones of neighbouring diagnostic categories, such as bipolar disorder (BD). SAMPLING AND METHODS: The present exploratory study compared the coping profiles of N = 25 patients presenting BPD to those of N = 25 patients presenting BD and to those of N = 25 healthy controls. All participants underwent a clinical interview that was transcribed and rated using the Coping Patterns observer-rater system. RESULTS: Results partially confirmed study hypotheses and showed differences between BPD patients and healthy controls in all coping domains (competence, resources and autonomy), whereas the only coping domain presenting a BPD-specific lack of skills, compared with the BD patients, was autonomy, a set of coping strategies facing stress appraised as challenge. These coping processes were linked to general and BPD symptomatology. CONCLUSIONS: These results extend conclusions of earlier studies on affect regulation processes in BPD and bear important clinical implications, in the context of dialectical behavior therapy and other therapeutic approaches. Limitations of this exploratory study, such as the small sample size, are acknowledged. Copyright © 2012 John Wiley & Sons, Ltd. KEY PRACTITIONER MESSAGE: Coping can be reliably assessed in the narrative process in an non-structured interview frame. Patients with borderline personality disorder present with a specific lack of skills in affect regulation related to autonomy issues, compared to patients with bipolar disorder and healthy controls. Lack of skills in accommodation to distressing emotions in borderline personality disorder is related to symptom gravity and may be treated using radical acceptance strategies.

Pediatric morphea (localized scleroderma): review of 136 patients.

BACKGROUND: Morphea is an autoimmune inflammatory sclerosing disorder that may cause permanent functional disability and disfigurement. OBJECTIVES: We sought to determine the clinical features of morphea in a large pediatric cohort. METHODS: We conducted a retrospective chart review of 136 pediatric patients with morphea from one center, 1989 to 2006. RESULTS: Most children showed linear morphea, with a disproportionately high number of Caucasian and female patients. Two patients with rapidly progressing generalized or extensive linear morphea and arthralgias developed restrictive pulmonary disease. Initial oral corticosteroid treatment and long-term methotrexate administration stabilized and/or led to disease improvement in most patients with aggressive disease. LIMITATIONS: Retrospective analysis, relatively small sample size, and risk of a selected referral population to the single site are limitations. CONCLUSIONS: These data suggest an increased prevalence of morphea in Caucasian girls, and support methotrexate as treatment for problematic forms. Visceral manifestations rarely occur; the presence of progressive problematic cutaneous disease and arthralgias should trigger closer patient monitoring.

Cycle length of spermatogenesis in shrews (mammalia: soricidae) with high and low metabolic rates and different mating systems.

The aim of the present study was to establish and compare the durations of the seminiferous epithelium cycles of the common shrew Sorex araneus, which is characterized by a high metabolic rate and multiple paternity, and the greater white-toothed shrew Crocidura russula, which is characterized by a low metabolic rate and a monogamous mating system. Twelve S. araneus males and fifteen C. russula males were injected intraperitoneally with 5-bromodeoxyuridine, and the testes were collected. For cycle length determinations, we applied the classical method of estimation and linear regression as a new method. With regard to variance, and even with a relatively small sample size, the new method seems to be more precise. In addition, the regression method allows the inference of information for every animal tested, enabling comparisons of different factors with cycle lengths. Our results show that not only increased testis size leads to increased sperm production, but it also reduces the duration of spermatogenesis. The calculated cycle lengths were 8.35 days for S. araneus and 12.12 days for C. russula. The data obtained in the present study provide the basis for future investigations into the effects of metabolic rate and mating systems on the speed of spermatogenesis.

Role of hepatitis C virus genotype 3 in liver fibrosis progression: a systematic review and meta-analysis.

The progression of liver fibrosis in chronic hepatitis C has long been considered to be independent from viral genotypes. However, recent studies suggest an association between Hepatitis C virus (HCV) genotype 3 and accelerated liver disease progression. We completed a systematic review and meta-analysis of studies evaluating the association between HCV genotypes and fibrosis progression. PubMed, Embase and ISI Web of Knowledge databases were searched for cohort, cross-sectional and case-control studies on treatment-naïve HCV-infected adults in which liver fibrosis progression rate (FPR) was assessed by the ratio of fibrosis stage in one single biopsy to the duration of infection (single-biopsy studies) or from the change in fibrosis stage between two biopsies (paired biopsies studies). A random effect model was used to derive FPR among different HCV genotypes. Eight single-biopsy studies (3182 patients, mean/median duration of infection ranging from 9 to 21 years) and eight paired biopsies studies (mean interval between biopsies 2-12 years) met the selection criteria. The odds ratio for the association of genotype 3 with accelerated fibrosis progression was 1.52 (95% CI 1.12-2.07, P = 0.007) in single-biopsy studies and 1.37 (95% CI 0.87-2.17, P = 0.17) in paired biopsy studies. In conclusion, viral genotype 3 was associated with faster fibrosis progression in single-biopsy studies. This observation may have important consequences on the clinical management of genotype 3-infected patients. The association was not significant in paired biopsies studies, although the latter may be limited by important indication bias, short observation time and small sample size.

Statistical properties of new neutrality tests against population growth.

A number of statistical tests for detecting population growth are described. We compared the statistical power of these tests with that of others available in the literature. The tests evaluated fall into three categories: those tests based on the distribution of the mutation frequencies, on the haplotype distribution, and on the mismatch distribution. We found that, for an extensive variety of cases, the most powerful tests for detecting population growth are Fu"s FS test and the newly developed R2 test. The behavior of the R2 test is superior for small sample sizes, whereas FS is better for large sample sizes. We also show that some popular statistics based on the mismatch distribution are very conservative. Key words: population growth, population expansion, coalescent simulations, neutrality tests

Prevalence and correlates of DSM-5 bipolar and related disorders and hyperthymic personality in the community.

BACKGROUND: To 1) establish the lifetime and 12-month prevalence of DSM-5 bipolar and related disorders including the new algorithmically defined conditions grouped within Other Specified Bipolar and Related Disorders (OSBARD) as well as hyperthymic personality in a randomly selected community sample, and 2) determine the clinical relevance of the OSBARD category in terms of sociodemographic characteristics, course, comorbidity and treatment patterns by comparing the subjects of this category to those with bipolar-I (BP-I), bipolar-II (BP-II), major depressive disorder (MDD), and those with no history of mood disorders. METHODS: The semi-structured Diagnostic Interview for Genetic Studies was administered by masterslevel psychologists to a random sample of an urban area (n=3'719). RESULTS: The lifetime prevalence was 1.0% for BP-I, 0.8% for BP-II, 1.0% for OSBARD and 3% for hyperthymic personality. Subjects with OSBARD were more severely affected than subjects without a history of mood disorders regarding almost all clinical correlates. Compared to those with MDD, they also revealed an elevated risk of suicidal attempts, lower global functioning, more treatment seeking and more lifetime comorbidity including anxiety, substance use and impulse-control disorders. However, they did not differ from subjects with BP-II. LIMITATIONS: Small sample sizes for bipolar and related disorders and potential inaccurate recall of symptoms. CONCLUSIONS: The modifications of diagnostic criteria for manic/hypomanic episodes according to the DSM-5 only marginally affect the prevalence estimates for BP-I and BP-II. The new DSM-5 OSBARD category is associated with significant clinical burden, is hardly distinct from BP-II with respect to clinical correlates and deserves similar clinical attention.

Viral genotype-specific role of PNPLA3, PPARG, MTTP, and IL28B in hepatitis C virus-associated steatosis.

BACKGROUND & AIMS: Steatosis is a prominent feature of hepatitis C, especially in patients infected with genotype 3. The analysis of genetic polymorphisms influencing steatosis in chronic hepatitis C has been limited by the studies' small sample size, and important single nucleotide polymorphisms (SNPs), such as those in the patatin-like phospholipase family 3 protein (PNPLA3), were never evaluated. METHODS: We analyzed the role of SNPs, from 19 systematically selected candidate genes, on steatosis in 626 Caucasian hepatitis C virus (HCV) infected patients. SNPs were extracted from a genome-wide association-generated dataset. Associations of alleles with the presence and/or different severity of steatosis were evaluated by univariate and multivariate logistic regression, accounting for all relevant covariates. RESULTS: The risk of steatosis was increased by carriage of I148M in PNPLA3, but only in patients with HCV genotypes non-3 (odds ratio [OR]=1.9, 95% confidence interval [CI]=1.6-2.3, p<0.001) and similar, albeit weaker associations were found for SNPs in peroxisome proliferator-activated receptor-γ (PPARG) and interleukin-28B (IL28B). Carriage of a SNP in the microsomal triglyceride transfer protein (MTTP) increased the risk of steatosis, but only in patients with HCV genotype 3 (rs1800803, OR=3.4, 95% CI=2.4-4.9, p=0.001). CONCLUSIONS: The rs738409 SNP in PNPLA3 is associated with an increased risk of steatosis in patients infected with HCV genotypes non-3. Host genes affect steatosis depending on the infecting HCV genotype, suggesting their interaction with viral factors.

Reflections on Partial Least Squares Path Modeling

The purpose of the present article is to take stock of a recent exchange in Organizational Research Methods between critics (Rönkkö & Evermann, 2013) and proponents (Henseler et al., 2014) of partial least squares path modeling (PLS-PM). The two target articles were centered around six principal issues, namely whether PLS-PM: (1) can be truly characterized as a technique for structural equation modeling (SEM); (2) is able to correct for measurement error; (3) can be used to validate measurement models; (4) accommodates small sample sizes; (5) is able to provide null hypothesis tests for path coefficients; and (6) can be employed in an exploratory, model-building fashion. We summarize and elaborate further on the key arguments underlying the exchange, drawing from the broader methodological and statistical literature in order to offer additional thoughts concerning the utility of PLS-PM and ways in which the technique might be improved. We conclude with recommendations as to whether and how PLS-PM serves as a viable contender to SEM approaches for estimating and evaluating theoretical models.

Efectos de la visualización motora como parte del tratamiento de fisioterapia en pacientes con lesión medular

Actualmente, las lesiones medulares son muy frecuentes y suelen provocar una repentina pérdida de autonomía; así pues, es importante el estudio de los posibles tratamientos teniendo como finalidad el incremento de la funcionalidad de las personas afectadas por este tipo de lesión. La visualización motora es una técnica utilizada desde hace muchos años en el ámbito del deporte, pero está muy poca estudiada en personas sufriendo algún tipo de lesión medular incompleta. El interés de esta técnica viene también de la poca cantidad de recursos económicos que necesita su utilización. El presente proyecto explica la elaboración de un estudio mixto que tiene como principal objetivo el estudio de los efectos de la visualización motora como parte del tratamiento de fisioterapia en pacientes sufriendo una lesión medular incompleta, mediante una aplicación de esta técnica enfocada en los miembros afectados por la lesión. Se propone entonces realizar un tratamiento a pacientes ingresados en centros especializados en lesión medular. Las limitaciones del estudio son el posible abandono de algún participante, el pequeño tamaño de la muestra y la dificultad para valorar la real implicación de las personas participantes.

Beneficis de la realització d'un programa d'activitat física per persones maniacodepressives

Proposit: L'objectiu d'aquest treball és analitzar quins efectes produeix un programa d'activitat física en pacients amb trastorn bipolar de tipus II. Mètodes: Per la realització d'aquest estudi he comptat amb una mostra petita (n=14), la qual estava dividida en grup control (n=7) i grup intervenció (n=7). Es va realitzar una valoració inicial de la mostra per mitjà del Yesavage i SF-12. Posteriorment el grup intervenció va participar en 20 sessions d'activitat física (freq: 2/set). Un cop finalitzat el programa es va tornar a valorar la mostra per mitjà del Yesavage i SF-12. Resultats: Els subjectes del grup intervenció van millorar en: Estat d'ànim (Yesavage), Percepció de la pròpia salut, nivell d'energia i sentiment de tristesa i desànim. En l'estat de tranquil·litat i calma no van mostrar una gran variació. Conclusions: La pràctica d'activitat física en grup millora l'estat d'ànim, percepció de pròpia salut, redueix l'estat de tristesa i desànim i nivell d'energia.

Outcome evaluation of ankle osteoarthritis treatments using spatio-temporal gait parameters and plantar pressure during unconstrained long distance walking : P25

Introduction: Ankle arthrodesis (AD) and total ankle replacement (TAR) are typical treatments for ankle osteoarthritis (AO). Despite clinical interest, there is a lack of their outcome evaluation using objective criteria. Gait analysis and plantar pressure assessment are appropriate to detect pathologies in orthopaedics but they are mostly used in lab with few gait cycles. In this study, we propose an ambulatory device based on inertial and plantar pressure sensors to compare the gait during long-distance trials between healthy subjects (H) and patients with AO or treated by AD and TAR. Methods: Our study included four groups: 11 patients with AO, 9 treated by TAR, 7 treated by AD and 6 control subjects. An ambulatory system (Physilog®, CH) was used for gait analysis; plantar pressure measurements were done using a portable insole (Pedar®-X, DE). The subjects were asked to walk 50 meters in two trials. Mean value and coefficient of variation of spatio-temporal gait parameters were calculated for each trial. Pressure distribution was analyzed in ten subregions of foot. All parameters were compared among the four groups using multi-level model-based statistical analysis. Results: Significant difference (p <0.05) with control was noticed for AO patients in maximum force in medial hindfoot and forefoot and in central forefoot. These differences were no longer significant in TAR and AD groups. Cadence and speed of all pathologic groups showed significant difference with control. Both treatments showed a significant improvement in double support and stance. TAR decreased variability in speed, stride length and knee ROM. Conclusions: In spite of a small sample size, this study showed that ankle function after AO treatments can be evaluated objectively based on plantar pressure and spatio-temporal gait parameters measured during unconstrained walking outside the lab. The combination of these two ambulatory techniques provides a promising way to evaluate foot function in clinics.