POPULATION DYNAMICS AND SPAWNING OF THE FLATFISH SOLEA BLEEKERI AND PSEUDORHOMBUS ARSIUS IN THE INTERTIDAL AREA OF INHACA ISLAND, MO&#199AMBIQUE

The population dynamics of flatfish Solea bleekeri and Pseudorhombus arsius within the intertidal area of Inhaca Island, Moçambique, was investigated using bottom trawl data collected during summer (December 1996–March 1997) and winter (June 1997–August 1997). The endemic S. bleekeri is a small, relatively slowgrowing species with low rates of natural mortality. Densities of juveniles were significantly greater in winter (24.7 fish 1 000 m-2) than in summer (10.8 fish 1 000 m-2), probably because of intensive spawning during summer. Greater catches of S. bleekeri were taken by night than by day. Densities of P. arsius did not differ significantly between day and night or among seasons. Mean density of P. arsius was 53 fish 1 000 m-2 for the survey. Both species preferred the same substrata, significantly greater densities being found on the mudflats and in the tidal channels. Both seem to complete two life cycles within a year.Afr. J. mar. Sci. 25: 49–6

Early Mechanical Alterations in Phospholamban Mutation Carriers: Identifying Subclinical Disease Before Onset of Symptoms

OBJECTIVES: This study aimed to explore echocardiographic characteristics of phospholamban (PLN) p.Arg14del mutation carriers to investigate whether structural and/or functional abnormalities could be identified before onset of symptoms. BACKGROUND: Carriers of the genetic PLN p.Arg14del mutation may develop arrhythmogenic and/or dilated cardiomyopathy. Overt disease is preceded by a pre-symptomatic phase of variable length in which disease expression seems to be absent. METHODS: PLN p.Arg14del mutation carriers with an available echocardiogram were included. Mutation carriers were classified as pre-symptomatic if they had no history of ventricular arrhythmias (VAs), a premature ventricular complex count of <500/24 h, and a left ventricular (LV) ejection fraction of ≥45%. In addition, we included 70 control subjects with similar age and sex distribution as the pre-symptomatic mutation carriers. Comprehensive echocardiographic analysis (including deformation imaging) was performed. RESULTS: The final study population consisted of 281 PLN p.Arg14del mutation carriers, 139 of whom were classified as pre-symptomatic. In comparison to control subjects, pre-symptomatic mutation carriers had lower global longitudinal strain and higher LV mechanical dispersion (both p < 0.001). In addition, post-systolic shortening (PSS) in the LV apex was observed in 43 pre-symptomatic mutation carriers (31%) and in none of the control subjects. During a median follow-up of 3.2 years (interquartile range: 2.1 to 5.6 years) in 104 pre-symptomatic mutation carriers, nonsustained VA occurred in 13 (13%). Presence of apical PSS was the strongest echocardiographic predictor of VA (multivariable hazards ratio: 5.11; 95% confidence interval [CI]: 1.37 to 19.08; p = 0.015), which resulted in a negative predictive value of 96% (95% CI: 89% to 98%) and a positive predictive value of 29% (95% CI: 21% to 40%). CONCLUSIONS: Global and regional LV mechanical alterations in PLN p.Arg14del mutation carriers precede arrhythmic symptoms and overt structural disease. Pre-symptomatic mutation carriers with normal deformation patterns in the apex are at low risk of developing VA within 3 years, whereas mutation carriers with apical PSS appear to be at higher risk

Distinct molecular signature of phospholamban p.Arg14del arrhythmogenic cardiomyopathy.

Phospholamban (PLN) p.Arg14del cardiomyopathy is characterized by a distinct arrhythmogenic biventricular phenotype that can be predominantly left ventricular, right ventricular, or both. Our aim was to further elucidate distinct features of this cardiomyopathy with respect to the distribution of desmosomal proteins observed by immunofluorescence (IF) in comparison to desmosomal arrhythmogenic cardiomyopathy and co-existent genetic variants. We studied eight explanted heart specimens from PLN p.Arg14del mutation carriers. Macro- and microscopic examination revealed biventricular presence of fibrofatty replacement and interstitial fibrosis. Five out of 8 (63%) patients met consensus criteria for both arrhythmogenic right ventricular cardiomyopathy (ARVC) and dilated cardiomyopathy (DCM). In four cases, targeted next-generation sequencing revealed one additional pathogenic variant and six variants of unknown significance. IF showed diminished junction plakoglobin signal intensity at the intercalated disks in 4 (67%) out of 6 cases fulfilling ARVC criteria but normal intensity in both cases fulfilling only DCM criteria. Notably, the four cases with diminished junction plakoglobin were also those where an additional gene variant was detected. IF for two proteins recently investigated in desmosomal arrhythmogenic cardiomyopathy (ACM), synapse-associated protein 97 and glycogen synthase kinase-3 beta, showed a distinct distributional pattern in comparison to desmosomal ACM. In 7 (88%) out of 8 cases we observed both a strong synapse-associated protein 97 signal at the sarcomeres and no glycogen synthase kinase-3 beta translocation to the intercalated discs. Phospholamban p.Arg14del cardiomyopathy is characterized by a distinct molecular signature compared to desmosomal ACM, specifically a different desmosomal protein distribution. This study substantiates the idea that additional genetic variants play a role in the phenotypical heterogeneity

Accelerated in vivo proliferation of memory phenotype CD4+ T-cells in human HIV-1 infection irrespective of viral chemokine co-receptor tropism.

CD4(+) T-cell loss is the hallmark of HIV-1 infection. CD4 counts fall more rapidly in advanced disease when CCR5-tropic viral strains tend to be replaced by X4-tropic viruses. We hypothesized: (i) that the early dominance of CCR5-tropic viruses results from faster turnover rates of CCR5(+) cells, and (ii) that X4-tropic strains exert greater pathogenicity by preferentially increasing turnover rates within the CXCR4(+) compartment. To test these hypotheses we measured in vivo turnover rates of CD4(+) T-cell subpopulations sorted by chemokine receptor expression, using in vivo deuterium-glucose labeling. Deuterium enrichment was modeled to derive in vivo proliferation (p) and disappearance (d*) rates which were related to viral tropism data. 13 healthy controls and 13 treatment-naive HIV-1-infected subjects (CD4 143-569 cells/ul) participated. CCR5-expression defined a CD4(+) subpopulation of predominantly CD45R0(+) memory cells with accelerated in vivo proliferation (p = 2.50 vs 1.60%/d, CCR5(+) vs CCR5(-); healthy controls; P<0.01). Conversely, CXCR4 expression defined CD4(+) T-cells (predominantly CD45RA(+) naive cells) with low turnover rates. The dominant effect of HIV infection was accelerated turnover of CCR5(+)CD45R0(+)CD4(+) memory T-cells (p = 5.16 vs 2.50%/d, HIV vs controls; P<0.05), naïve cells being relatively unaffected. Similar patterns were observed whether the dominant circulating HIV-1 strain was R5-tropic (n = 9) or X4-tropic (n = 4). Although numbers were small, X4-tropic viruses did not appear to specifically drive turnover of CXCR4-expressing cells (p = 0.54 vs 0.72 vs 0.44%/d in control, R5-tropic, and X4-tropic groups respectively). Our data are most consistent with models in which CD4(+) T-cell loss is primarily driven by non-specific immune activation

Entanglement Entropy for Singular Surfaces

We study entanglement entropy for regions with a singular boundary in higher dimensions using the AdS/CFT correspondence and find that various singularities make new universal contributions. When the boundary CFT has an even spacetime dimension, we find that the entanglement entropy of a conical surface contains a term quadratic in the logarithm of the UV cut-off. In four dimensions, the coefficient of this contribution is proportional to the central charge 'c'. A conical singularity in an odd number of spacetime dimensions contributes a term proportional to the logarithm of the UV cut-off. We also study the entanglement entropy for various boundary surfaces with extended singularities. In these cases, similar universal terms may appear depending on the dimension and curvature of the singular locus.Comment: 66 pages,4 figures. Some typos are removed and a reference is adde

Phospholamban immunostaining is a highly sensitive and specific method for diagnosing phospholamban p.Arg14del cardiomyopathy

Phospholamban (PLN) p.Arg14del cardiomyopathy is associated with an increased risk of malignant ventricular arrhythmias and severe heart failure and a poor prognosis from late adolescence. It can be diagnosed in whole heart specimens, but rarely in right ventricular biopsy specimens, by PLN immunohistochemistry showing PLN-containing aggregates concentrated in cardiomyocytes in dense perinuclear aggresomes. The purpose of this study was to determine whether PLN immunohistochemistry can be used to diagnose PLN p.Arg14del cardiomyopathy using apical left ventricular myocardial specimens harvested during left ventricular assist device (LVAD) implantation. At that stage, a genetic diagnosis, which may guide treatment and referral of family members for further investigation, is frequently not established yet. Included were myocardial specimens from 30 diverse genetic cardiomyopathy cases with known variants (9 carriers of the pathogenic PLN p.Arg14del variant, 18 cases with other pathogenic or likely pathogenic variants in cardiomyopathy-related genes, and 3 with only variants of unknown significance). Immunohistochemical analysis revealed typical dense perinuclear globular PLN-positive aggregates, representing aggresomes, in all nine PLN p.Arg14del cases. In 20 non-PLN cases, PLN-staining was absent. In one non-PLN case, one of the two independent observers misinterpreted PLN staining of heavily wrinkled nuclear membranes of cardiomyocytes as perinuclear PLN aggregates. In this genetic cardiomyopathy cohort, PLN Immunohistochemical analysis in LVAD biopsies was found to be a highly sensitive (100%) and specific (95%) method for demonstration of PLN protein aggregates in PLN p.Arg14del cardiomyopathy. In clinical practice, PLN immunohistochemical analysis of LVAD specimens can be of incremental value in the diagnostic workup of this cardiomyopathy, even more so if genetic analysis is not readily available

STUDI EKSPERIMENTAL KARAKTERISTIK KUAT TEKAN DAN KARAKTERISTIK PEMBAKARAN BRIKET DAUN CENGKEH DAN JERAMI PADI

Penelitian ini mempelajari tentang karakteristik kuat tekan dan karakteristik pembakaran briket daun cengkeh dan jerami padi. Pembriketan dilakukan dengan menggunakan mesin pres hidrolik dengan tekanan pembriketan sebesar 450 kg/cm2, dengan bahan pengikat dan tanpa bahan pengikat. Bahan pengikat yang digunakan adalah lem kanji dengan kadar 5 %. Briket berbentuk silinder dengan diameter sekitar 3 cm dan tinggi 5 cm. Variasi parameter pembriketan yang digunakan adalah ukuran butir 20, 40 dan 80 mesh, kadar air 15 %, 20 % dan 25 %, serta suhu pembriketan sebesar 60 oC, 80 oC, 100 oC dan 120 oC. Uji pembakaran dilakukan dalam tungku berbentuk tabung horisontal berdiameter dalam 170 mm. Variasi perameter uji pembakaran yang digunakan adalah kecepatan aliran udara sebesar 0,6 m/s; 0,8 m/s; 1,0 m/s dan 1,2 m/s serta variasi ukuran butir sebesar 20, 40, dan 80 mesh. Suhu pembriketan berpengaruh signifikan terhadap peningkatan kuat tekan briket. Dari hasil uji pembakaran dapat ditentukan besarnya laju pembakaran, profil suhu pembakaran, nilai energi aktivasi (E ), konstanta Arrhenius (A), dan emisi CO. Dari semua percobaan, kadar emisi CO puncak lebih dari 400 ppm. Kata kunci: kuat tekan, daun cengkeh, jerami, bahan pengikat, ukuran butir, suhu pembriketan, kadar air, laju pembakaran, energi aktivasi, emisi CO.

The Energy Loss of a Heavy Quark Moving in a Viscous Fluid

To study the rate of energy and momentum loss of a heavy quark in QGP, specifically in the hydrodynamic regime, we use fluid/gravity duality and construct a perturbative procedure to find the string solution in gravity side. We show that by this construction the drag force exerted on the quark can be computed perturbatively, order by order in a boundary derivative expansion. At ideal order, our result is just the drag force exerted on a moving quark in thermal plasma with thermodynamics variables promoted to become local functions of space and time. Furthermore, we apply this procedure to a transverse quark in Bjorken flow and compute the first-derivative corrections, namely the viscous corrections, to the drag force.Comment: 33 pages, 6 figures, references added v5: Some correction

Prediction of ventricular arrhythmia in phospholamban p.Arg14del mutation carriers–reaching the frontiers of individual risk prediction

Aims: This study aims to improve risk stratification for primary prevention implantable cardioverter defibrillator (ICD) implantation by developing a new mutation-specific prediction model for malignant ventricular arrhythmia (VA) in phospholamban (PLN) p.Arg14del mutation carriers. The proposed model is compared to an existing PLN risk model. / Methods and results: Data were collected from PLN p.Arg14del mutation carriers with no history of malignant VA at baseline, identified between 2009 and 2020. Malignant VA was defined as sustained VA, appropriate ICD intervention, or (aborted) sudden cardiac death. A prediction model was developed using Cox regression. The study cohort consisted of 679 PLN p.Arg14del mutation carriers, with a minority of index patients (17%) and male sex (43%), and a median age of 42 years [interquartile range (IQR) 27-55]. During a median follow-up of 4.3 years (IQR 1.7-7.4), 72 (10.6%) carriers experienced malignant VA. Significant predictors were left ventricular ejection fraction, premature ventricular contraction count/24 h, amount of negative T waves, and presence of low-voltage electrocardiogram. The multivariable model had an excellent discriminative ability {C-statistic 0.83 [95% confidence interval (CI) 0.78-0.88]}. Applying the existing PLN risk model to the complete cohort yielded a C-statistic of 0.68 (95% CI 0.61-0.75). / Conclusion: This new mutation-specific prediction model for individual VA risk in PLN p.Arg14del mutation carriers is superior to the existing PLN risk model, suggesting that risk prediction using mutation-specific phenotypic features can improve accuracy compared to a more generic approach