On the spatial distribution and nearest neighbor distance between particles in the water column determined from in situ holographic measurements

A film-based holography system was used in conjunction withinstrumentation that detected bioluminescent thin layers torecord the spatial distribution of zooplankton and their preyin the Gulf of Maine, USA. The holocamera and instruments weremounted on the Johnson Sea Link (JSL) in a setup that minimizedthe disturbance to the sample volume. More than 143 hologramswere automatically scanned to provide focused images of 5000–10000 particles and their three-dimensional coordinates in each894 cm³ sample. The reconstructed volumes provided clear imagesof intermingling copepods species, nauplii, Pseudonitzschiadiatoms and particles in the 10 µm–5 mm size range.Spatial analysis of the nearest neighbor distance (NND) of thesmallest particles showed a random distribution, but detritusparticles showed small-scale clustering in regions below thepycnocline. A detritus maximum, found several meters below thepycnocline, at 20–30 m, was determined to be caused byfecal pellets in various stages of degradation. This regionalso contained elevated concentrations of calanoids, cyclopoidsand harpacticoids. In one third of the cases, the harpacticoids,Aegisthus sp, were attached to detritus.     

Altered Hypercoagulability Factors in Patients with Chronic Chagas Disease: Potential Biomarkers of Therapeutic Response

Thromboembolic events were described in patients with Chagas disease without cardiomyopathy. We aim to confirm if there is a hypercoagulable state in these patients and to determine if there is an early normalization of hemostasis factors after antiparasitic treatment. Ninety-nine individuals from Chagas disease-endemic areas were classified in two groups: G1, with T.cruzi infection (n = 56); G2, healthy individuals (n = 43). Twenty-four hemostasis factors were measured at baseline. G1 patients treated with benznidazole were followed for 36 months, recording clinical parameters and performance of conventional serology, chemiluminescent enzyme-linked immunosorbent assay (trypomastigote-derived glycosylphosphatidylinositol-anchored mucins), quantitative polymerase chain reaction, and hemostasis tests every 6-month visits. Prothrombin fragment 1+2 (F1+2) and endogenous thrombin potential (ETP) were abnormally expressed in 77% and 50% of infected patients at baseline but returned to and remained at normal levels shortly after treatment in 76% and 96% of cases, respectively. Plasmin-antiplasmin complexes (PAP) were altered before treatment in 32% of G1 patients but normalized in 94% of cases several months after treatment. None of the patients with normal F1+2 values during follow-up had a positive qRT-PCR result, but 3/24 patients (13%) with normal ETP values did. In a percentage of chronic T. cruzi infected patients treated with benznidazole, altered coagulation markers returned into normal levels. F1+2, ETP and PAP could be useful markers for assessing sustained response to benznidazole.     

An evaluation of the genetic connectivity and temporal stability of the blue and red shrimp Aristeus antennatus: a case study of spawning females’ grounds in the Western Mediterranean Sea

Hydrobiologia - The blue and red shrimp Aristeus antennatus has been intensively exploited by trawling fishery in the Western Mediterranean Sea. Implementation of an adequate management plan needs...     

A chromaticity‐based technique for estimation of above‐ground plant biomass

Abstract. This paper presents a new and simple technique to derive quantitative estimates of green or dry biomass using colour information from digital pictures. This pixel‐counting technique is based on the association of particular plant material with a representative region on a two‐dimensional colour space, and applies to cases of non‐overlapping canopies. The efficacy of the method is demonstrated using sets of samples obtained from both field and laboratory studies. It is shown that application of the proposed approach results in a highly linear relationship between pixel count and foliar area for both green and non‐green material [r= 0.99 (p < 0.001)]. Analysis of images from a short‐grass steppe shows a high correlation between pixel count and measured values of green biomass [r= 0.95 (p < 0.001)]. The method outlined here allows for a substantial improvement in the speed of sample evaluation to estimate biomass both in the field and in the laboratory. It also provides a non‐destructive alternative to monitor plant cover and biomass in open canopies.