Characterization of Microcystis morphotypes: Implications for colony formation and intraspecific variation

Groundworks on Microcystis colony formation and morphological variation are critical to understanding the whole eco-cycle of Microcystis blooms. In this study, we tested the cell adhesion effect, an important pathway for colony formation, among Microcystis colonies of different morphotypes, and examined the potential linkage between cell properties and morphological plasticity. Results showed that cell adhesion significantly contributed to the aggregation of Microcystis colonies, but such adhesion only occurred in colonies belonging to the same morphotype. This suggests that Microcystis cannot form large colonies through a direct adhesion effect among different morphotypes, possibly due to substantial differences in the chemical structures and compositions of their extracellular polymeric substances (EPS). Cell functional features also varied substantially with morphotypes, implying high intraspecific variation in competitive and defensive strategies of Microcystis. Our results offer new insights into colony formation of Microcystis and substantiate the importance of fundamental chemical characteristics of EPS in determining the morphological plasticity.     

Influence of variants in the NPY gene on obesity and metabolic syndrome features in Spanish children

Variants in the neuropeptide Y (NPY) gene have been associated with obesity and its traits. The objective of the present study was to evaluate the association of single nucleotide polymorphisms (SNPs) in the NPY gene with obesity, metabolic syndrome features, and inflammatory and cardiovascular disease (CVD) risk biomarkers in Spanish children. We recruited 292 obese children and 242 normal-body mass index (BMI) children. Height, weight, BMI, waist circumference, clinical and metabolic markers, adipokines, and inflammatory (PCR, IL-6, IL-8 and TNF-α) and CVD risk biomarkers (MPO, MMP-9, sE-selectin, sVCAM, sICAM, and PAI-1) were analyzed. Seven SNPs in the NPY gene were genotyped. The results of our study indicate that anthropometric measurements, clinical and metabolic markers, adipokines (leptin and resistin), and inflammatory and CVD risk biomarkers were generally elevated in the obese group. The exceptions to this finding included cholesterol, HDL-c, and adiponectin, which were lower in the obese group, and glucose, LDL-c, and MMP-9, which did not differ between the groups. Both rs16147 and rs16131 were associated with the risk of obesity, and the latter was also associated with insulin resistance, triacylglycerols, leptin, and HDL-c. Thus, we confirm the association of rs16147 with obesity, and we demonstrate for the first time the association of rs16131 with obesity and its possible impact on the early onset of metabolic syndrome features, mainly triacylglycerols, in children.     

Persistence and vulnerability: Retaining biodiversity in the landscape and in protected areas

An objective of biodiversity conservation activities is to minimize the exposure of biodiversity features to threatening processes and to ensure, as far as possible, that biodiversity persists in the landscape. We discuss how issues of vulnerability and persistence can and should be addressed at all stages of the conservation planning and implementation process. Procedures for estimating the likelihood of persistence and for measuring degrees of vulnerability at different spatial and temporal scales using subjective assessments, rules of thumb and analytical and simulation models are reviewed. The application of information on vulnerability and persistence to conservation planning and management is discussed under the headings of natural dynamics, replication of protection, levels of representation, source and sink population structures, refuges and critical resources, reserve design, habitat fragmentation and levels of management.     

Correlation of receptive field position of mechanosensory neurons and the strength of their connections to AP neurons in the CNS of the leech (Whitmania pigra)

An identified neuron of unknown function in the CNS of the leech, the anterior pagoda (AP) cell, receives multiple synaptic inputs from mechanosensory neurons that innervate the skin. Impulses in touch (T), pressure (P) and nociceptive (N) sensory cells on both sides of the ganglion produced electrical coupling potentials on both AP cells. Sensory cells with receptive fields contralateral to the cell body of the AP neuron always gave rise to larger synaptic potentials. In addition sensory cells supplying dorsal skin gave rise to larger synaptic potentials than those with lateral or ventral fields. It is suggested that integration by the AP cell can provide information about the position of mechanical stimuli impinging on the body wall of the animal.